yeah, it looks like a winner! But I would not mind upgrading some of these cheap Chi-Fi preamps as well. this one really misses another set of preout for subwoofers or bi-amping.
@@00LongLong00 The MP offers so many tube and capacitor rolling options.... I'd start with the v-cap ODAM option and upgrade the stock tubes to get a neutral & holographic presentation. Mundorf SGO Evo supreme caps give a more saturated tonal colour... And that's just scratching the surface . I keep a DENAFRIPS Hestia12th on hand for a baseline reference. The MP is just more! 🎵🎶😉🎶🎵
Mine arrived quick. Ordered the premium version. Small amount of local tax. Sound out of box was thin. See after burn in. Very nice build quality. And my unit reads Goldmund!
@@sean_heisler Still think it is thin (front/back depth) sounding compared to tubes. Typical of S/S IMO. Serves its purpose in my casual listening S/S system.
@@errcl65 Thanks! I have both tube and SS preamps as well and I hear you. Once you have tubes in your system and you go back to solid state the thinner, very contrasty quality becomes quite noticeable. Did you see his review of the Accuphase clone? That sounds like it might be a little fuller sounding. You may be asking why I am looking at preamps when I already have two. I'm obsessed.
Yes. An excellent surprise. Interesting. I am looking forward to your upcoming videos/thoughts on/aboutthose products you mentioned including the SMSL DO 200 Pro.
@@k4syxyou will, of course, compare the DO 200 Pro (as a preamp DAC) with the other AliExpress preamps! This is in addition to reviewing the SMSL purely as a DAC. Thanks!
Try the Weilliang MBL 6010c clone... I got mine fron ebay at about $400 and then changed op amps for Sparkos and sounds great... Has both RCA and XLR inputs and outputs and a remote control as well..
It looks like there are 14 op amps inside the 6010. Did you replace all of them? Because at roughly $80 each, this would take the final product well into the $1000+ range
Hi, the Mundorff Capacitors actually seem to be real. And the popping sound is normal with "old-style" devices without delay-relais :) All the Best, Sebastian
Ive come across so many interesting clone amp boards on ebay, ive seen many folks assemble them and do videos on their quality. Id love to see someone who has the OG amp it was cloned from compare it DIRECTLY and get a realistic idea as to how close it might sound. Would love to see that.
@@AllboroLCD I think that's hard to see as diy folk rarely buy expensive branded amps, and the other way around: people buying very expensive audio stuff are not diyers so they won't usually even peek inside the cable they bought... :(
@@k4syx Totally understood. Theres a Jeff Rowland LM3886 amp & Pass Labs Aleph that most pique my curiosity. I mean if the circuits are 100% correct and enough power fed, The margin of difference will break down to the quality of components is my best guesstimate.
@@AllboroLCD exactly. Plus, pairing of the components - how well can you and will you match everything inside. All in all, these all are electronic circuits, no magic components there.
Very good build for the price...for instance the main R-core transformers each have two 15V 15VA windings, and are available on Ali for around $20 each...and there are two of them. Some other versions of the JC2 (including one that sells for $450) have much lower spec 7.5VA transformers which sell for only $9 each. Looking at all the JC2 versions, this appears to be the one to get. It may be tempting to buy the most expensive version, thinking that it will be the best built and best sounding, but this probably does not apply here. In the product description it erroneously says 'conrad-johnson' instead of "Mark Levinson'
Yes I got it based on the photos: they got my attention with such a nice and planned build. I just had to try it though I had no need for one more preamp ;) And yes they mention Conrad Johnson, looks like a paste from some other desc.
Thanks. This one is better, though its _more_ expensive and lacks XLR outputs. This one is like 2x more expensive, the first one is excellent but two times cheaper. Both of them punch way above price level!
Set bias, finished rewiring with Mogami Neglex 2534. Used Stabliant 22A on 3 pin header on the relay gain board. All have positive audio improvements. I think all the pots need to be replaced with better ones which hold their setting. A lot of drift even in bias in idle. Same for psu rails. Sonically, very clean, very fast. Still early stages of critical listening.
@@errcl65 thanks for sharing, I'm happy it's sorted out. Yes, clean and fast are a very good words to describe it. It's very airy and transparent. I wonder about these Mundorfs, I will reach to them in Germany to ask if there are real ones with holograms. The ones I always bought locally (100prc.originals) never had anything like that regardless of the series (up to Evo silver in oil at least)
@@errcl65 oh and thanks for the tip on Mogami, I was wondering what should I use for some rewiring in other clones and you made me realize that I have some Mogami, Sommer and Canare unused in one of my "daddy's stuff, don't touch" drawers :)
Internally wire with same stuff you use for interconnects. And only shield ground the source end. Also from factory, input and output wires tie-wrapped together. Not a good thing...
@@errcl65 for ICs I usually used QED, I think these are to thick to be used here internally, but, again, that's also something from the same drawer. Ahhh I forgot, I also have some silver plated solid core OCC copper in Teflon coating! Will have to look there tomorrow =)
I enjoyed this review. i'm currently looking at the Sugden A21 or FM 300A and some of the Pass Labs clone. appreciate your input on these. thanks in advance.
Thanks for the look! Regarding the smaller blue transformer. It is NOT the primery reason of it existence to give any sound quality improvements. This is a more normal and reqirued implementation today when you have remote and standby. Legislations requrie that power consumption have to be lower at stand by. So developers has implemented a smaller transformer with a relay (the light blue one) that cut out the two bigger transformers but consumes only small power that is needed to keep the IR alive to be able to switch it on by remote when it is in stand by. In the past without the little dark blue transformer then the unit needed to keep the power on the much bigger main transformers in stand by. When they draw more in stand by than a smaller transformer that gives us higher wattage drawn in stand by. That is the primary reason for its existens, and it is nice to see that they comply to the power regulations in stand by.
Years ago I was part of a listening panel during R&D of a stand alone phono stage...which needed maybe a 10VA transformer. One day we listened to the identical stage hooked up to different transformers...all the way from a 30VA to a 250VA. And every time a larger VA transformer was hooked up, the sound got better. Later on we tried a 500VA transformer and did not feel that the significant extra cost was worth it over the 250VA one. But the gap between a 50VA and a 250VA was huge.
@@rontoolsie Yes, same here. I got a very nice RIAA and upgraded to more than twice as big transformer (R-core). But to be honest I did not hear any difference after the upgrade. The sonic hearing memory is short and it were not any fast A and B comparison.. But I guess it were not worse anyway. 😉
@@SartajAnand No idea honestly, but look at the characteristic four white mundorf capacitors on the photos, I can check if that's the right device for you if you'll give some links here
Hi ,I would like to connect this Preamp to the 2 stereo power amps to have "vertical bi-amping" . One channel of the stereo amp would power treble and second channel for powering the base speaker of the same loud speaker. How to do that ?
So you basically need something like RCA splitter to have two RCA cables coming from preamp to both inputs on each power amp. You can get splitters like that for like 1USD on Ali or source them locally, they are quite popular.
@@k4syx Although electronically this would work, you should be careful if your power amps have low input impedances, since biamping them effectively reduces the load the preamp sees by 50%. For power amps with high input impedances than even cutting it in two still gives a high enough load. But amps with an input impedance of under 20kOhms may start to show roll-off of high frequencies and increased sensitivity to the length of the interconnects.
I got something like that: SE1: Set default volume value for power on. SE2: Set maximum volume" SE3: Set the resistance change curve. SE4: Set encoder rotation direction. SE5: Set the backlight value. SE6: Set volume mode to.
A few years ago I had a problem with the same ladder attenuator kit. It had a noise bump on one spot and also ground was shared on audio & control circuit...
@@k4syx If you don't have a problem don't worry, it was VERY noticeable! I guess they issued an update in the mean time... I had to cut some of gnd trace on attenuator pcb
@k4syx power rails +/-15 messed. Cheap Potentiometer and right next to 67C heat sinks. Quiet now. Need to check bias, but no docs. I adjusted so both sides read the same 0.45V for now. They were not the same initially. One was .35V.
@@omadasmtp543 I think it may be possible to get one by contacting the store, these are schematics that are floating over the web but the thing is to know which one they have used. Some of the stores even post diagrams as a part of description of the product so you can take a look before you buy anything
@@martinhalmo5678 dead silent.. when I was doing the burn in, I've done it with low input level (lowered via DAC vol control) and high gain on preamp to have it more stressed. Still, dead silent.
hello my friend. I asked Mudorf whether the capacitors with holograms were real. Yes, they are real!! Here is the text from Mundorf himself: Good afternoon Mr. Schwarzbeck The MCaps in the photos are real, no question. We supply Chinese manufacturers directly from orders worth €5,000 or more. Our distributor is responsible for this, and he also delivered the MCaps shown to the manufacturer. Best regards, Norbert Mundorf Senior Global Sales & Marketing Officer
@@christian_schwarzbeck Hi Christian! Thanks for the info, we've actually discussed this news in the comments as it was mentioned that you've actually reached to Mundorf and they confirmed it's real. That's great news actually, excellent surprise!
Good morning...Ihave probleme. iwant to adjust the 0 mv. whitch test points can i use ihave a picture for the 15 volts and 0.440mv from the seller but the 0mv are missing (the middle volts)
AFAIK there are only two reference points, Errcl here had done that, look in comments below and ask for his experience. I've added "short" info to the description of the video when he shared what needs to be done.
Another great video mate, would be nice if you could review some good value tube clones. Placed an order for a balanced Dart 108 & currently looking out for a balanced tube pre to go as I’m running a 6m long interconnect. Looking forward thks.
MP701 has already gotten numerous reviews & well received. However it’s not a truly balanced circuitry & I’m not courageous enough to go down that rabbit hole of infinite variabilities thus some chi-fi clones would be more ideal for tight budget. Something in the likes of CAT SL1 in my opinion, heard a genuine one decades back & it sounded really amazing but non XLR though or something you’d recommend. The tube community is still strong, it’s the chi-fi community that needs more awareness.
@@k4syx cracking in the HF and some hiss. The right is dead silent. Unit was dead silent when I first go it 2 weeks ago. I will stick on the bench and scope the outputs today with grounded inputs.
@k4syx power rail adjustment. A noisy pot was messing -15v. I didn't test until i tweaked bias. I don't think it was misajusted bias cause random static. May replace this 4 pots when I pooge in better signal cables.
The only thing the two channels electrically share is a common power cord. After that, it is effectively two completely separate mono preamps, housed inside the same chassis. Most preamps have only a single power transformer with the filter caps shared by both channels, which are put on a single PCB. Years ago, I had a home demo of a 4 box Krell preamp with each channel having separate boxes with their own separate power supplies. It was pretty good too.
Hi very interesting review indeed as usual I think that the difference in details you perceive could be coming from the different attenuator type used in the two preamps The blue pots are quite fine but nothing beats a network of good quality resistors I do not know how many sections the Accuphase volume control has But i would try a stepped attenuator in place of the rotary potentiometer A 4 sections stepped attenuator however comes very expensive The very good ones cost more than the preamp under test If you say that the 3D effect is better on the Accuphase for me this is very very telling Only the very best equipment provide a great 3D soundstage Is the evidence of amazing linearity even at low signal levels In conclusion my own guess is that the Accuphase is the better preamp circuit of the two Do you know if the Accuphase is also availabe in kit form maybe ? Thank you very much indeed Kindest regards gino
I haven't seen accu in diy kit :( Accu clone is very 3d like, and this one seems like more transparent (but this doesnt mean that accu is not transparent - these are details that are apparent when switching between two of them. I am really curious about pairing these preamps - all three of them - with E-405 clone thats on its way to me)
@@k4syx hi thank you very much for your kind and valuable reply I am pretty sure that a weak point in the Accuphase is its volume control Often the fact that is branded Alps does not ensure that it is a genuine part I did some test Even a cheap series attenuator was exceptional for detail I can assure you that was a enlightning experience The Accuphase circuit should be quite close to perfection For me the ability to render a great 3D soundstage is everything There are specific tracks to evaluate that but i am sure you know better than me In the end i am pretty sure that both must be fantastic Kind regards, gino
Hi Tom (Tomász?) - many many thanks for reviewing this preamp! I think I am in serious danger of ordering it! 😂 Your recommendation of the Transaudio D5 Pro was exactly what I was looking for and I suspect that pairing it with this preamp will satisfy my input needs. I never listen to headphones these days anyway so the lack of a second output for the headphone amp doesn't hurt. I love that it should be very detailed, dynamic, airy with deep bass. I trust your judgement, especially after my experience with the D5 Pro. You may remember that I will be replacing a 38 year old exposure XI+XII Preamp combination which is *_still_* *very good* but perhaps has been eclipsed by other designs and newer components. One question - do you have a suggestion for removing the silly gold-coloured "Coldmund" name plate? Warm air from a hairdryer perhaps? All black would suit my system aesthetics better. Greetings from rural Switzerland to Poland, All the best, Rob
@@k4syx Hi! I have taken the plunge and bought one, it should arrive in about 2 weeks. I can't wait! My first new preamp in 38 years! Thanks for the tip about isopropyl alcohol! What's your burn-in process for a preamp? All the best, Rob in Switzerland
@@RobWhittlestone Hi! It usually takes about two weeks in a row. One week should be probably enough but since I don't always have the time to listen to the device it usually stretches a bit ;) I leave everything on playing some test tracks with speakers facing each other and with one out of phase to make them quieter. I've made a video on speaker burn in, that's basically the same. I also have dummy 8ohm loads for amps, but these do not change with freq like real speakers do so I'm not using them now
@@k4syx Hi Greg - UPDATE: I received the device *but after only a few weeks' operation the device failed on one channel* during an evening with friends. It was feeding my Transaudio D5 Pro which went into self-protection mode. This happens if there is DC or very low frequency AC (
@@k4syxHi Tom, I bought it and was happy with it for about 3 weeks. Unfortunately, after 3 weeks it failed on the right hand channel with low signal output, loud clicks and pops and bangs, hissing and rustling sounds. I contacted the seller and they offered to pay for a repair or return it and they send me a new one. I have now shipped it to China and am awaiting further communication with the seller. They asked for a video of the defect which I was able to supply as a compressed MP4 file after many attempts trying to send links to the original MOV files. For the moment I remain neutral about the experience and have decided to trust the seller. I hope this was the right decision. Rightly they should cover the return costs. Let's see if they do. All the best, Rob in Switzerland
Got the preamp today. unfortunately not usable. There is a lot of hissing and humming from the speakers. After the FM 300, the next disappointment. The FM had similar problems. I've tried everything, including galvanic isolation. I am China clone cured.
@@dieterloebel2459 have you tried checking your power grid for DC component and /or using EMI filter for the power line? Cause it can't be just pure coincidence that you have two completely different devices in a row having exactly the same problem, not experienced by other folk? I think that's something that I would put on my list of things to check :)
@@dieterloebel2459 Now thats even more weird. Any chance to get one of these to your friend in other part of the town or to your workplace to check it out in completely different power grid segment? I really really strongly believe you have EMI interference in power line - Ive used to live near workshop with powered tools, and one the guys were powering angle grinders a lot of eqipement was going nuts. Same thing happens sometime if you have old or slightly damaged fridge, when its starting cooling it may feed emi back to the grid
@@k4syx I already had some devices here. Not a single one had such a problem. The clone is very sensitive there. I actually didn't want to buy a clone after the FM300. Now unfortunately it has hit me again. I already had 2 power amplifiers, 2 preamplifiers and 2 integrated amplifiers here in the apartment. I never had such problems as with the clones. It's a shame that the somehow have a problem with the potential/ground.
@@dieterloebel2459 That's really really bad luck. One blind shot more: have you tried rotating power plug in the wall socket to get L and N the other way around? I know schuko will allow you to do that
Yeah they are using ideas with patents expired and since it has been a few years they can use better parts and sometime improve original designs. Kinda like business version of diyaudio forums ;)
@@errcl65 I have to contact Mundorf on that. Haven't seen holograms on these earlier (and I do buy them locally) and there are other small differences. But maybe I missed something that happened during last year or so. Why do you think these are real? Have you seen them being sold somewhere in Europe?
Goldmund is a expensive brand, but it doesnt mean that the components inside (resistors, capacitors, all semiconductors) are somehow special and expensive. You're paying for the design and brand, parts are more or less the same - you can easily get them in many shops.
@@k4syx You're responding to something I have never said... Pls. read again what I wrote.. A device called 'Coldmund' would almost by definition contain all fake components.. Fake Mundorfs, fake Nichikons, fake Wimas, any branded component will probably be fake.
These are either fakes or not. They are not exactly expensive even when buying in small amounts. But the worrying thing is you can get these on Ali. Anyway, it doesn't really matter because replacing these with locally sourced originals would be like 20USD here and it's 20-30 minute job. So, still outstanding value.
The seller SENGTERBELLE has no support. I asked for manual for the board and they don't provide. I can't find the instructions of the kit that this "JC-2" is made from. The power supply section is more involved that other JC-2 clones. Any one know what values should be set for Test Point A-B ?
@@errcl65 I was just going to write that I can check that in mine for you, but Its cool they have answered. I'va added this info to the video description!
@@errcl65Could you tell me where you measure the bias and which potentiometer you use to set the 440 millivolts? My device is arriving in Germany next week and I would like to measure it. Thanks for your help.
@dieterloebel2459 there are 2 test points on each channel labeled A and B.and GND. Also the +/-15 V test points four in total are in the middle of the board, also labeled.
I have now opened the preamp. Left side: B+ 0.712mv. A- 1.146mv. Right side: B+ 0.683mv. A- 1.116mv. 220v version. I cannot set A- lower than 0.560mv. B+ can be set to 0.440mv. What should I do now?
Glad to see these clone reviews.
Yay, you mentioned the Musical Paradise MP701.
I have the mk2.
Mk3 is on preorder....
Hope you get one in!
yeah, it looks like a winner! But I would not mind upgrading some of these cheap Chi-Fi preamps as well. this one really misses another set of preout for subwoofers or bi-amping.
and which sounds better mp or this one
@@00LongLong00
The MP offers so many tube and capacitor rolling options....
I'd start with the v-cap ODAM option and upgrade the stock tubes to get a neutral & holographic presentation.
Mundorf SGO Evo supreme caps give a more saturated tonal colour...
And that's just scratching the surface .
I keep a DENAFRIPS Hestia12th on hand for a baseline reference.
The MP is just more!
🎵🎶😉🎶🎵
Is this one id better tham MP71 mkii?
Thank you so much for doing these reviews :)
@@Rocker6969 Thanks!
if they manage to create a balanced version this could be a killer preamp!!
There are versions of the JC2 on AliExpress that DO have balanced inputs and outputs.
@@rontoolsie yeap I saw some of those but they lack a remote. Do you know a JC2 balanced with remote? If you do please let me know!! THANKS!!
Indeed!
Mine arrived quick. Ordered the premium version. Small amount of local tax. Sound out of box was thin. See after burn in. Very nice build quality. And my unit reads Goldmund!
How is it now?
@@sean_heisler Still think it is thin (front/back depth) sounding compared to tubes. Typical of S/S IMO. Serves its purpose in my casual listening S/S system.
@@errcl65 Thanks! I have both tube and SS preamps as well and I hear you. Once you have tubes in your system and you go back to solid state the thinner, very contrasty quality becomes quite noticeable. Did you see his review of the Accuphase clone? That sounds like it might be a little fuller sounding. You may be asking why I am looking at preamps when I already have two. I'm obsessed.
Yes. An excellent surprise. Interesting.
I am looking forward to your upcoming videos/thoughts on/aboutthose products you mentioned including the SMSL DO 200 Pro.
The burn in for them is complete, I just need (again) to take a few days off for listening session and video recording. Thank you!
@@k4syxyou will, of course, compare the DO 200 Pro (as a preamp DAC) with the other AliExpress preamps! This is in addition to reviewing the SMSL purely as a DAC. Thanks!
@@foblivio surely, no problem!
Try the Weilliang MBL 6010c clone... I got mine fron ebay at about $400 and then changed op amps for Sparkos and sounds great... Has both RCA and XLR inputs and outputs and a remote control as well..
It looks like there are 14 op amps inside the 6010. Did you replace all of them? Because at roughly $80 each, this would take the final product well into the $1000+ range
Hi, the Mundorff Capacitors actually seem to be real. And the popping sound is normal with "old-style" devices without delay-relais :)
All the Best, Sebastian
Hi Sebastian! Yes later it was confirmed by Mundorf that these are real - I know Christian asked them about that, we were corresponding then :)
Ive come across so many interesting clone amp boards on ebay, ive seen many folks assemble them and do videos on their quality. Id love to see someone who has the OG amp it was cloned from compare it DIRECTLY and get a realistic idea as to how close it might sound. Would love to see that.
@@AllboroLCD I think that's hard to see as diy folk rarely buy expensive branded amps, and the other way around: people buying very expensive audio stuff are not diyers so they won't usually even peek inside the cable they bought... :(
@@k4syx Totally understood. Theres a Jeff Rowland LM3886 amp & Pass Labs Aleph that most pique my curiosity. I mean if the circuits are 100% correct and enough power fed, The margin of difference will break down to the quality of components is my best guesstimate.
@@AllboroLCD exactly. Plus, pairing of the components - how well can you and will you match everything inside. All in all, these all are electronic circuits, no magic components there.
Very good build for the price...for instance the main R-core transformers each have two 15V 15VA windings, and are available on Ali for around $20 each...and there are two of them. Some other versions of the JC2 (including one that sells for $450) have much lower spec 7.5VA transformers which sell for only $9 each. Looking at all the JC2 versions, this appears to be the one to get.
It may be tempting to buy the most expensive version, thinking that it will be the best built and best sounding, but this probably does not apply here.
In the product description it erroneously says 'conrad-johnson' instead of "Mark Levinson'
Yes I got it based on the photos: they got my attention with such a nice and planned build. I just had to try it though I had no need for one more preamp ;) And yes they mention Conrad Johnson, looks like a paste from some other desc.
Thank you for another great product review. How does it compare sonically with the single input JC2 Max you reviewed a few weeks back?
Thanks. This one is better, though its _more_ expensive and lacks XLR outputs. This one is like 2x more expensive, the first one is excellent but two times cheaper. Both of them punch way above price level!
Is the FM 300A on its way ? That I'm looking forward to !!
I'm literally standing right now in line to get the parcel (delivery missed me on Friday)
@@k4syx rock and roll !!
Also, Xiangsheng 728A is interesting yes?
Looks good.
Thankyou for another wonderful video.
May i ask if i bought an amplifier from AliExpress and it was stated as 230v, should i expect 220v?
Kimd regards
220V and 230V are both basically same build, you'll be fine with either. My measured power voltage is more like 240 and thats still fine.
Set bias, finished rewiring with Mogami Neglex 2534. Used Stabliant 22A on 3 pin header on the relay gain board. All have positive audio improvements. I think all the pots need to be replaced with better ones which hold their setting. A lot of drift even in bias in idle. Same for psu rails. Sonically, very clean, very fast. Still early stages of critical listening.
@@errcl65 thanks for sharing, I'm happy it's sorted out. Yes, clean and fast are a very good words to describe it. It's very airy and transparent. I wonder about these Mundorfs, I will reach to them in Germany to ask if there are real ones with holograms. The ones I always bought locally (100prc.originals) never had anything like that regardless of the series (up to Evo silver in oil at least)
@@errcl65 oh and thanks for the tip on Mogami, I was wondering what should I use for some rewiring in other clones and you made me realize that I have some Mogami, Sommer and Canare unused in one of my "daddy's stuff, don't touch" drawers :)
Internally wire with same stuff you use for interconnects. And only shield ground the source end. Also from factory, input and output wires tie-wrapped together. Not a good thing...
@@errcl65 for ICs I usually used QED, I think these are to thick to be used here internally, but, again, that's also something from the same drawer. Ahhh I forgot, I also have some silver plated solid core OCC copper in Teflon coating! Will have to look there tomorrow =)
Aliexpress pots are $5 for 20. Real Bourne sealed are $7 each 100ppm/C. No wonder the rails and bais are going all over the place. 8 of them.. $56
They should be displaying INn instead of CHn because “channel” usually refers to left or right. Oh well, it’s ChiFi so understandable.
Denafrips Hestia display shows IN1,2,3.
Wish it was XLR1,SE2,XLR3 but now I'm nitpicking 😅
I enjoyed this review. i'm currently looking at the Sugden A21 or FM 300A and some of the Pass Labs clone. appreciate your input on these. thanks in advance.
I have a fm300a clone I really like it
I need to collect parcel with FM300A - TODAY! ;)
@@k4syx is it the the standard or the gold version?
@@MasterofPlay7 look at the photo I've just posted. Looks like standard (copy with the same looks). I think both versions are gold :)
@@k4syx yea I saw, I think the gold version has 2 transformers
Thanks for the look!
Regarding the smaller blue transformer.
It is NOT the primery reason of it existence to give any sound quality improvements.
This is a more normal and reqirued implementation today when you have remote and standby.
Legislations requrie that power consumption have to be lower at stand by.
So developers has implemented a smaller transformer with a relay (the light blue one) that cut out the two bigger transformers but consumes only small power that is needed to keep the IR alive to be able to switch it on by remote when it is in stand by.
In the past without the little dark blue transformer then the unit needed to keep the power on the much bigger main transformers in stand by.
When they draw more in stand by than a smaller transformer that gives us higher wattage drawn in stand by.
That is the primary reason for its existens, and it is nice to see that they comply to the power regulations in stand by.
Yes - and addtitionally its nicely separated from audio paths
Years ago I was part of a listening panel during R&D of a stand alone phono stage...which needed maybe a 10VA transformer. One day we listened to the identical stage hooked up to different transformers...all the way from a 30VA to a 250VA.
And every time a larger VA transformer was hooked up, the sound got better. Later on we tried a 500VA transformer and did not feel that the significant extra cost was worth it over the 250VA one.
But the gap between a 50VA and a 250VA was huge.
@@rontoolsie Yes, same here.
I got a very nice RIAA and upgraded to more than twice as big transformer (R-core).
But to be honest I did not hear any difference after the upgrade.
The sonic hearing memory is short and it were not any fast A and B comparison..
But I guess it were not worse anyway. 😉
Awesome! Is it availbale on eBay by any chance? I see some JC2 clones there but don't have your eye for internals...
@@SartajAnand No idea honestly, but look at the characteristic four white mundorf capacitors on the photos, I can check if that's the right device for you if you'll give some links here
Hi ,I would like to connect this Preamp to the 2 stereo power amps to have "vertical bi-amping" . One channel of the stereo amp would power treble and second channel for powering the base speaker of the same loud speaker. How to do that ?
So you basically need something like RCA splitter to have two RCA cables coming from preamp to both inputs on each power amp. You can get splitters like that for like 1USD on Ali or source them locally, they are quite popular.
@@k4syx Although electronically this would work, you should be careful if your power amps have low input impedances, since biamping them effectively reduces the load the preamp sees by 50%. For power amps with high input impedances than even cutting it in two still gives a high enough load. But amps with an input impedance of under 20kOhms may start to show roll-off of high frequencies and increased sensitivity to the length of the interconnects.
@@rontoolsie yes, exactly!
Do you happen to have instructions on what functions are hidden behind the volume key? F1 F2 etc. When you press the volume a menu appears
I got something like that:
SE1: Set default volume value for power on.
SE2: Set maximum volume"
SE3: Set the resistance change curve.
SE4: Set encoder rotation direction.
SE5: Set the backlight value.
SE6: Set volume mode to.
A few years ago I had a problem with the same ladder attenuator kit. It had a noise bump on one spot and also ground was shared on audio & control circuit...
Thanks, I'll look at shared ground. What was you solution to these problems?
@@k4syx If you don't have a problem don't worry, it was VERY noticeable! I guess they issued an update in the mean time... I had to cut some of gnd trace on attenuator pcb
I have noise on left channel. Developed 2 weeks after arriving. Will be scoping the outputs tomorrow.
@@errcl65 what kind of noise, can you share something more?
@k4syx power rails +/-15 messed. Cheap Potentiometer and right next to 67C heat sinks. Quiet now. Need to check bias, but no docs. I adjusted so both sides read the same 0.45V for now. They were not the same initially. One was .35V.
Where can I find the circuit diagram for this board? There are some potentiometers for bias setting. I want to confirm they are set correctly.
@@omadasmtp543 I think it may be possible to get one by contacting the store, these are schematics that are floating over the web but the thing is to know which one they have used.
Some of the stores even post diagrams as a part of description of the product so you can take a look before you buy anything
there is weird audible crack between 64 and 65 volume value and also hum noise in speakers which is more pronounced when going more up
and after 97 there is another jump in hum noise and its quite bad
@@martinhalmo5678 should be nothing like that. Have you looked inside for obvious transport damages (something got loose, moved inside?)
@@k4syx could be gain stages ? I run it into A1 power amp nothing seems to be moving inside there
your unit hasnt got any noise or hum at all ? even when you go over 65 volume level ?
@@martinhalmo5678 dead silent.. when I was doing the burn in, I've done it with low input level (lowered via DAC vol control) and high gain on preamp to have it more stressed.
Still, dead silent.
Maybe Soundstage and 3d will be there after cap change?
@@ferryvandijk3008 it's there, just not to extent of Accu clone. But it's possible!
@@k4syx thanks, i bought the power filter thank to your review.
Like how you discribe the products and compaire.
@@ferryvandijk3008 Thanks!
hello my friend.
I asked Mudorf whether the capacitors with holograms were real. Yes, they are real!!
Here is the text from Mundorf himself:
Good afternoon Mr. Schwarzbeck
The MCaps in the photos are real, no question.
We supply Chinese manufacturers directly from orders worth €5,000 or more.
Our distributor is responsible for this, and he also delivered the MCaps shown to the manufacturer.
Best regards,
Norbert Mundorf
Senior Global Sales & Marketing Officer
@@christian_schwarzbeck Hi Christian!
Thanks for the info, we've actually discussed this news in the comments as it was mentioned that you've actually reached to Mundorf and they confirmed it's real.
That's great news actually, excellent surprise!
Good morning...Ihave probleme. iwant to adjust the 0 mv. whitch test points can i use ihave a picture for the 15 volts and 0.440mv from the seller but the 0mv are missing (the middle volts)
AFAIK there are only two reference points, Errcl here had done that, look in comments below and ask for his experience. I've added "short" info to the description of the video when he shared what needs to be done.
This version has the xlr and vision meters and cheaper. so it's rcore or this vs Toroid, i wonder if it's even hearable less detectable on graph.
I dont know if PCB is the same though. If it is, then the sound should be close
Another great video mate, would be nice if you could review some good value tube clones. Placed an order for a balanced Dart 108 & currently looking out for a balanced tube pre to go as I’m running a 6m long interconnect. Looking forward thks.
I am thinking about Musical Paradise tube but it seems from the number of views on my Cayin reviews that we tube lovers are in minority here :)
MP701 has already gotten numerous reviews & well received. However it’s not a truly balanced circuitry & I’m not courageous enough to go down that rabbit hole of infinite variabilities thus some chi-fi clones would be more ideal for tight budget.
Something in the likes of CAT SL1 in my opinion, heard a genuine one decades back & it sounded really amazing but non XLR though or something you’d recommend.
The tube community is still strong, it’s the chi-fi community that needs more awareness.
Mine just developed noise on the left channel. Was fine a 2 weeks.
What kind of noise? Can you describe it?
@@k4syx cracking in the HF and some hiss. The right is dead silent. Unit was dead silent when I first go it 2 weeks ago. I will stick on the bench and scope the outputs today with grounded inputs.
@@errcl65 what exactly helped? changing the bias? (I've read the other two comments - thanks!)
@k4syx power rail adjustment. A noisy pot was messing -15v. I didn't test until i tweaked bias. I don't think it was misajusted bias cause random static.
May replace this 4 pots when I pooge in better signal cables.
I have 110v version.
Nice job, any thoughts on the C3850 clone? It seems a good topology , fully balanced in an out and good layout.
I've only seen photos, looks good, but I have no idea how does it sound
Question in general when ordering outside the country. Do you have to pay additional tax when the product arrives?
Customs, yes, sometimes you have to sometimes you dont, depends on the country and local law
@@k4syx do you know how much before purchasing?
The only thing the two channels electrically share is a common power cord. After that, it is effectively two completely separate mono preamps, housed inside the same chassis.
Most preamps have only a single power transformer with the filter caps shared by both channels, which are put on a single PCB. Years ago, I had a home demo of a 4 box Krell preamp with each channel having separate boxes with their own separate power supplies. It was pretty good too.
@@Reyfox1 you can try to asses maximum amount by knowing the value on the parcel and customs tariffs, on most cases the actual amount will be lower
Now everybody wants,needs balanced...
Ive been on a soapbox raving about true XLR kit for DECADES
Hi very interesting review indeed as usual
I think that the difference in details you perceive could be coming from the different attenuator type used in the two preamps
The blue pots are quite fine but nothing beats a network of good quality resistors
I do not know how many sections the Accuphase volume control has
But i would try a stepped attenuator in place of the rotary potentiometer
A 4 sections stepped attenuator however comes very expensive The very good ones cost more than the preamp under test
If you say that the 3D effect is better on the Accuphase for me this is very very telling
Only the very best equipment provide a great 3D soundstage Is the evidence of amazing linearity even at low signal levels
In conclusion my own guess is that the Accuphase is the better preamp circuit of the two
Do you know if the Accuphase is also availabe in kit form maybe ?
Thank you very much indeed Kindest regards gino
I haven't seen accu in diy kit :(
Accu clone is very 3d like, and this one seems like more transparent (but this doesnt mean that accu is not transparent - these are details that are apparent when switching between two of them. I am really curious about pairing these preamps - all three of them - with E-405 clone thats on its way to me)
@@k4syx hi thank you very much for your kind and valuable reply
I am pretty sure that a weak point in the Accuphase is its volume control
Often the fact that is branded Alps does not ensure that it is a genuine part
I did some test Even a cheap series attenuator was exceptional for detail
I can assure you that was a enlightning experience
The Accuphase circuit should be quite close to perfection
For me the ability to render a great 3D soundstage is everything
There are specific tracks to evaluate that but i am sure you know better than me
In the end i am pretty sure that both must be fantastic
Kind regards, gino
@k4syx What do you think about connecting this preamp to the FM 300A? Do you think it will sound good?
@@isavepro2011 yes, it will be a good match
Where exactly is the bias set and measured
@@dieterloebel2459 there are marked points on PCB and there are small pots for that. It's in the comments below (details)
Hi Tom (Tomász?) - many many thanks for reviewing this preamp! I think I am in serious danger of ordering it! 😂 Your recommendation of the Transaudio D5 Pro was exactly what I was looking for and I suspect that pairing it with this preamp will satisfy my input needs. I never listen to headphones these days anyway so the lack of a second output for the headphone amp doesn't hurt. I love that it should be very detailed, dynamic, airy with deep bass. I trust your judgement, especially after my experience with the D5 Pro. You may remember that I will be replacing a 38 year old exposure XI+XII Preamp combination which is *_still_* *very good* but perhaps has been eclipsed by other designs and newer components.
One question - do you have a suggestion for removing the silly gold-coloured "Coldmund" name plate? Warm air from a hairdryer perhaps? All black would suit my system aesthetics better. Greetings from rural Switzerland to Poland, All the best, Rob
Hi Rob!
I would try to use rubbing alcohol (isopropyl) and lift it from the sides as this is just a sticker :)
@@k4syx Hi! I have taken the plunge and bought one, it should arrive in about 2 weeks. I can't wait! My first new preamp in 38 years! Thanks for the tip about isopropyl alcohol! What's your burn-in process for a preamp? All the best, Rob in Switzerland
@@RobWhittlestone Hi! It usually takes about two weeks in a row. One week should be probably enough but since I don't always have the time to listen to the device it usually stretches a bit ;)
I leave everything on playing some test tracks with speakers facing each other and with one out of phase to make them quieter. I've made a video on speaker burn in, that's basically the same. I also have dummy 8ohm loads for amps, but these do not change with freq like real speakers do so I'm not using them now
@@k4syx Hi Greg - UPDATE: I received the device *but after only a few weeks' operation the device failed on one channel* during an evening with friends. It was feeding my Transaudio D5 Pro which went into self-protection mode. This happens if there is DC or very low frequency AC (
@@k4syxHi Tom, I bought it and was happy with it for about 3 weeks. Unfortunately, after 3 weeks it failed on the right hand channel with low signal output, loud clicks and pops and bangs, hissing and rustling sounds. I contacted the seller and they offered to pay for a repair or return it and they send me a new one. I have now shipped it to China and am awaiting further communication with the seller. They asked for a video of the defect which I was able to supply as a compressed MP4 file after many attempts trying to send links to the original MOV files. For the moment I remain neutral about the experience and have decided to trust the seller. I hope this was the right decision. Rightly they should cover the return costs. Let's see if they do.
All the best, Rob in Switzerland
You said this preamplifier is mono ? Ali Express says it is stereo, it does not say it is one channel only
Its dual mono, meaning that it is stereo but it has dual separate pathways for both channels
Any good clone dac you would recommend?
@@chrishmeet I haven't reviewed any, so I cannot recommend anything at the moment
@k4syx tanks bro, look forward to your review, new subscriber here
@@chrishmeet Thanks!
Got the preamp today. unfortunately not usable. There is a lot of hissing and humming from the speakers. After the FM 300, the next disappointment. The FM had similar problems. I've tried everything, including galvanic isolation. I am China clone cured.
@@dieterloebel2459 have you tried checking your power grid for DC component and /or using EMI filter for the power line? Cause it can't be just pure coincidence that you have two completely different devices in a row having exactly the same problem, not experienced by other folk?
I think that's something that I would put on my list of things to check :)
@@k4syxI used a DC filter. I also electrically isolated the connection between the preamplifier and power amplifier. unfortunately without success.
@@dieterloebel2459 Now thats even more weird. Any chance to get one of these to your friend in other part of the town or to your workplace to check it out in completely different power grid segment?
I really really strongly believe you have EMI interference in power line - Ive used to live near workshop with powered tools, and one the guys were powering angle grinders a lot of eqipement was going nuts. Same thing happens sometime if you have old or slightly damaged fridge, when its starting cooling it may feed emi back to the grid
@@k4syx I already had some devices here. Not a single one had such a problem. The clone is very sensitive there. I actually didn't want to buy a clone after the FM300. Now unfortunately it has hit me again. I already had 2 power amplifiers, 2 preamplifiers and 2 integrated amplifiers here in the apartment. I never had such problems as with the clones. It's a shame that the
somehow have a problem with the potential/ground.
@@dieterloebel2459 That's really really bad luck. One blind shot more: have you tried rotating power plug in the wall socket to get L and N the other way around? I know schuko will allow you to do that
I changed the output caps from the mundorf to Russian k75 pio and miflex kpcu 0.47uf bypass. Noticeable increase in tone and sound quality.
How can I contact you, please?
@@Christopher-l3l Just ask me here :)
@@k4syx We'd like to send you a product to test and try, are you interested?
Mund is German and means mouth, so Coldmund is Coldmouth.
I would think at some point, these knock offs will be fantastic
Yeah they are using ideas with patents expired and since it has been a few years they can use better parts and sometime improve original designs. Kinda like business version of diyaudio forums ;)
Apparently the Muldorf caps are real.
@@errcl65 I have to contact Mundorf on that. Haven't seen holograms on these earlier (and I do buy them locally) and there are other small differences. But maybe I missed something that happened during last year or so. Why do you think these are real? Have you seen them being sold somewhere in Europe?
@@k4syx The german channel that reviewed this unit confirmed with Mundorf, Germany. They say legit.
@@errcl65 that's very cool!
@@errcl65 Would that be Christian btw?
@@k4syx yes
By default I would imagine that a cheap Chinese device branded 'Coldmund' would have NO genuine branded components in it..
Goldmund is a expensive brand, but it doesnt mean that the components inside (resistors, capacitors, all semiconductors) are somehow special and expensive. You're paying for the design and brand, parts are more or less the same - you can easily get them in many shops.
@@k4syx You're responding to something I have never said... Pls. read again what I wrote.. A device called 'Coldmund' would almost by definition contain all fake components.. Fake Mundorfs, fake Nichikons, fake Wimas, any branded component will probably be fake.
how would one know if they were genuine Mundorf's and Nichicons . If its coming out of china its more likely my mum is a virgin
These are either fakes or not. They are not exactly expensive even when buying in small amounts. But the worrying thing is you can get these on Ali. Anyway, it doesn't really matter because replacing these with locally sourced originals would be like 20USD here and it's 20-30 minute job. So, still outstanding value.
The seller SENGTERBELLE has no support. I asked for manual for the board and they don't provide. I can't find the instructions of the kit that this "JC-2" is made from. The power supply section is more involved that other JC-2 clones.
Any one know what values should be set for Test Point A-B ?
Seller replied. Adjust bias so A-B test point should be 0.440V (440mV).
@@errcl65 I was just going to write that I can check that in mine for you, but Its cool they have answered. I'va added this info to the video description!
@@errcl65Could you tell me where you measure the bias and which potentiometer you use to set the 440 millivolts? My device is arriving in Germany next week and I would like to measure it. Thanks for your help.
@dieterloebel2459 there are 2 test points on each channel labeled A and B.and GND. Also the +/-15 V test points four in total are in the middle of the board, also labeled.
I have now opened the preamp. Left side: B+ 0.712mv. A- 1.146mv. Right side: B+ 0.683mv. A- 1.116mv. 220v version. I cannot set A- lower than 0.560mv. B+ can be set to 0.440mv. What should I do now?
I have plopping fron 63 to 64. is this normal?
ua-cam.com/video/EAx6-JTHDE0/v-deo.htmlsi=l690S6ROSZjgu2tJ
@@00LongLong00 it's not, Errcl here wrote about that, it was something that could be fixed easily but reach to seller first
@@k4syx OK, thanks, I'm in contact with the seller. Do you know how to fix this?
@@k4syx OK, thanks, I'm in contact with the seller. Do you know how to fix this?
@@00LongLong00 Errcl wrote something about a little weak power line for relays, you have to dig in the comments (don't remember the details)
@@k4syxi search and i cant not found 😢