Chinese audio companies have really stepped up their design and manufacturing game in recent years. They don't all look like bland, boring black boxes anymore. They've also put effort into designing better circuits and using quality components. It's also nice that they are pro tinkering and responsive to their customers' feedback. A lot of companies don't want customers to open up their product.
Great little amp with lots of possibilities. Have to mention however, that tnt reviews reviewed these in mono mode against the zerozone chip mono amps. They favored the overall sound presentation of the zerozones over the za3’s considerably. And they aren’t much more in cost. They can also accept opamp upgrades. Would love to get your impressions on those as well 🙏🏼👍🏼
TNT failed to mention whether the ZA3 was tested with RCA or XLR input. Quite a large omission considering Lachlan's statement on the quality difference between those connections on this specific amp.
I'm running Fosi ZA3 x 2 in mono mode (balanced) into Sony SS-CS5 speakers in my gym. I've also tried them with Klipsch RP600MII speakers. With either speaker setup and proper placement, the amps sound lush, spacious, energetic and vibey, with just enough bass. They also permit channel balancing to fix a suboptimal room shape! I have no desire to further tweak this setup, even though with this hobby I suppose you can never say never.
Amazing video, this makes me excited as a stereo Za3 user who actually doesn't mind how it sounds on RCA, however I'm happy to hear that going XLR and adding another unit as mono only provide further improvement from this point, interesting arguments against the V3 mono and how the different Op Amps can bring tonalities which can add or detract from the overall experience, if only there was a similarly priced DAC to go along with it, with enough body not to sound analytical and thin that someone could use XLR out of, Thank you for the content.
@@djb5864I'd go with a schiit amp too. A Gjallarhorn is the same price as mono za3, and probably better in everyday use with most speakers. If you need to go to 100db, or have very low sensitivity, I suppose the za3 may do that better. I don't have a za3, but I'm going to replace a V3 stereo with a Schiit amp after using a 2w Rekkr in a different setup. It sounds much more alive and pleasing.
@@PassionforSound if you look at the price of the fosi v3 you cant believe it, i tryed the 48v 10amp power supply on it and i like the standard 32v better no difference on my speakers ! Its for the money best buy of alltime haha
@@9XThunder If you see this I'd like to know: does "downgrading" the power supply reduce the gain at all? My main complaint about the za3 is the gain is just way too high, but I have the 48v 5a supply and I don't know if that is a factor.
@@lisar3944 what I notice with a 48v power supply is a little more dynamic but also more noise, what you have to do is listen to music not your equipment ;)
The different power supplies alter the maximum power available, but not the gain AFAIK so you'd need to find an alternative way to lower the signal level, I think.
Really informative video. I run Schiit Gjallarhorns in mono in my office setup. But looking for a inexpensive mono-block setup for my living room 2 channel setup. This video was very useful!
Sorry, but I don't have space in schedule for that. My thoughts would be to swap the amp as a first priority because it has more impact there, but do both if you can to get the maximum sound quality.
I bought the 48V version too because it’s cheap, has XLR input, has sub output, can be mono and powerful even though I have no speakers yet. I use it to power the HFM Susvara headphone but haven’t done any critical listening yet, I have other amps for it. Also, using this as a standby in case I do get a pair of speakers. My friend borrowed it when his amp went for repairs and love it. Looks like he is buying the Mono V3s
Please don't use class D amps for headphones! Where these weren't designed for the high impedance loads that headphones have relative to speakers, it can cause a massive spike in ultrasonic frequencies, which may be a risk for hearing loss even though we cant hear that high. Goldensound done a writeup on it with some measurements that you can google. - Unless you know this, of course, and you use an impedance adapter. In which case this is important to mention so that people who are unaware won't make the mistake of using a class D speaker amp without one.
Thanks for another really informative video lachlan. I trust you'll take this as the compliment it's intended to be - I see your approach and presentation quite similar to Tarun (A British Audiophile). Calm, informed and never over the top which is much appreciated. A quick question if I may - if I was going to buy the Burson V7V ops amps for my pair of ZA3's, would it be 2 or 1 per amp? I only use the XLR connections. Thank you
Hi Denis and thanks for the feedback! You can use just one upgraded op-amp in the ZA3, but I found putting one in the R channel and one in the XLR op-amp socket improved the sound even further.
Just placed 4 LM 4562 chips into the ZA3. LM 4562 : "gift to the audio hobbyist from the industry". I left one subwoofer socket with the original chip...everything else replaced. Also placed one of the LM 4562's in the XLR chip socket..... One word: Wow ! Only £20 for four LM 4562's. The ZA3 copes very well with these high speed chips...no oscillation. Crystal clear instruments and vocals.
Whats the point of having additional opamps on an amp? Isnt it like the signal which is comming from DAC has already gone thru opamps and just needs to be amplified without any further processing? How often do you want to hunt the signal thru opamps, on every single stage of the chain? Also ZA3 and ZD3 have no Headphones jacks which makes the whole chain to the biggest joke ever.
@Joe-Tump op-amps aren't just for adding gain to the signal (i.e. amplification). They are used in almost all audio devices because they control the interface between one device and the next to ensure the right amount of current is available to deliver the signal into the next part of the source chain.
@@PassionforSound But do opams affect the quality of sound on the amp stage too and if so should they? In case where you can roll opamps on DAC and AMP whats the purpose on doing it on both stages?
@Joe-Tump rolling op-amps is all about improving the performance of the device because many devices are built to a budget with lower quality op-amps. They will affect the sound of every device they're in because they're an integral part of the signal path in every device.
I have some of these coming in to test with the za3 and others. As of now, the main issues with the za3 is it's lack of treble and dullness in revealing systems. Sparkos op amps are an improvement, but I'd still like some more treble. Dual mono is the only way to go with the za3 in my opinion as well. I'm hopeful the burson op amps can bring the treble to the party. I guess, we'll see. So far v3 monos are way better than the za3 at top end performance, and more natural in my set ups. I'd be happy to change my mind with this op amp upgrade, if it is true...
The V7 Vivids really lift the sound of the ZA3s. If the V7s could fit comfortably in the V3 Monos, they'd be my choice, but sadly the case is just that little bit too small. ☹️
Odd I measured the case of the v3 monos, it seems like they should fit in it, just barely, unless their measements listed online are wrong? I assume you tried to fit them in the v3 monos? @@PassionforSound I guess I'll figure it out for myself 😂
@intoitreviews the PCB sits higher than the bottom of the case (probably for ventilation). Another viewer said they could drop the PCB down a rung (there are grooves in the side of the case that hold the PCB) and fit the V7s, but I haven't tried that yet myself.
@@PassionforSound I can confirm they do fit. Barely but they do fit in the v3 monos... try again. Thanks for the shout out when you correct this information for the public 🎉
No soldering or any fancy technical knowledge. Just a screwdriver to open the case and some care and patience to align the pins on the op-amps correctly before pushing them in.
interesting... I decided to get the hifiman speaker adapter for headphones and I have now put the mono block amps to good use.... and the amps sound very very good with the harder to drive headphones like the Tungsten and the Hifiman He6 v2.... the op amp swaps sound much more relevant with headphones... plenty of headroom .... great setup for a great price... Fosi is getting ready to release a new ZD3 Dac.. I sure hope they opt for XLR from their new DAC to the V3 mono...
I auditioned the HE6se V2 the other day and found the treble to be too harsh at high volumes, but possibly due to them not being broken-in. My Tungsten are due any month (year?) now...
. Hey THANKS dixster. The HE Adapter was just what I was looking for (although an adapter cable might work too). Forget preamp capability, I don't even want a volume control on my headphone power amp. Now I want to try it on the Schiit Gjallarhorn with the Loki mini as a headphone amp combo. Thanks again. Acid Jazz, Funk & Brass 🔈🔉🔊
I've been thinking about getting that Hifiman speaker adapter for my 300b amp and DCA headphone 🎧. Do you think it will work 🤔 or is it to much ohm power for headphone s?
@@DragnetSound should work fine... you will either need to build or buy a cable to hook it up.. all I did was get a nice speaker cable from Amazon and some connectors... braided the wires and put on the speaker jacks... works really well...
I need to correct you on something. The XLR opamp does not have the same function as the L+R opamps. According to the Fosi team on their forum. Good news, you only need a pair of Sparkos or Burson, not a quad. I put a pair decent ($7) OracleII 02 in the XLR position. It doesn't matter what you have in the sub positions for 20-150Hz. You can't hear that anyway. I replaced my 300B and Gato Amp150 for a pair of these. Better sound (just, depending on pref) and less power consumption in these expensive times. You do really need a transparent preamp on these (passive or higher priced). Mine is 4x the price of a ZA3
_"I need to correct you on something. The XLR opamp does not have the same function as the L+R opamps. According to the Fosi team on their forum. "_ Correct ... The dual op-amp coupled to the XLR inputs is used in differential mode to cancel noise and combine the phase opposite signals from the balanced input into a single ended signal for the rest of the circuit. The left and right op-amps are used as phase splitters to produce a direct and an inverted signal for the balanced inputs to the TPA3255 power amp chip. The subwoofer chips are in a low pass configuration, to remove signals above about 200hz from the output signal.
Thanks for an excellent review of the ZA3 A question about upgrading the op amps:If I intend to run these as monoblocs then why do I need to buy TWO pairs of op amps ? Thanks
You don't have to. The only one you HAVE to swap (if you're swapping) is the R channel op-amp. I found that swapping the op-amp up the back near the XLR sockets also helped to improve the sound slightly by improving the processing of the incoming signal.
Wouldn't it be better to swap the l/h channel op amp on mono going to l/h speaker and r/h opamp on mono going to r/h speaker? Thanks for any advice and for your channel😊@@PassionforSound
I'm not in front of the amps now, but from memory, there's a switch that changes these to mono mode and routes all signals through the right channel only which is why you only change that op-amp if using in mono mode.
I’m confused why you recommend 2 op-amps for mono operation. I’ve had outstanding results replacing only the Left XLR op amp, leaving the differential op amp and removing the rest of the unused op amps on the right and subwoofer channels. Could you explain?
You can definitely use just a single op-amp, but I found swapping both the XLR op-amp and the R channel op-amp gave even better performance. Basically, anywhere the signal is travelling will be improved with a better op-amp in the path.
If the Timekeepers are a 10 (they're the best I've heard in my setup along with the Enleum AMP-23R) then the ZA3 with op-amps is probably a 6. That's not a knock on the ZA3, just a reflection of the vast differences in design and price.
I recently got in my preorder of the V3 mono and I was bummed because I had heard the Burson V7 op amps didn't fit in the chassis. Today I was like f-it let me just open it up and see how it goes because I had some extra V7 Classics. If you look in the mono there are different slots in the chassis. Using the bottom slot they fit perfect! I thought the stock V3 Mono was a little too clinical with my KEF Q150s coming from using my 300b tube amp to drive them. I was missing all those thick mids. Boom those V7 Classics brought these monos right up to the perfect tuning for my taste. They brought the tube-y richness into the vocal midrange with the KEFs. Anyway, hope you have time to test it out with your V3 monos. I know you're a big fan of the V7s.
@@PassionforSound Yep totally! The Classics sound so good in the V3 Mono. I'm definitely not feeling like they are lean anymore. Love your reviews and opinions on everything btw. We have similar taste in sound signatures normally.
@@alenotta so are you running your V3 monos without the front and back plates? Because I don't see how they would fit with the pcb in a different position in the case 🤔
I'm using the Burson Voyager, but that's massive overkill. I'd just use the volume control that's built into most modern DACs. It's bit perfect and provides good control.
Hi, great discussion starter. I have a pair of V3 monos and am expecting the zd3 to be delivered soon. Would you prioritise rolling opamps in the zd3 preamp or in the v3 power amps first?
I don't know what rca cables you were using but it sounds fine through the rca to me, in fact I watch side by side sound blind test where the rca was said to sound better. I get zero background noise running these in mono mode at full volume through the rca's
I used identical RCA and XLR cables (either Supra Sword or Curious cables - I can't remember). The difference was significant on my setup, but there are many factors that could limit the maximum performance of a system and negate the differences between XLR and RCA.
@@PassionforSound I'm new to this kind of thing. Is it true that XLRs normally run at a higher volume? I know they are supposed to have less noise because of how the cables are designed
@@PassionforSound I have no desire to upgrade the op amps in these. I'm running some custom built Dayton audio reference series speakers and it sounds amazing!
What do you recommend guys for subwoofer op-amp in za3? will sub benefit from better or discreet op-amp, and if yes how does it impact performance? I am using Elac 2070. thanks
Oh, sorry. I thought you meant if you were driving a passive sub with the speaker output. Unfortunately, my answer is still the same. I would expect that the sound won't be much improved with upgraded op-amps for subs because they're low frequency only, but without testing it, I could be completely wrong.
Interesting...what is the difference in improvement if you replace the xlr opamp with something more affordable, and save the Bursons just for the l/r channel sockets? Most advice I've seen says to leave the xlr and sub out sockets alone and just focus on upgrading the main output opamps, so I'm especially interested in what is behind your rec to upgrade the xlr in, too. I recently tried a VMV A1 (as a speaker amp - I'm not a headphone listener yet) and while I liked it well enough, it just felt overall "meh" - nice enough but a bit too mellow. When I went back to my za3 I kinda sighed with relief. I'm a little bit embarrassed to like it so much, but as you say, it has an unusually natural sound - especially for class D. I have some Muses 8820's (allegedly very close to the Muses 02) that I want to swap in, but the Bursons are intriguing for sure - not sure I want to spring for 3 or 4 of them, though. If two might be plenty, I might be in!
There's a definite improvement in swapping the XLR socket op-amps as well as the output op-amps. I actually tested this again recently with a channel Patreon member so I'm certain it makes a difference, however I do believe that a lower grade op-amp in the XLR socket would be fine. Something like the MUSES you have would be perfect and then put the Bursons in the outputs only.
You don't need a preamp for headphones. For speakers, it depends a lot on your setup, but most modern DACs offer a perfectly good, bit perfect volume control already.
Enjoying this video (and the comments) very much, many thanks. Quick question, is it crucial to use the XLR (Balanced) instead of the RCA (Single-ended) input? Am i losing too much using the RCA input. Note: My DAC only has RCA output.
I just came back and watched this review -- you may remember me from a recent conversation about op-amp rolling in the comment thread of another video -- and I wonder if your test model of the ZA3 might have had some kind of problem with its RCA input? I'm using the RCA input and it's absolutely dominant over my beloved SMSL AO300.
@@PassionforSound Also very possible, but switching to balanced would be no big deal: The cash flow is there in a way that it isn't usually. The wrinkle is that I'd need a new DAC since my Arcam irDAC is only unbalanced-RCA out. As you may have seen, I watched your review of the SMSL D6s and I didn't miss that you think the $120 DACs out there are sonically indistinguishable --- but in my use-case (with two Fosi Audio ZA3's -- the SMSL would be the choice because of the balanced outputs, yes? Is there a slightly higher-end DAC (say $300USD or $400USD) that you would recommend instead?
You'd want a minimum of two: one for the L channel and one for the R channel. I also found benefits with upgrading the op-amp in the XLR processing socket of the amp. I haven't played around enough to know if the quality of op-amp is crucial there so you could maybe go with something a little cheaper there, but I'm not sure.
Hello, I love your reviews and this one with the op amps swap option among others is awesome. Now I have a technical question: If i got it right the Fosi Za3 has better quality XLR binding posts than RCA in this particular model. Now if I want to use the Za3 in Stereo Mode the XLR input do I have to swap just the one XLR op amp ? Or the 2 x RCA (right, left) + the XLR … means 3 op amps in total ( as mentioned in Stereo mode) ? Or just 1x the XLR? I mean this is until I can afford an other Za3 set to have it all in mono mode..
Your top priority in the ZA3 (in stereo mode) are the left and right op-amps. It's also good to swap the XLR op-amp, but slightly less important so you could wait until later or you could use a lower cost/quality op-amp compare to the L/R op-amps. So glad you're liking the reviews.
@@PassionforSound Awesome you answered my question! thank you I was wondering if I had to buy an extra Sparkos (I bought already 2 of them for right & left rca) and it improved the result right away .. and more from RCA now than from the XLR then I thought to make the most of this device so I have to purchase a 3rd Sparkos (my budget is not that extendable) ? So if I place a MUSE02 (way cheaper) in place of the Standard XLR that will work ? I was also worries that if I go with a different kind of op amp it would damage the device or kill the sound !? I have actually 2 x MUSES02
@@PassionforSound ? if you are only going to use the XLR connections of the ZA3 (in stereo mode), do you not only have to swap the left and right op-amps of the XLR? No need to also swap the RCA left en right op amps?
@flyindo if you're using it in stereo, you want to prioritise swapping the op-amps closest to the volume control - the left and right ones. The XLR op-amp (the single one at the back) does improve the sound but is less important than the L/R ones.
great review and recommendations...If I were using mono blocs of ZA3s with the OP amp upgrades, would I get better sonics if I used the balanced input or the coax? thanks
I bought a pair of the emotiva b2+ about a year ago. These speakers can be bi-amped. I didnt know what bi-amped meant at the time. Now i know and now i have a pair of the V3 monos. Im going to get another pair of V3s and bi-amp the b2+s. Has anyone done this yet?
You don't need another set.... switch the pair you have to stereo mode, use a Y connector on the input to tie L and R channels together ... feed the left channel into the tweeter and the right channel into the woofer.
I have a pair of the Maggie LRS+, and my pair of ZA3 are driving them just fine via XLR. I actually prefer the Maggies via Class D vs Class A/B. More clarity, and I run them in conjunction with a pair of Zu DW6 Supremes off of a Class A/B amplifier. I use XLR splitters to simultaneously run the ZA3's. The Zu's are louder due to their sensitivity, and the Maggies create some magical fill, it really sounds incredibly good, everyone that has heard this set up was very impressed that two different speakers could sound so good together. But yes, the ZA3's have no issues driving my Maggies.
I have the new fosi zd3 dac and two za3 amps running in mono. I have a pair of sparkos 3602 OA to swap but I am not sure whether I will get the most from the sparkos installed on the balanced circuit of the dac or in the final output za3? Any advice?
@@PassionforSound I installed them in the DAC and there was an incredible soundstage increase. I may move them to the amps tomorrow to see which configuration suits best. As is the sound is warmer and a tad more relaxed but still a bit forward in upper mid for my tastes. I may end up with sparkos in both amps and DAC. Or maybe the Bursun v7 classic in DAC and sparkos in amps. I appreciate your video content and look forward to your review!
Superb review , thank you i have been close to the buy now on the mono block , but now za3 seems the better move . Just wonder what your thoughts are on feeding these amplifiers both in mono mode to bi wire floor standing speakers …would 4 x mono blocs make a significant improvement? You think or an over kill 😊
BI amp i guess is another option , but if im right does not separate left and right channels ….2 x monobloc would be the ideal im thinking left ch and right ch treble part crossover and another 2 to bass part ….
@@Desmodronicus In some cases yes it would be better. But, what is not apparent is that for speaker impedances greater than 3.9 ohms the VA3 does not produce more power in mono mode. (The PBTL mode still produces the same speaker voltage, but has greater current capability) So you really don't gain anything from having 4 over 2. Better and certainly cheaper to have one VA3 for the left speaker and one for the right speaker. The speaker's internal crossover will take care of sorting bass and treble for you.
Not strange. That is the correct way to do it... you use differential circuits to cancel noise and combine the opposing signals into a single ended input right at the input connectors. The rest of the device is single ended until the output when you again create the balanced signal. This does two things for you... First it keeps noise out of your device and Second it reduces failures and heat because only requires half the electronics.
There's actually some truth to both statements here. Normally, a good single ended connection should be just as good as a balanced connection, assuming no ground loops or significant environmental noise sources. However, it does seem like the ZA3 is doing something strange with the RCA input that's nerfing it's quality compared to the XLR as the differences I hear are way greater than I would attribute to a simple summed signal cancelling out environmental noise.
@@PassionforSound Entirely possible... their Gain Switch could be very poorly implemented. Over the last year or so I've caught Fosi out on a number of noteworthy design errors and have communicated with them rather extensively about a couple of them... In particular operating some parts outside their design parameters.
haha before you hear much music there are 20 sets of Ne5532 through the mastering process before it reaches the listener. So magically I am making it better its hilarious
I don't know. I noticed some artifacts in the sound when I was editing, but didn't have time to re-record or attempt to fix it. There were no changes to the sound otherwise.
@@RomanBagdasarov hi thanks for the response. May I know which op amp positions are for gain or output in the v3 mono? And was the op amp upgrade worth it?
@@lolololo359 My mistake. Closest to INPUT terminals is responsible for signal conversion RCA-XLR. Other two are for gain stage. Yes, the installation of opamps is definitely worth it. It has a strong effect on the size of the sound stage (depth, width), on detail, timbre richness and dynamics.
I haven't tried the Classics to add any context here other than to say that I described the sound of each in my review of the V7 range and their performance is consistent across all devices so you can take what's said in that video and apply it to any device.
@@PassionforSound imho, it's better not to mix different opamps (even v7 vivids & classics), cause that leads to problems with sound stage. v3 monos with three pair of Bursons v7 Vivid sound really great. I use them with ProAC DB3 (heavily modified), Gustard R26 and Denafrips Athena preamp.
My experience has been different to yours, I prefer the sound of the V3 mono to that of the ZA3, driving my Zu DWX speakers - I tried both stock. I did have the same experience as you with the XLR and RCA inputs, big difference in favour of the XLR. I subsequently substituted the stock op amps in the V3 mono with the Muses02 (supplied by Fosi as part of a kickstarter deal) and heard an improvement but I'm not convinced it's worth the extra cost if you need to go out and buy them. In Europe the cost of V3 mono x 2 is 300 euro and spending an additional 180 euro on op amps is hard to justify for minimal gains.
6:00 at least they do provide the triggers unlike Schiit & others who think you should get off your arse every time you want to turn the damned things on.
@@PassionforSound How a unit turns on (or how much electricity it consumes when on but not playing) is a major factor for me when choosing and it’s invariably overlooked in reviews & specs. I often wonder why auto signal detection isn’t commonplace because it seems like such an absolute no-brainer, even at whatever the extra cost would be. I know Topping, NAD & Emotiva use it but really wish reviewers would always make a point of including this information. No idea if you routinely include this stuff or not but if you don’t my objective right now is to implore you to pls consider it. I had to return a brand new Mojo2 last year because not only did it need turning on manually (on the unit itself) each time I needed it but it’s auto-standby mode could not be turned off meaning I couldn’t even leave it switched on - I’d seen a bunch of reviews recommending it and not one had even hinted at this super incredibly annoying issue. Cheers!
@anonimushbosh I agree it's important, but it's not a high priority for many people so I can't promise that I'll include that information in all reviews as I have to balance the level of detail and "watchability".
Haha. Yes, I will definitely consider it and it's likely to be something I'll discuss to some degree whenever relevant as opposed to it being a standard discussion point. 🙂🙂
I’m curious how you would rate the ZA3 vs the V3 Monos both with the TI OPA1656 op amps? I upgraded my Monos with the TI op amps and noticed a definite improvement. BTW, based on your V3 Mono review, I added RCA-to-TRS (1/4” phono) adapters to the Monos which allows using RCA inputs that bypass the additional RCA amplification stage (better SQ) and also reduces the gain which allowed me to better level match to my sub amp, which didn’t have enough gain to match with the Monos RCA even in low-gain mode. Thanks!!!
Which XLR cables do you use? Mogami seems to be the most popular brand for XLR but I wasn't impressed with the sound of their RCA cables. Sounded kind of thin to me.
Mogami are popular because of the idea that they're used in studios. That's true, but it doesn't mean they're instantly the best choice and they make many grades of cable. I use Curious Cables, Supra Sword and some Kimber Kables interconnects. The Kimbers are my favourite, but they're all excellent. The lower level Supra cables are great too: ua-cam.com/video/LClS2hiHy94/v-deo.htmlsi=GIWelcvb_dEdZjgq
I don't understand the appeal of this kind of products. Once you include the cost of all the upgrades, then add a preamp + dac/streamers, you can actually get a good class A/B integrated for that kind of money. Imo, you either get a super cheap all in one like the wiim amp or the SMSL if you're on a budget or go for a class AB integrated if you have a bit more money.
Do some specs checking ... I think you'll find these TPA3255 based amplifiers outscore class A/B amps by quite a wide margin... especially in the same price range. For example... A TPA3255 amplifier like the ZA3 can legitimately deliver 220 watts per channel (48v supply, 4 ohm speakers) at very low distortion. A similarly priced A/B amp will be lucky to hit 30 watts per channel with distortion well over 1%. And... FWIW ... the Wiim Amp is also using TPA3255 chips.
In what year are we living in? 1980? You're telling me the best class AB amp i can get for 610$ (the price of his complete fosi system @ 13:14 ) is 30 wpc into 4 ohms with 1% distortion. Thanks for the chuckle... Do some specs checking ... I think you'll find plenty of great integrated amp in that price that are very close in term of power to the Fosi mono but that subjectively sounds much better, with higher build quality and longer warranty. Plus everything is in a single box, which is much more convenient and easier to resell once you're ready to upgrade.
It's also a question of size. Many people want a very compact amp and you can't get power and quality of this level in such a small case without going Class-D. I'm not suggesting these are better than Class-A/AB (I'm also not saying they're not better), but they're definitely smaller without losing sound quality or power.
Hi there Lachlan... it's me again 😅!! Thoughts on ZA3 for use on a pair of passive 8-inch long throw sub-woofers for small room (10' x 13')?? 🤔🤔 Up stream signal for ZA3 coming from older model NAD receiver with dual sub (below 60 - 80 hz) outputs. The receiver handles all x-over filter and level controls. Thank for your time always from Northern California 🎉🎇👍🙌😎
They should work great for that! Unless they're a horribly insensitive speaker driver, the ZA3s will do well. That said, the V3 Monos might be even better with the auto on/off function.
I haven’t heard a good cheap Class D amp since the Tripath amps. TPA-3116 was too bright…TPA-3255 is better but still edgy…Infineon chip amps are too analytical and sharp for me.
If the included opamps are really that mediocre, then calling "rolling" them with other options that cost the same money again for two a "secret weapon" seems silly. At that point you should just've gotten a better amplifier. For the price of two ZA3 plus four expensive opamps, you can get a Hypex based poweramp for example, with 2x250W and better sound quality, and utter stability with zero load dependency. Without changing anything, because it's an inherently superior design in the first place. So yeah, keep "rolling" if that's just fun for you. Just be aware that it's just that, fun with tinkering, but nothing more. It won't magically make it outperform other options for the same overall money.
No. First of all, you only need 2 (two). And you don't need to get the premium ones, a pair of really good opamps costs you $20. Second: Hypex are not superior. And yes, they also use cheap opamps. So you'll still be listening to... Cheap opamps. The NE5532 are only $0.30 and fine for budget gear. But a smart choice if you want to keep the price down and let knowledgeable customers choose their own. This pair of Fosi ZA3's with Sparkos opamps sounds as good or better than my €4500 Danish transistor class A+AB and my 300B tubeamp.
I'm not debating the merits of other amps in this video, just sharing that the ZA3 can be an amazing dual mono setup with lots of range for upgrading the sound to a very respectable level and all in very compact cases.
First ... PFFB stands for Post Filter FeedBack. The circuit feeds the speaker output signals back to the input. It's job is to correct for a peak in the Class D output filters that starts at about 16khz and reaches maximum at about 30khz. Everyone is all bent out of shape over this... but except for truly sloppy design it will be less than 1db within audible range and hardly worth the price of the parts to correct it. This is, in short, yet another audiophile "tempest in a teacup". Second... Op-Amp behaviour is largely determined by the parts surrounding it. The Op-Amps in most of these mini-amps is used as a phase splitter to provide the balanced signal to feed the TPA3255 power amp chip. In most of these products they provide very little gain... 0 in the Fosi products, about 6db in Aiyima. At these low gains the frequency response of just about any Op-Amp runs to megahertz and distortion will be below the threshold of most measuring equipment. That means that any changes in sound you're hearing from your $100.00 Op-Amps is almost certain to be imaginary. The one qualifier on my second point is that most of these mini-amps start out with the NE5532 Op-Amp chips installed. Aside from being dirt cheap ($0.30 each) they are also the most faked chip on Earth. I've seen estimates that as many of half of them are re-branded "something else" chips that are recovered from used equipment. While the logic of counterfeiting a 30 cent part escapes me, testing does show that a large percentage of them are fakes. In these small mini-amps it is very likely the biggest difference in behaviour is derived from getting the NE5532 chips out of there... not from putting something more expensive in. I typically replace them with RC4558 chips, which cost about $0.50 each and, yes that initial swap often does bring better performance.
Sorry dude. All BS. I've tried several opamps in this pair and they all sound different. AD987 sounds even but still like a chip. OracleII 02 sounds lush and full with good 3D space. Sparkos sounds more precise, detailed, spacious and clear. The XLR opamps do not have the same function as the L+R opamps. They don't have to be top notch. According to Fosi
@@Jeep_on_audio Sorry Dude, but bench testing says otherwise. In fact, the differences between the common choices are immeasurably small. Now I don't doubt for one second you had the experiences you claim. But you need to go one step beyond that and ask "Why?" ... Why did you hear what you say you heard? Declarations are not proof. I think you'll find that after a rational examination you will find numerous reasons, none of which have anything to do with electronics or op-amps.
Douglas, you seem to be correcting me on the exact points I made in the opening of the video about PFFB (which I wrote on screen was "Post Filter Feedback") being of minimal importance. I also agree with Jeep that there's a bit more to the op-amps than you've experienced regardless of what measurements you might have taken. The sound of an op-amp comes down to more than its measured distortion or frequency response.
@@PassionforSound As a technician my job depends on my ability to follow what I'm hearing, seeing or feeling to a cause. Is there a bad part? Is it room acoustics? Does it need adjustment? and so on. The thing that I find so disturbing is that people settle for "I hear it" without ever asking *Why* they hear it. If it is a real difference in circuit behaviour you can bet your last dollar it would be tracked down and shown in test results... But in all these years, with all kinds of dodads and gizmos, not one shred of proof that any of it actually makes any real difference at all. I listen to the subjective discussion of things that improve soundstage, depth and a dozen other pet words, but for the life of me I cannot find any part in any piece of equipment that can actually do those things. Nor is there any documentation of how to build a device with "better soundstage", clearer mids, etc. This information simply is not out there. So, yeah, I'm gonna call BS on stuff that just ain't happening. Show me the differences in some credible way and I'm all in for it... but until then I have little choice but to attribute these things to imagination and a general lack of understanding. It especially ticks me off to see companies, marketing ridiculously expensive junk, that exist only to feed upon the generalized technical ignorance in the community and yep, they're going to get called out the most harshly.
I'd recommend chatting to some amp designers about the behaviours and differences between op-amps. There's a reason they either avoid monolithic ones or choose them carefully in high end gear. Maybe look at my interview with Sparkos Labs for more on the topic.
I never tested audio gear in the thousands but with my experience class D amps are more honest then class A and A B amps. There is a reason why monitors that cost in thousands of dollars use class D amplification. I think making a hybrid setup with class D amp and something like schiit frya plus to give you the best of both worlds. really worked hooking up my smsl sh9 to the aune s17 and also my monitors that have a class D amps in each speaker which means i have a mono block lol
@@PassionforSound it would be fun to compare a high end class D mono block to an A B amp. The way I would reference natural tambor of a violin or an acoustic guitar. The smsl sh9 was superior to the aune s17 when it comes down to an honest sound but if you connect the sh9 with with aune pre amp the result you get is absolute music orgasm. Don’t get me wrong the aune over all is superior
@PassionforSound : Well, this review / lesson / story answers my question I was looking for ( I think it was your remark on the Mono amp, at the timeline, where the cage was not high enough to accommodate bigger OpAmps). Thank you solving this so near-term. Another theme I am discovering watching your publications: 😅Audiophiles tune ( nearly ) everything, and I am just getting into this on my journey. Next on my list are the cables ( for XLR and RCA ), then maybe damped speaker stands, and mono blocks such as this one with upgraded OpAmps.
Chinese audio companies have really stepped up their design and manufacturing game in recent years. They don't all look like bland, boring black boxes anymore. They've also put effort into designing better circuits and using quality components. It's also nice that they are pro tinkering and responsive to their customers' feedback. A lot of companies don't want customers to open up their product.
Using this amp as described really does improve the sound in the very area's you discuss...nice job
Thank you for confirming that I've expressed it clearly and accurately!
The sound of your videos just bring my sennheisers to life ❤
That's great to hear!
Great little amp with lots of possibilities. Have to mention however, that tnt reviews reviewed these in mono mode against the zerozone chip mono amps. They favored the overall sound presentation of the zerozones over the za3’s considerably. And they aren’t much more in cost. They can also accept opamp upgrades. Would love to get your impressions on those as well 🙏🏼👍🏼
TNT failed to mention whether the ZA3 was tested with RCA or XLR input. Quite a large omission considering Lachlan's statement on the quality difference between those connections on this specific amp.
That's a HUGE question if it's in doubt. I haven't heard of the zerozones amps. I'd be curious to try them.
@@KXP70 Now that you mention it, you’re right! Thank you for brining that up 🙏🏼
@PassionforSound they are on ebay and aliexpress
I'm running Fosi ZA3 x 2 in mono mode (balanced) into Sony SS-CS5 speakers in my gym. I've also tried them with Klipsch RP600MII speakers. With either speaker setup and proper placement, the amps sound lush, spacious, energetic and vibey, with just enough bass. They also permit channel balancing to fix a suboptimal room shape! I have no desire to further tweak this setup, even though with this hobby I suppose you can never say never.
That's a great point about channel balancing with the ZA3 volume controls!
An extremely good and very interesting review. Thank you.
My pleasure! I'm glad you liked it.
Thank you for taking the time for the detailed information it was very helpful
My pleasure! I'm glad I could help
Amazing video, this makes me excited as a stereo Za3 user who actually doesn't mind how it sounds on RCA, however I'm happy to hear that going XLR and adding another unit as mono only provide further improvement from this point, interesting arguments against the V3 mono and how the different Op Amps can bring tonalities which can add or detract from the overall experience, if only there was a similarly priced DAC to go along with it, with enough body not to sound analytical and thin that someone could use XLR out of, Thank you for the content.
You might be in luck on the DAC front. Stay tuned...
There is a dac like this with the low price tag and the xlr balanced audio plugs
@@JESSEJBaldwinsure, what DAC do you recommend that matches my criteria?
@@aeon7748 Fosi ZD3
For preamp, Schiit came out with the saga 2 last week. They added xlr. I think $279.
So , 2 Za3s as monos and the Schiit Saga as Preamp ? Then add the upgraded op amps?
@@djb5864 yeah, that would get nice kit. I’ve got my saga running 2 Gjallarhorn’s. I think the fosi amps with the sparkos opamps would be nice too.
@@djb5864I'd go with a schiit amp too. A Gjallarhorn is the same price as mono za3, and probably better in everyday use with most speakers. If you need to go to 100db, or have very low sensitivity, I suppose the za3 may do that better.
I don't have a za3, but I'm going to replace a V3 stereo with a Schiit amp after using a 2w Rekkr in a different setup. It sounds much more alive and pleasing.
The most musical amp is the fosi v3 stereo, i had them all and like the normal integraded v3 the most, much more balanced then the v3 mono and za3 !!
Interesting. I haven't tried that one
@@PassionforSound if you look at the price of the fosi v3 you cant believe it, i tryed the 48v 10amp power supply on it and i like the standard 32v better no difference on my speakers ! Its for the money best buy of alltime haha
@@9XThunder If you see this I'd like to know: does "downgrading" the power supply reduce the gain at all? My main complaint about the za3 is the gain is just way too high, but I have the 48v 5a supply and I don't know if that is a factor.
@@lisar3944 what I notice with a 48v power supply is a little more dynamic but also more noise, what you have to do is listen to music not your equipment ;)
The different power supplies alter the maximum power available, but not the gain AFAIK so you'd need to find an alternative way to lower the signal level, I think.
Really informative video. I run Schiit Gjallarhorns in mono in my office setup. But looking for a inexpensive mono-block setup for my living room 2 channel setup. This video was very useful!
I'm so glad I could help!
Quick question, do you really need to replace the XLR socket or just the right channel if running vivids in mono?
I found swapping the op-amp delivered some additional improvement, but the R channel op-amp is the most important in mono mode.
@PassionforSound thanks for sharing your knowledge
@ShannonMcclure-k5d my pleasure
Can you please make a video to compare the difference between upgrading the opamp on the ZA3 only, ZD3 only and both ZA3 and ZD3
Sorry, but I don't have space in schedule for that. My thoughts would be to swap the amp as a first priority because it has more impact there, but do both if you can to get the maximum sound quality.
But what do I do if I need something with a single ended input lol
Buy a different amp... 😉🙂
If running mono, why would you need to replace both the right and left channels in each amp?
You don't if you're running mono - just change the right channel op-amp only
I love the za3 for my lightly driven speakers, especially the Beovox 2200 and 1100, B&Os only audiophile products ;)
I bought the 48V version too because it’s cheap, has XLR input, has sub output, can be mono and powerful even though I have no speakers yet. I use it to power the HFM Susvara headphone but haven’t done any critical listening yet, I have other amps for it. Also, using this as a standby in case I do get a pair of speakers. My friend borrowed it when his amp went for repairs and love it. Looks like he is buying the Mono V3s
Please don't use class D amps for headphones! Where these weren't designed for the high impedance loads that headphones have relative to speakers, it can cause a massive spike in ultrasonic frequencies, which may be a risk for hearing loss even though we cant hear that high. Goldensound done a writeup on it with some measurements that you can google.
- Unless you know this, of course, and you use an impedance adapter. In which case this is important to mention so that people who are unaware won't make the mistake of using a class D speaker amp without one.
Great info - thanks for sharing.
Further to that, the Susvaras simply don't need speaker amps either.
Thanks for another really informative video lachlan. I trust you'll take this as the compliment it's intended to be - I see your approach and presentation quite similar to Tarun (A British Audiophile). Calm, informed and never over the top which is much appreciated. A quick question if I may - if I was going to buy the Burson V7V ops amps for my pair of ZA3's, would it be 2 or 1 per amp? I only use the XLR connections. Thank you
Hi Denis and thanks for the feedback! You can use just one upgraded op-amp in the ZA3, but I found putting one in the R channel and one in the XLR op-amp socket improved the sound even further.
you can get a pair and put 1 in the r channel in both amps to start. Then later, get 2 more and put them in the xlr spots
Just placed 4 LM 4562 chips into the ZA3. LM 4562 : "gift to the audio hobbyist from the industry". I left one subwoofer socket with the original chip...everything else replaced. Also placed one of the LM 4562's in the XLR chip socket.....
One word: Wow ! Only £20 for four LM 4562's. The ZA3 copes very well with these high speed chips...no oscillation. Crystal clear instruments and vocals.
Thanks for sharing your experiences. I'm glad you're enjoying that setup so much.
Whats the point of having additional opamps on an amp? Isnt it like the signal which is comming from DAC has already gone thru opamps and just needs to be amplified without any further processing? How often do you want to hunt the signal thru opamps, on every single stage of the chain?
Also ZA3 and ZD3 have no Headphones jacks which makes the whole chain to the biggest joke ever.
@Joe-Tump op-amps aren't just for adding gain to the signal (i.e. amplification). They are used in almost all audio devices because they control the interface between one device and the next to ensure the right amount of current is available to deliver the signal into the next part of the source chain.
@@PassionforSound But do opams affect the quality of sound on the amp stage too and if so should they? In case where you can roll opamps on DAC and AMP whats the purpose on doing it on both stages?
@Joe-Tump rolling op-amps is all about improving the performance of the device because many devices are built to a budget with lower quality op-amps. They will affect the sound of every device they're in because they're an integral part of the signal path in every device.
Well, this was unexpected.
Thank you for the information, Lachlan!
The more you know...
My pleasure. I'm glad to help
I have some of these coming in to test with the za3 and others. As of now, the main issues with the za3 is it's lack of treble and dullness in revealing systems. Sparkos op amps are an improvement, but I'd still like some more treble. Dual mono is the only way to go with the za3 in my opinion as well. I'm hopeful the burson op amps can bring the treble to the party. I guess, we'll see. So far v3 monos are way better than the za3 at top end performance, and more natural in my set ups. I'd be happy to change my mind with this op amp upgrade, if it is true...
The V7 Vivids really lift the sound of the ZA3s. If the V7s could fit comfortably in the V3 Monos, they'd be my choice, but sadly the case is just that little bit too small. ☹️
Odd I measured the case of the v3 monos, it seems like they should fit in it, just barely, unless their measements listed online are wrong? I assume you tried to fit them in the v3 monos? @@PassionforSound I guess I'll figure it out for myself 😂
@intoitreviews the PCB sits higher than the bottom of the case (probably for ventilation). Another viewer said they could drop the PCB down a rung (there are grooves in the side of the case that hold the PCB) and fit the V7s, but I haven't tried that yet myself.
@@PassionforSound I can confirm they do fit. Barely but they do fit in the v3 monos... try again. Thanks for the shout out when you correct this information for the public 🎉
@@intoitreviews hi I've just got my v3 monos and was wondering if you went for v7 vivid or classic for your mono and what did you think of it?
Hi,
for the mono setup, can I use a subwoofer to each za3 ?
I think you should be able to, but I've never tested that.
How hard is it to remove the circuit board and apply the op amps? Does this require any soldering or disconnecting any wires?
No soldering or any fancy technical knowledge. Just a screwdriver to open the case and some care and patience to align the pins on the op-amps correctly before pushing them in.
interesting... I decided to get the hifiman speaker adapter for headphones and I have now put the mono block amps to good use.... and the amps sound very very good with the harder to drive headphones like the Tungsten and the Hifiman He6 v2.... the op amp swaps sound much more relevant with headphones... plenty of headroom .... great setup for a great price... Fosi is getting ready to release a new ZD3 Dac.. I sure hope they opt for XLR from their new DAC to the V3 mono...
I auditioned the HE6se V2 the other day and found the treble to be too harsh at high volumes, but possibly due to them not being broken-in.
My Tungsten are due any month (year?) now...
. Hey THANKS dixster. The HE Adapter was just what I was looking for (although an adapter cable might work too).
Forget preamp capability, I don't even want a volume control on my headphone power amp. Now I want to try it on the Schiit Gjallarhorn with the Loki mini as a headphone amp combo. Thanks again.
Acid Jazz, Funk & Brass 🔈🔉🔊
I've been thinking about getting that Hifiman speaker adapter for my 300b amp and DCA headphone 🎧. Do you think it will work 🤔 or is it to much ohm power for headphone s?
@@DragnetSound should work fine... you will either need to build or buy a cable to hook it up.. all I did was get a nice speaker cable from Amazon and some connectors... braided the wires and put on the speaker jacks... works really well...
So if you have a decent preamp and got two of ZA3 , can I just set the orange knob to maximum and leave it to that setting forever and ever🤔?
Exactly!
I need to correct you on something. The XLR opamp does not have the same function as the L+R opamps. According to the Fosi team on their forum.
Good news, you only need a pair of Sparkos or Burson, not a quad. I put a pair decent ($7) OracleII 02 in the XLR position. It doesn't matter what you have in the sub positions for 20-150Hz. You can't hear that anyway.
I replaced my 300B and Gato Amp150 for a pair of these. Better sound (just, depending on pref) and less power consumption in these expensive times. You do really need a transparent preamp on these (passive or higher priced). Mine is 4x the price of a ZA3
_"I need to correct you on something. The XLR opamp does not have the same function as the L+R opamps. According to the Fosi team on their forum. "_
Correct ...
The dual op-amp coupled to the XLR inputs is used in differential mode to cancel noise and combine the phase opposite signals from the balanced input into a single ended signal for the rest of the circuit.
The left and right op-amps are used as phase splitters to produce a direct and an inverted signal for the balanced inputs to the TPA3255 power amp chip.
The subwoofer chips are in a low pass configuration, to remove signals above about 200hz from the output signal.
I don't believe I ever claimed the XLR op-amp did the same thing as the others.
Thanks for an excellent review of the ZA3
A question about upgrading the op amps:If I intend to run these as monoblocs then why do I need to buy TWO pairs of op amps ?
Thanks
You don't have to. The only one you HAVE to swap (if you're swapping) is the R channel op-amp. I found that swapping the op-amp up the back near the XLR sockets also helped to improve the sound slightly by improving the processing of the incoming signal.
Wouldn't it be better to swap the l/h channel op amp on mono going to l/h speaker and r/h opamp on mono going to r/h speaker?
Thanks for any advice and for your channel😊@@PassionforSound
I'm not in front of the amps now, but from memory, there's a switch that changes these to mono mode and routes all signals through the right channel only which is why you only change that op-amp if using in mono mode.
I’m confused why you recommend 2 op-amps for mono operation. I’ve had outstanding results replacing only the Left XLR op amp, leaving the differential op amp and removing the rest of the unused op amps on the right and subwoofer channels. Could you explain?
You can definitely use just a single op-amp, but I found swapping both the XLR op-amp and the R channel op-amp gave even better performance. Basically, anywhere the signal is travelling will be improved with a better op-amp in the path.
so what would you rate the Burson Timekeepers out of 10, and what would you rate the Za3 monos with the vivid op amps out of 10?
If the Timekeepers are a 10 (they're the best I've heard in my setup along with the Enleum AMP-23R) then the ZA3 with op-amps is probably a 6. That's not a knock on the ZA3, just a reflection of the vast differences in design and price.
with these fosi i don't know if i should buy this 2 block and a decent streamer or an integrat like a cambridge evo. Which setup is the best ?
I haven't heard the Evo so I can't say. Sorry.
I recently got in my preorder of the V3 mono and I was bummed because I had heard the Burson V7 op amps didn't fit in the chassis. Today I was like f-it let me just open it up and see how it goes because I had some extra V7 Classics. If you look in the mono there are different slots in the chassis. Using the bottom slot they fit perfect! I thought the stock V3 Mono was a little too clinical with my KEF Q150s coming from using my 300b tube amp to drive them. I was missing all those thick mids. Boom those V7 Classics brought these monos right up to the perfect tuning for my taste. They brought the tube-y richness into the vocal midrange with the KEFs. Anyway, hope you have time to test it out with your V3 monos. I know you're a big fan of the V7s.
Ah, so the PCB still fits in the case on the bottom slot? That's exciting!
@@PassionforSound Yep totally! The Classics sound so good in the V3 Mono. I'm definitely not feeling like they are lean anymore. Love your reviews and opinions on everything btw. We have similar taste in sound signatures normally.
@@alenotta so are you running your V3 monos without the front and back plates?
Because I don't see how they would fit with the pcb in a different position in the case 🤔
@KXP70 exactly. I tried to work this out recently and couldn't make it work in any way
What Pre-amp are you using with them? What would you recommend?
I'm using the Burson Voyager, but that's massive overkill. I'd just use the volume control that's built into most modern DACs. It's bit perfect and provides good control.
Hi, great discussion starter. I have a pair of V3 monos and am expecting the zd3 to be delivered soon. Would you prioritise rolling opamps in the zd3 preamp or in the v3 power amps first?
I'd prioritise the amps first. The DAC is less influenced by op-amps.
I don't know what rca cables you were using but it sounds fine through the rca to me, in fact I watch side by side sound blind test where the rca was said to sound better. I get zero background noise running these in mono mode at full volume through the rca's
I used identical RCA and XLR cables (either Supra Sword or Curious cables - I can't remember). The difference was significant on my setup, but there are many factors that could limit the maximum performance of a system and negate the differences between XLR and RCA.
@@PassionforSound I'm new to this kind of thing. Is it true that XLRs normally run at a higher volume? I know they are supposed to have less noise because of how the cables are designed
@@PassionforSound The sound stage through the RCAs seems slightly more layed back imo, which might not be as good for Jazz or some other genres.
@@PassionforSound I love these amps, they are soo good!
@@PassionforSound I have no desire to upgrade the op amps in these. I'm running some custom built Dayton audio reference series speakers and it sounds amazing!
What do you recommend guys for subwoofer op-amp in za3? will sub benefit from better or discreet op-amp, and if yes how does it impact performance? I am using Elac 2070. thanks
That's a great question and one I can't answer because I haven't tried any passive subs.
@@PassionforSound hi thanks, output is for active sub only
Oh, sorry. I thought you meant if you were driving a passive sub with the speaker output.
Unfortunately, my answer is still the same. I would expect that the sound won't be much improved with upgraded op-amps for subs because they're low frequency only, but without testing it, I could be completely wrong.
Interesting...what is the difference in improvement if you replace the xlr opamp with something more affordable, and save the Bursons just for the l/r channel sockets? Most advice I've seen says to leave the xlr and sub out sockets alone and just focus on upgrading the main output opamps, so I'm especially interested in what is behind your rec to upgrade the xlr in, too.
I recently tried a VMV A1 (as a speaker amp - I'm not a headphone listener yet) and while I liked it well enough, it just felt overall "meh" - nice enough but a bit too mellow. When I went back to my za3 I kinda sighed with relief. I'm a little bit embarrassed to like it so much, but as you say, it has an unusually natural sound - especially for class D. I have some Muses 8820's (allegedly very close to the Muses 02) that I want to swap in, but the Bursons are intriguing for sure - not sure I want to spring for 3 or 4 of them, though. If two might be plenty, I might be in!
There's a definite improvement in swapping the XLR socket op-amps as well as the output op-amps. I actually tested this again recently with a channel Patreon member so I'm certain it makes a difference, however I do believe that a lower grade op-amp in the XLR socket would be fine. Something like the MUSES you have would be perfect and then put the Bursons in the outputs only.
@@PassionforSound excellent - thanks so much for the response
What premap do you people suggest? Both for headphones and speakers
You don't need a preamp for headphones. For speakers, it depends a lot on your setup, but most modern DACs offer a perfectly good, bit perfect volume control already.
@@PassionforSoundFiio K7 in preamp mode.
Nice review
I'm glad you liked it
Enjoying this video (and the comments) very much, many thanks. Quick question, is it crucial to use the XLR (Balanced) instead of the RCA (Single-ended) input? Am i losing too much using the RCA input. Note: My DAC only has RCA output.
It really does make a big difference on this unit, I'm afraid. I don't know how they set it up to make the inputs so different, but it's a big shift.
@@PassionforSound got it Lachlan... many thanks for the prompt response...
I use one for my desktop system and it's a great little amp for the $.
I just came back and watched this review -- you may remember me from a recent conversation about op-amp rolling in the comment thread of another video -- and I wonder if your test model of the ZA3 might have had some kind of problem with its RCA input? I'm using the RCA input and it's absolutely dominant over my beloved SMSL AO300.
It might be just that your tastes are different or the synergy between the ZA3 and the rest of your system works well.
@@PassionforSound Also very possible, but switching to balanced would be no big deal: The cash flow is there in a way that it isn't usually. The wrinkle is that I'd need a new DAC since my Arcam irDAC is only unbalanced-RCA out. As you may have seen, I watched your review of the SMSL D6s and I didn't miss that you think the $120 DACs out there are sonically indistinguishable --- but in my use-case (with two Fosi Audio ZA3's -- the SMSL would be the choice because of the balanced outputs, yes? Is there a slightly higher-end DAC (say $300USD or $400USD) that you would recommend instead?
@CinemaDemocratica I'd definitely look at the SMSL RAW-DAC1 if you can. That's incredible value. The RAW-MDA1 is also very good for less money.
@@PassionforSound How about the Topping E70 Velvet -- still go with the SMSL RAW-DAC1 over that one?
@CinemaDemocratica I haven't tried that one so I can't compare. Sorry.
If i would be running only one ZA3 in stereo, via RCA, how many burson op amps would i need? Thank you!!!
You'd want a minimum of two: one for the L channel and one for the R channel. I also found benefits with upgrading the op-amp in the XLR processing socket of the amp. I haven't played around enough to know if the quality of op-amp is crucial there so you could maybe go with something a little cheaper there, but I'm not sure.
Hello, I love your reviews and this one with the op amps swap option among others is awesome. Now
I have a technical question: If i got it right the Fosi Za3 has better quality XLR binding posts than RCA in this particular model. Now if I want to use the Za3 in Stereo Mode the XLR input do I have to swap just the one XLR op amp ? Or the 2 x RCA (right, left) + the XLR … means 3 op amps in total ( as mentioned in Stereo mode) ? Or just 1x the XLR?
I mean this is until I can afford an other Za3 set to have it all in mono mode..
Your top priority in the ZA3 (in stereo mode) are the left and right op-amps. It's also good to swap the XLR op-amp, but slightly less important so you could wait until later or you could use a lower cost/quality op-amp compare to the L/R op-amps.
So glad you're liking the reviews.
@@PassionforSound
Awesome you answered my question! thank you
I was wondering if I had to buy an extra Sparkos (I bought already 2 of them for right & left rca) and it improved the result right away .. and more from RCA now than from the XLR then I thought to make the most of this device so I have to purchase a 3rd Sparkos (my budget is not that extendable) ? So if I place a MUSE02 (way cheaper) in place of the Standard XLR that will work ? I was also worries that if I go with a different kind of op amp it would damage the device or kill the sound !? I have actually 2 x MUSES02
@thomasb.1825 the MUSES02 will be great in the XLR socket and no concerns using a different one in the XLR vs the stereo channels.
@@PassionforSound ? if you are only going to use the XLR connections of the ZA3 (in stereo mode), do you not only have to swap the left and right op-amps of the XLR? No need to also swap the RCA left en right op amps?
@flyindo if you're using it in stereo, you want to prioritise swapping the op-amps closest to the volume control - the left and right ones. The XLR op-amp (the single one at the back) does improve the sound but is less important than the L/R ones.
great review and recommendations...If I were using mono blocs of ZA3s with the OP amp upgrades, would I get better sonics if I used the balanced input or the coax? thanks
Definitely the balanced inputs on those. I'm not sure what they did with the RCA input, but it really degrades the sound on the ZA3.
I bought a pair of the emotiva b2+ about a year ago. These speakers can be bi-amped. I didnt know what bi-amped meant at the time. Now i know and now i have a pair of the V3 monos. Im going to get another pair of V3s and bi-amp the b2+s. Has anyone done this yet?
You don't need another set.... switch the pair you have to stereo mode, use a Y connector on the input to tie L and R channels together ... feed the left channel into the tweeter and the right channel into the woofer.
@Douglas_Blake_579 I have the monos not the stereo one.
@@killebrewje
OOPS ... in that case, yes you would need 4 of them.
(My mistake. The vid is about the VA3 so I made an assumption. Sorry about that.)
Is cool man@@Douglas_Blake_579
I'm yet to play with bi-amping, but would love to hear your experiences if you try it!
I'd love to know how well these drive Magnepan speakers.
Which Magnepan speakers do you have? I’d like to know the results if you’re getting the ZA3. Where are you located?
I have a pair of the Maggie LRS+, and my pair of ZA3 are driving them just fine via XLR. I actually prefer the Maggies via Class D vs Class A/B. More clarity, and I run them in conjunction with a pair of Zu DW6 Supremes off of a Class A/B amplifier. I use XLR splitters to simultaneously run the ZA3's. The Zu's are louder due to their sensitivity, and the Maggies create some magical fill, it really sounds incredibly good, everyone that has heard this set up was very impressed that two different speakers could sound so good together. But yes, the ZA3's have no issues driving my Maggies.
@@BillyKueekSG, I've yet to purchase a pair (it's a medium-term plan).
@@michaelwright1602, that's wonderful! I very much appreciate the comprehensive information.
@@michaelwright1602 thank,you for sharing
How about the topping mono blocs?
I reviewed those just recently: ua-cam.com/video/cdcQ6GGsw3s/v-deo.htmlsi=ATXiuo7wQ893TI6y
I have the new fosi zd3 dac and two za3 amps running in mono. I have a pair of sparkos 3602 OA to swap but I am not sure whether I will get the most from the sparkos installed on the balanced circuit of the dac or in the final output za3? Any advice?
I'm testing the ZD3 for a review now so I'm not sure just yet, but I suspect that the amps might be the better place to use the op-amps.
@@PassionforSound I installed them in the DAC and there was an incredible soundstage increase. I may move them to the amps tomorrow to see which configuration suits best. As is the sound is warmer and a tad more relaxed but still a bit forward in upper mid for my tastes. I may end up with sparkos in both amps and DAC. Or maybe the Bursun v7 classic in DAC and sparkos in amps. I appreciate your video content and look forward to your review!
@JeffreyMann-qq6yj I'm so glad you're enjoying the improved sound and hope you can find the perfect combo.
Superb review , thank you i have been close to the buy now on the mono block , but now za3 seems the better move . Just wonder what your thoughts are on feeding these amplifiers both in mono mode to bi wire floor standing speakers …would 4 x mono blocs make a significant improvement? You think or an over kill 😊
Bi-Wire or Bi-Amp? Two different things.
BI amp i guess is another option , but if im right does not separate left and right channels ….2 x monobloc would be the ideal im thinking left ch and right ch treble part crossover and another 2 to bass part ….
@@Desmodronicus
In some cases yes it would be better. But, what is not apparent is that for speaker impedances greater than 3.9 ohms the VA3 does not produce more power in mono mode. (The PBTL mode still produces the same speaker voltage, but has greater current capability)
So you really don't gain anything from having 4 over 2. Better and certainly cheaper to have one VA3 for the left speaker and one for the right speaker. The speaker's internal crossover will take care of sorting bass and treble for you.
@@Douglas_Blake_579 Thanks Douglas for your advice , i take that , bi wire seems to be very little used
@@Desmodronicus
Not really ... If anything it is over used since it provides no real advantage.
I find it interesting that the XLR input sounds better. It's an unbalanced amp using an op amp to convert the XLR input. Strange
Not strange. That is the correct way to do it... you use differential circuits to cancel noise and combine the opposing signals into a single ended input right at the input connectors. The rest of the device is single ended until the output when you again create the balanced signal. This does two things for you... First it keeps noise out of your device and Second it reduces failures and heat because only requires half the electronics.
There's actually some truth to both statements here. Normally, a good single ended connection should be just as good as a balanced connection, assuming no ground loops or significant environmental noise sources.
However, it does seem like the ZA3 is doing something strange with the RCA input that's nerfing it's quality compared to the XLR as the differences I hear are way greater than I would attribute to a simple summed signal cancelling out environmental noise.
@@PassionforSound
Entirely possible... their Gain Switch could be very poorly implemented.
Over the last year or so I've caught Fosi out on a number of noteworthy design errors and have communicated with them rather extensively about a couple of them... In particular operating some parts outside their design parameters.
Do I need BURSON AUDIO V7 VIVID PRO Dual OPA or BURSON AUDIO V7 VIVID PRO Single OPA ? :/
The Fosi gear uses dual chips
Thanks for sharing!
The trigger cable is included in the ZD3?
I don't think so, but don't quote me on that one.
@@PassionforSound The cable is included in the ZD3, not ZA3. They sell ZD3+ZA3 as a package deal.
Thanks for confirming!
haha before you hear much music there are 20 sets of Ne5532 through the mastering process before it reaches the listener. So magically I am making it better its hilarious
What is a trustworthy source for the TI opamps?
Mouser
Yep. Any of the major online electrical parts stores like Mouser, RS Online, etc.
Ok , thanks. I am in Australia so will see what is easiest out of those
What happened to your microphone? Did something force you to over use noise supression or something?
I don't know. I noticed some artifacts in the sound when I was editing, but didn't have time to re-record or attempt to fix it. There were no changes to the sound otherwise.
@@PassionforSound Interesting, it sounds really thin and glitchy like talking over a pair of true wireless earphones
Yes, I noticed that too. Perhaps there was some cellular noise that got into the system if I put my phone in the wrong place during recording.
Interesting,I just watched a video earlier today that concluded the sparko was the superior op amp.
Which Sparkos? They have the 2590 which I believe IS better than the V7s, but I'd take the V7s over the Sparkos 3602.
@@PassionforSound it was the 3602
2590 is cheaper.
Which channel reached that conclusion? The 2590 might be cheaper if purchased without the 8-pin adapter, but it's definitely the more advanced op-amp.
@@PassionforSound skunkie designs electronics
@alanrobinson2229 I'll take a watch
Hi thanks so much for the review! Can I ask if you have tried v7 classic in the amp? Or maybe a mix of v7 classic and vivd
I use v7 classic & vivd in gain stage and v7 vivid in output stage with my v3 monos. But I had to file down some aluminum from opamps to fit v3 monos.
@@RomanBagdasarov hi thanks for the response. May I know which op amp positions are for gain or output in the v3 mono? And was the op amp upgrade worth it?
@@lolololo359 My mistake. Closest to INPUT terminals is responsible for signal conversion RCA-XLR. Other two are for gain stage.
Yes, the installation of opamps is definitely worth it. It has a strong effect on the size of the sound stage (depth, width), on detail, timbre richness and dynamics.
I haven't tried the Classics to add any context here other than to say that I described the sound of each in my review of the V7 range and their performance is consistent across all devices so you can take what's said in that video and apply it to any device.
@@PassionforSound imho, it's better not to mix different opamps (even v7 vivids & classics), cause that leads to problems with sound stage. v3 monos with three pair of Bursons v7 Vivid sound really great. I use them with ProAC DB3 (heavily modified), Gustard R26 and Denafrips Athena preamp.
Have you tried the Classics?
No. I suspect they might be a little too smooth, but if that's the sound you're after the overall quality will be exceptional.
@@PassionforSound no never heard either yet. I buy Sparkos
The Vivids are clean and crisp, the Classics are warmer and smoother so it depends on your tastes.
My experience has been different to yours, I prefer the sound of the V3 mono to that of the ZA3, driving my Zu DWX speakers - I tried both stock. I did have the same experience as you with the XLR and RCA inputs, big difference in favour of the XLR.
I subsequently substituted the stock op amps in the V3 mono with the Muses02 (supplied by Fosi as part of a kickstarter deal) and heard an improvement but I'm not convinced it's worth the extra cost if you need to go out and buy them. In Europe the cost of V3 mono x 2 is 300 euro and spending an additional 180 euro on op amps is hard to justify for minimal gains.
Thanks for sharing your experiences. I wonder if it's a speaker synergy thing? Or maybe just different preferences.
Amps without pffb seem to have flatter response with 4 ohm loads rather than 8 ohm loads
True
Don't all class D amps have PFFB?
Nope ... some of the "high end" ones do but most of the consumer grade "chip amps" do not.
It's becoming more common on entry level gear too like the V3 Monos, but it's importance is a little overblown, I think.
@@PassionforSound
More than 'a little".
6:00 at least they do provide the triggers unlike Schiit & others who think you should get off your arse every time you want to turn the damned things on.
That's true
@@PassionforSound How a unit turns on (or how much electricity it consumes when on but not playing) is a major factor for me when choosing and it’s invariably overlooked in reviews & specs.
I often wonder why auto signal detection isn’t commonplace because it seems like such an absolute no-brainer, even at whatever the extra cost would be. I know Topping, NAD & Emotiva use it but really wish reviewers would always make a point of including this information. No idea if you routinely include this stuff or not but if you don’t my objective right now is to implore you to pls consider it.
I had to return a brand new Mojo2 last year because not only did it need turning on manually (on the unit itself) each time I needed it but it’s auto-standby mode could not be turned off meaning I couldn’t even leave it switched on - I’d seen a bunch of reviews recommending it and not one had even hinted at this super incredibly annoying issue. Cheers!
@anonimushbosh I agree it's important, but it's not a high priority for many people so I can't promise that I'll include that information in all reviews as I have to balance the level of detail and "watchability".
@@PassionforSound I said consider… so I’ll take that as a yes then - with thanks! Cheers
Haha. Yes, I will definitely consider it and it's likely to be something I'll discuss to some degree whenever relevant as opposed to it being a standard discussion point. 🙂🙂
What they like as monos with the power hungry Magnepans… anyone tried?
Someone in the comments is using them with Magnepans.
@@PassionforSound Found the comments, thanks.
If you use this in mono mode and have a pair of them, can you still use the subwoofer output on BOTH of them?
Seriously awesome amp.
That's a great question that I haven't looked into, but I suspect so given that the sub output is a mono output already
I’m curious how you would rate the ZA3 vs the V3 Monos both with the TI OPA1656 op amps? I upgraded my Monos with the TI op amps and noticed a definite improvement.
BTW, based on your V3 Mono review, I added RCA-to-TRS (1/4” phono) adapters to the Monos which allows using RCA inputs that bypass the additional RCA amplification stage (better SQ) and also reduces the gain which allowed me to better level match to my sub amp, which didn’t have enough gain to match with the Monos RCA even in low-gain mode. Thanks!!!
Great trick! Good thinking.
I haven't tried the ZA3 with the 1656 op-amps, but I i suspect the differences would be minimal once those are installed.
Which XLR cables do you use? Mogami seems to be the most popular brand for XLR but I wasn't impressed with the sound of their RCA cables. Sounded kind of thin to me.
Mogami are popular because of the idea that they're used in studios. That's true, but it doesn't mean they're instantly the best choice and they make many grades of cable.
I use Curious Cables, Supra Sword and some Kimber Kables interconnects. The Kimbers are my favourite, but they're all excellent. The lower level Supra cables are great too: ua-cam.com/video/LClS2hiHy94/v-deo.htmlsi=GIWelcvb_dEdZjgq
@@PassionforSound thank's for the info
I don't understand the appeal of this kind of products. Once you include the cost of all the upgrades, then add a preamp + dac/streamers, you can actually get a good class A/B integrated for that kind of money. Imo, you either get a super cheap all in one like the wiim amp or the SMSL if you're on a budget or go for a class AB integrated if you have a bit more money.
Do some specs checking ... I think you'll find these TPA3255 based amplifiers outscore class A/B amps by quite a wide margin... especially in the same price range.
For example... A TPA3255 amplifier like the ZA3 can legitimately deliver 220 watts per channel (48v supply, 4 ohm speakers) at very low distortion. A similarly priced A/B amp will be lucky to hit 30 watts per channel with distortion well over 1%.
And... FWIW ... the Wiim Amp is also using TPA3255 chips.
In what year are we living in? 1980? You're telling me the best class AB amp i can get for 610$ (the price of his complete fosi system @ 13:14 ) is 30 wpc into 4 ohms with 1% distortion. Thanks for the chuckle...
Do some specs checking ... I think you'll find plenty of great integrated amp in that price that are very close in term of power to the Fosi mono but that subjectively sounds much better, with higher build quality and longer warranty. Plus everything is in a single box, which is much more convenient and easier to resell once you're ready to upgrade.
@@orthosympa6993
That's entirely up to you ...
The ZA3 retails for $199 in Canada ... how much A/B you gonna get for that?
It's also a question of size. Many people want a very compact amp and you can't get power and quality of this level in such a small case without going Class-D.
I'm not suggesting these are better than Class-A/AB (I'm also not saying they're not better), but they're definitely smaller without losing sound quality or power.
@@PassionforSound also, you dont have to buy it all at once, while still enjoying some tunes
Hi there Lachlan... it's me again 😅!! Thoughts on ZA3 for use on a pair of passive 8-inch long throw sub-woofers for small room (10' x 13')?? 🤔🤔 Up stream signal for ZA3 coming from older model NAD receiver with dual sub (below 60 - 80 hz) outputs. The receiver handles all x-over filter and level controls. Thank for your time always from Northern California 🎉🎇👍🙌😎
They should work great for that! Unless they're a horribly insensitive speaker driver, the ZA3s will do well. That said, the V3 Monos might be even better with the auto on/off function.
easier buy MC catrige with turntable :)
I haven’t heard a good cheap Class D amp since the Tripath amps. TPA-3116 was too bright…TPA-3255 is better but still edgy…Infineon chip amps are too analytical and sharp for me.
I've been really impressed with some of the recent ones (for the price). It might be worth revisiting if you're interested
If the included opamps are really that mediocre, then calling "rolling" them with other options that cost the same money again for two a "secret weapon" seems silly.
At that point you should just've gotten a better amplifier.
For the price of two ZA3 plus four expensive opamps, you can get a Hypex based poweramp for example, with 2x250W and better sound quality, and utter stability with zero load dependency. Without changing anything, because it's an inherently superior design in the first place.
So yeah, keep "rolling" if that's just fun for you. Just be aware that it's just that, fun with tinkering, but nothing more. It won't magically make it outperform other options for the same overall money.
No. First of all, you only need 2 (two). And you don't need to get the premium ones, a pair of really good opamps costs you $20.
Second: Hypex are not superior. And yes, they also use cheap opamps. So you'll still be listening to... Cheap opamps.
The NE5532 are only $0.30 and fine for budget gear. But a smart choice if you want to keep the price down and let knowledgeable customers choose their own.
This pair of Fosi ZA3's with Sparkos opamps sounds as good or better than my €4500 Danish transistor class A+AB and my 300B tubeamp.
I'm not debating the merits of other amps in this video, just sharing that the ZA3 can be an amazing dual mono setup with lots of range for upgrading the sound to a very respectable level and all in very compact cases.
First ... PFFB stands for Post Filter FeedBack. The circuit feeds the speaker output signals back to the input. It's job is to correct for a peak in the Class D output filters that starts at about 16khz and reaches maximum at about 30khz. Everyone is all bent out of shape over this... but except for truly sloppy design it will be less than 1db within audible range and hardly worth the price of the parts to correct it. This is, in short, yet another audiophile "tempest in a teacup".
Second... Op-Amp behaviour is largely determined by the parts surrounding it. The Op-Amps in most of these mini-amps is used as a phase splitter to provide the balanced signal to feed the TPA3255 power amp chip. In most of these products they provide very little gain... 0 in the Fosi products, about 6db in Aiyima. At these low gains the frequency response of just about any Op-Amp runs to megahertz and distortion will be below the threshold of most measuring equipment. That means that any changes in sound you're hearing from your $100.00 Op-Amps is almost certain to be imaginary.
The one qualifier on my second point is that most of these mini-amps start out with the NE5532 Op-Amp chips installed. Aside from being dirt cheap ($0.30 each) they are also the most faked chip on Earth. I've seen estimates that as many of half of them are re-branded "something else" chips that are recovered from used equipment. While the logic of counterfeiting a 30 cent part escapes me, testing does show that a large percentage of them are fakes. In these small mini-amps it is very likely the biggest difference in behaviour is derived from getting the NE5532 chips out of there... not from putting something more expensive in. I typically replace them with RC4558 chips, which cost about $0.50 each and, yes that initial swap often does bring better performance.
Sorry dude. All BS. I've tried several opamps in this pair and they all sound different. AD987 sounds even but still like a chip. OracleII 02 sounds lush and full with good 3D space.
Sparkos sounds more precise, detailed, spacious and clear.
The XLR opamps do not have the same function as the L+R opamps. They don't have to be top notch. According to Fosi
@@Jeep_on_audio
Sorry Dude, but bench testing says otherwise. In fact, the differences between the common choices are immeasurably small.
Now I don't doubt for one second you had the experiences you claim. But you need to go one step beyond that and ask "Why?" ... Why did you hear what you say you heard?
Declarations are not proof.
I think you'll find that after a rational examination you will find numerous reasons, none of which have anything to do with electronics or op-amps.
Douglas, you seem to be correcting me on the exact points I made in the opening of the video about PFFB (which I wrote on screen was "Post Filter Feedback") being of minimal importance.
I also agree with Jeep that there's a bit more to the op-amps than you've experienced regardless of what measurements you might have taken. The sound of an op-amp comes down to more than its measured distortion or frequency response.
@@PassionforSound
As a technician my job depends on my ability to follow what I'm hearing, seeing or feeling to a cause. Is there a bad part? Is it room acoustics? Does it need adjustment? and so on.
The thing that I find so disturbing is that people settle for "I hear it" without ever asking *Why* they hear it. If it is a real difference in circuit behaviour you can bet your last dollar it would be tracked down and shown in test results... But in all these years, with all kinds of dodads and gizmos, not one shred of proof that any of it actually makes any real difference at all.
I listen to the subjective discussion of things that improve soundstage, depth and a dozen other pet words, but for the life of me I cannot find any part in any piece of equipment that can actually do those things. Nor is there any documentation of how to build a device with "better soundstage", clearer mids, etc. This information simply is not out there.
So, yeah, I'm gonna call BS on stuff that just ain't happening. Show me the differences in some credible way and I'm all in for it... but until then I have little choice but to attribute these things to imagination and a general lack of understanding.
It especially ticks me off to see companies, marketing ridiculously expensive junk, that exist only to feed upon the generalized technical ignorance in the community and yep, they're going to get called out the most harshly.
I'd recommend chatting to some amp designers about the behaviours and differences between op-amps. There's a reason they either avoid monolithic ones or choose them carefully in high end gear.
Maybe look at my interview with Sparkos Labs for more on the topic.
RCA input s on these are horrible. I wish I would have heard this before buying 2 of ZA3s. No power at all.
It's not a lack of power, but I agree that they don't sound very good.
A miracle weapon for € 90 each?. 🤦😂😂😂
A miracle weapon is a good preamplifier, why do you always forget that? 🤔
I never tested audio gear in the thousands but with my experience class D amps are more honest then class A and A B amps. There is a reason why monitors that cost in thousands of dollars use class D amplification. I think making a hybrid setup with class D amp and something like schiit frya plus to give you the best of both worlds. really worked hooking up my smsl sh9 to the aune s17 and also my monitors that have a class D amps in each speaker which means i have a mono block lol
I haven't gone high enough up the tree yet to compare truly high end class-D with high end class-A/AB but hope to in the future.
@@PassionforSound it would be fun to compare a high end class D mono block to an A B amp. The way I would reference natural tambor of a violin or an acoustic guitar. The smsl sh9 was superior to the aune s17 when it comes down to an honest sound but if you connect the sh9 with with aune pre amp the result you get is absolute music orgasm. Don’t get me wrong the aune over all is superior
@PassionforSound : Well, this review / lesson / story answers my question I was looking for ( I think it was your remark on the Mono amp, at the timeline, where the cage was not high enough to accommodate bigger OpAmps). Thank you solving this so near-term.
Another theme I am discovering watching your publications: 😅Audiophiles tune ( nearly ) everything, and I am just getting into this on my journey. Next on my list are the cables ( for XLR and RCA ), then maybe damped speaker stands, and mono blocks such as this one with upgraded OpAmps.
Someone has posted that the V3 Monos can potentially fit the V7 Vivids, but I need to test that. I'm so glad you're enjoying the audio journey so far.