I watched the Decware video. I didn't see anything that really contradicted your findings. Rather he was making an issue about channel matching distortion profiles and making a case for high distortion being OK and that for everyday use, high efficiency speakers are required. I think some people genuinely like the distortion it makes. You've pulled back the curtain to show that high harmonic distortion in SE tube amps is not necessarily a bad thing for some tastes. I'm sure there is some delusion aspect to the cult status of this amp in the mix. People see the golden ear guru reviews, buy the thing and are invested in the idea that it sounds great. I think you've done due diligence on this now.
The datasheet for this tube says just under 2W at 9% distortion triode strapped. And that's likely at the plate, factor in 85% for the OT and none of this is unexpected. Yeah I'm done here.
The coat hanger speaker wire test is proof that audiophiles do not know what they are talking about. Distortion? Can I hear 1 percent distortion? That’s the benchmark, right? I still remember the days of yore when the Yamaha’s, Marantz’s and Kenwood sand amps were rated to 1/100 %. And No one called themselves audiophiles back then. It was a great benchmark to use (1) if you were a cat and (2) to keep from buying some cheap $$@ stereo that was made by some private equity firm before we called them private equity firms and sold by some corporate monopoly chain store before there was a Best Buy. Long before EBay came along and all those Dynaco’s were going in garbage cans. Except for the Class D in my car (god, it’s a great time to be a kid - you can buy really cheap mean mobile sand), I run glass in my office and workshop. DIY glass and old glass. And they can sound awful ugly when they warm up. My Dynaco Mk III’s go through some downright ugly moments after firing them up in an unheated garage on a 30 degree morning- so does the ‘63 Studebaker that’s outside when I try to start it. It’s not automotive purity just like those dynacos aren’t audio purity- “it is what it is.” At some point it goes away. I have them things cranked when I’m working. I honestly can’t tell if I’m listening to The Stone Temple Pilots at 10 percent distortion or 1 %. Could be 50% at times. Would I want something else? No. It’s all subjective. What I can tell you is this: Dianna Krall butchers the singer standards no matter if it’s glass or an old portable 9V sand radio.
Decware has gotten criticism before and they will be just fine. People love the sound of this amp with hi-eff speakers despite power ratings and distortion levels. I was very curious to see your measurements. Thank you for making the time for us. Happy birthday!
I don't see this as criticism, it's a nice sounding 1W amp. If you watch the Decware video and listen, he says the same thing, use it at 1/2W. Not sure why people are freaking out over this finding.
To complete your comment..( half of the facts ).........most amplifiers and especially SS and allmost all amplifiers with NFB sound HORRIBLE below ONE watt.( Hard distortion )
Right, for the designed use case (use under 1W), this amp will sound great. I'm not sure why some of these Decware Fanboys are attacking me for pointing out the same information Decware themselves says. I probably am contradicting what some of the golden ears influencers are telling people? This little amp is not for everyone and every use.
You will and other people will always have this kind of comments and attitude ..important is to share passion, experience and share it with the many people who like to share with you .... :)@@SkunkieDesignsElectronics
I too bought into the hype originally and bought a Zen amp that looks exactly like the one you are testing. I became quickly disenchanted with it that amp when AB'ing it against other amps I own. I waited for 7 months for it as well. The wait and the cost are really too much for what you get. I can almost beat this amp with a lowly 65 dollar Fosi amp. I have an old Onkyo discrete transistor amp of 60 watts that just wipes the floor with the Decware. Just another one of those slippery slopes that happens when you have YT reviewers who praise this like its the best thing on the planet, yet when you get it and try it not so much. Dont really trust many of the YT reviewers anymore. I have used it with some efficient horns of 94 db spl and some Lii-song open baffles of 97 db spl so very easy to drive speakers yet this little amp really isn't what I like listening with very much. So it really hasn't been used much at all after waiting forever to get it. I will never buy another Decware unit though. Just too many better units out there that you can actually own in a matter of days not years. I applaud your tests and your honesty. I heard a lot of the same things you found with your test. The distortion, the lack of power. Also whats with not saying which way is hi or low on the transformer switch in the back thats just stupid. Plus my tubes did not come with a red tip either my amp is about 2 years old, so that could be a new thing.
Yeah… my SE84UFO is about 18 months old and it did not come with marked tubes either. I’m not sure when Decware started doing this. I’m happy with mine, though. Sorry it was a disappointment for you.
I got a Zbox years ago that he doesn't sell anymore. It was a buffer for improving the sound of CDs. It made an old blues recording sound smoother but killed the air and reverb ambiance for everything else. I was very close to sending it back. Years later unused i converted the circuit to a pre amp. But that doesn't sound good either bacause the voltage was set low to create soft cliping, the trick to make cds sound better. I will raise the input voltage and try again. I like the powder coated box with the tube inserted at the front. Its. Worh keeping just for that
All you did was state the facts and your seeing the same results as I have seen with a clone I built and tested but I used transformers not as good as decware so Iam seeing more of a drop-off on the low end. I couldn't agree more with your findings - I do like Triode sound but also like ultalinear with different type of music - That said I use my Decware clone near field with 98 speakers and it does sound really good to me and I have many tube amps of all kinds - push pull- 300B el34's 6550's KT120 etc and roll my amps every so often. In a larger room with less efficient speakers this will never cut it. If you enjoy the triode sound and have a small room with efficient speakers you'll probably love it. In the end it's a flea powered amp - nothing new under the sun here and can't see why people can't accept that.
I have seen rectifier tubes with poorly matching sections do something like you are seeing. Iam pretty sure you have checked that. I also appreciate your work to find the problem with the r300 output transformer
Given the video from Decware is showing similar results, there is nothing wrong with this amp, and all of this is what I would expect from a triode strapped EL84 running at this operating point.
Thanks for taking the extra time with that amp, I have Klipsch Forte IVs and wondered about that amp…definitely staying away from it…The Dennis Had amp would be a good one to test…I like ultra linear too…
I love the sound of my Dennis Had amp with Heresy IV. It’s rated at 7 watts. I bought it instead of the Decware to have a little more power. No issues with volume in my room.
Hi.You just proved that most people cant understand how to read tube amp measurement and how to use scope and generator.This amp works as you show and that's all!Thanks for extra explanation and your hard work:)
I think the majority of the hate is from people who didn't watch the whole video and just are knee jerk defending their purchase. The amp works exactly how it is designed to work and does a good job in that specific use, creating some even order harmonics at low power levels for sensitive speakers or low listening levels.
First off, happy birthday. I think you have thoroughly covered all the measurements of this amp. This amp is not for everyone. It requires very high efficiency speakers in order to take advantage of its abilities. People need to understand that they can't hook this up to speakers under 95 db efficiency and get much out of it. It could also work as a desk top amp in near field listening and work well. Here's the thing. You don't need more than 1 watt if you have the right speakers in the right setting. As long as you understand these parameters I'm sure it will do well. 95% of the people out there will be much happier with a solid state amp that will work well with most speakers on the market. However, there are a few of us who like the natural sound of a tube amp and are astute at selecting the right speakers and we aren't trying to achieve concert level volume in our listening area. This a niche item. Not a mass market item. Looking forward to your own amp coming to market!
If I understood correctly the Decware SE84UFO video, it is designed for a 1 watt average listening volume level and a 3 dB headroom (2 watts ) The use of high efficiency speakers is the key for good sound with low distortion with this amplifier. Skunkie Designs measurements are not far off when compared to the measurements presented here on an earlier video. Also, I have noticed Skunkie Design Electronics has three times the subscriber base compared to Decware. So, what is going on here? Unless someone is a Decware hard core fanatic, the numbers speak for themselves.
And Decware says this same thing in their video, although whatever software they are using is showing a little lower distortion % increase when the amp starts clipping (which seems odd to me, the clipping point normally starts the THD to spike). But you can clearly see the amp clipping at 2W on his measuring gear and he even points that out, as well as the odd order harmonics rising past 1W. This shouldn't be shocking to anyone.
I see people misunderstanding what this amp is, and trying to defend it as something it's not. It's a little amp designed to sound nice when used at 1/2W or so. And it does exactly that. Not sure why folks are getting all upset.
The old 6BQ5 GE data sheet lists triode strapped output as approx. 1.95 watts @ 9% THD into a 3.5k load. So 1.5 watts of clean power is all you would expect.
Oh dang! And there's me getting excited seeing the blank chassis pre punched out for the 3 b9a bases thinking that you are gonna announce your starting your Skunkie el84 build. 🙂 Never mind, patience is a virtue.
Hey, Stephe! “They say it’s your birthday. It’s my birthday too yeah!” Well, it was 2 weeks ago, but hope you had a great day. Thanks a ton as well for your straight forward answers and testing of these amps. Decware must’ve done they’re vid in response to yours. That’s pretty obvious. A friend of mine has 2 of them he runs as monoblocks into Klipsch Cornwalls, which are big and have a high sensitivity of around 98dB, which it seems you need to really let these amps sing. That said, I don’t understand the hype. I’m much more satisfied with the stuff I’ve DIY’d and built myself or bought “as is” and refurbished.
Thanks and Happy birthday …. Totally respect for Y’r review nice job….. Fineley one That we can trust… BIG THUMBS UP and Respect for Y Best regarsds from Denmark DK …. Please continue with What Y make Great…. and make a BIG Difference …. THANKS ;-)
I also watched the Decware video. If I remembered correctly Steve said this amp should work between a quarter of a watt to half a watt, the rest is headroom. This should perhaps be marketed as a one watt amp but I guess since it's a 1,5 watt amp, marketing it as a 2 watt amp is ok. Your measurements looks legit and do not really contradict Decwares. Good job!
Thank you for your review, I really like your channel and insight! I have the SE84UFO2.1 with all the upgrades. I too at first was wondering what all the fuss was about with this amp. I have it pair with Forte III's with a sensitivity 99dB @ 2.83V / 1m. I usually max out this set up at 70db max in a medium size room. I am not really into loud music. I like this amp at low level late night listening (CD/Streaming) with the right music it is magical! By the way my amp which is about a year old has the red tips on the tubes. I am looking forward to your amp!
Sounds like the perfect use for this amp. I listen more in the mid to upper 80db with mid to upper 80db speakers and it just wasn't made for my use. I need a solid couple of watts :)
Hi Troy, do you happen to notice any hum with your UFO and the 99dB speakers? I have the same amp with Lii Audio 98 dB speakers and have audible hum with the volume control all the way down and the inputs shorted.
@@ChrisHouseman Hello Chris, yes I have had issues with the humming and spitting (Both speakers). I replaced two 5U4 RECTIFIER tubes so far, one being the one that came with the amp. The first replacement solved the problem. However it just came back the humming and spitting "months later". I thought it might now be the INPUT TUBE since I replaced the rectifier tube. So, I wanted to order a 6922 ( Input tube) anyway (tube rolling) so I ordered the 6922 and installed it, it's still humming\spitting. So, just by coincidence I ordered a Electro-Harmonix 5U4GB EH Rectifier tube this morning. Some say it is bullet proof. Another person on a sight had a similar problem said this tube solved his problem. It's coming in tomorrow.
@@ChrisHouseman Hello Chris, the tube did not solve my problem. The more I think about it your problem my be different than mine. Mine is more sputtering than humming. With humming I think yours might be power/grounding or noise from other components have you tried isolating the amp direct power (removed from strip) and\or making sure no wires touching each other etc....?
My guess is quite a few folks are tube / power naive.. while my 300B gets to about 6 watts before clipping, 98% of my listening levels is at .5 to 1 watt.. Efficient speakers are simply a requirement with most tube gear... If an audiophile has sand amps AND speakers that waste power (inefficient speakers) but is happy with their setup, trying a first watt amp will not always work... kinda like putting a F1 engine in an 18 wheeler... if the goal is fantastic sounding music, i believe the audiophile should get the best efficient speakers they can 1st, before building the rest of the system. I have heard for 40+ years that speakers are the weakest link in any system. Kinda important to focus on that low hanging fruit first... The fact that this amp sounds amazing below 1.5 watts is fantastic. Anyone who thinks nothing can be done with that unfortunately is missing knowledge that cant be explained away.. My speakers are about 96db per watt and are full sized.... they fill the entire house with amazing sounding music quite easily, and at less then 1w of output...
Also the speakers need to be chosen for the environment they are used in. You also don't choose "full size" speakers for a small room and near field listening. They aren't designed for this and will never sound right. I guess my point, and I've said this in other videos, understand your requirements before you start and no component is "The component of the year" for every use.
Thank you for the thorough testing of that Decware. Have you heard of the Elekit TU-8200R Japanese tube amp kit? Anything good or bad on that sub $1K kit?
Few years ago I found somwhere on the net schematic of this amp and for my surprise the output L R triodes share the cathode resistor(can you verify this?) I think it cause like make little „wider stereo base” so maybe it is kind of trick this amp sound differently „better” for some peaples
At 10:28, I don’t understand what you are saying. The volume knob does allow you to attenuate the input signal to your liking, but that doesn’t imply amps don’t have an input sensitivity beyond which their performance degrades.
Turning down the volume knob, that lowers the input signal strength the first tube will see. Unless the source distorts at higher output levels: the amp's output clips at the same point with a .5VRMS signal as it will with a 2VRMS signal sent to the volume knob. The amps performance doesn't degrade with the higher signal, you just can't turn the knob as far before clipping happens. That is clearly shown in the video. It's a very common belief you can overdrive the input on an integrated amp and cause it to distort prematurely. like I said unless the source distorts at higher output levels, that's just not based on fact.
OK. So, I think we agree in some way. I.e., if the input signal level exceeds the input sensitivity of the amp, distortion and clipping will occur earlier in the range of the potentiometer. That in itself is tricky as you could have the potentiometer at 10 o’clock and already have high distortion or clipping if the input signal level is much greater than the amp’s input sensitivity. Sooooo…answering this question would be more insightful: How far am I from clipping when my target output SPL is reached? Obviously, that will depend on the sensitivity of the speakers, so everyone will get a different answer. Not trying to be difficult, just thinking out loud on ways to assess relevant performance.
Correct, clipping will occur earlier in the volume control range is all a hotter signal will do. But it's not going to change at what output or SPL this happens.
Given how thorough you are with your testing (which is a one reason why I watch this channel), I am curious if you would do some testing on another flea powered amplifier that has gained some recognition in the DIY realm and that is the Darling amplifier. It uses a nice looking shouldered 1626 tube and puts out only 3/4 watts. However, many say it is a great sounding amplifier on efficient speakers...and it doesn't cost $1200 either.
looks like datasheet performance for a triode mode 6bq5. Sheet calls for 9% THD and 1.95 watts, but thats plate power. Output transformers are ballpark of 85% efficient so that 1.95 plate watts becomes about 1.6 watts at the speaker. Nothing about your measurements surprises me.
I'm really baffled at folks who think a flea power amp like this is gonna make big music using inefficient speakers, like it has some magic pixie dust inside it?
@@SkunkieDesignsElectronics thats why I don't really run my little amp. It makes 4 watts, but my speakers aren't efficient enough to make good use of it. Sounds fine at lower levels but it runs out quick. 100+ db efficient speaks and I'd be jamming though.
So what are we testing here? The system has some really nice transformers and a signal-path featuring 2 resistors and 1 capacitor. Essentially you are testing tubes. Are those the original tubes and have they been matched? Clearly not, according to your results. (Decware's tubes come with red tips, so you have aftermarket ones on the amp) Why not get a hold of a matched set of tubes from Decware so that you can rule out dodgy tubes?
Did you watch the Decware video? It shows the amp clipping before 2W too and the same odd order harmonics. And there is more to distortion/performance than just the tubes, where they are biased, how the plate loads are configured, how good the output transformers are all weigh into it. The owner said these are the tubes he got with the amp and I'm not seeing any variation from one channel to the other. Anyway, clearly you are looking for a reason to believe this is more than it is. It's a nicely built 1W amp.
@@SkunkieDesignsElectronics Yes. I don't have a Decware amp, but I did once, an early iteration of this one called the SE84ZS. It was a helluva nice amp for the money. The question is, can we buy a nicely built, but better amp under 2.5W for under US$1500? I doubt it very much. But yes, a 2.3W amp will clip somewhere before 2W. Playing a 2.3W amp at much more than 1W is nuts anyway, as with high sensitivity speakers, 1W is pretty loud! I'm just offering some advice on further investigation, which is to get some decent tubes form Decware, and go from there. Those on that amp are not from Decware, so the biasing will be off. Decware tubes are specially marked for warranty purposes, so if they don't have the marking, they are questionable. Additionally, our ears tend to enjoy some distortion, which is a big reason why single ended tube amps, and these Decware amps are much loved. Looking forward to the next episode with the correct tubes!
The owner said he bought these tubes from Decware about 3 years ago. I have no reason to believe he is lying to me. Two commenters above say they bought this amp and the tubes don't have this "red tip" thing either, are they lying too? And no, a 2.3W amp shouldn't clip before 2W, yet they clearly show in Decware's own video it is. And one last time for the people in the back, used under 1W this amp sounds nice. 2-3% of even order harmonics are not a problem. Decware themselves say to use it at 1/2W or so. I'm not sure why you are trying to defend this amp as something even Decware says it's not...
I’m not defending the amp so much as criticising the poor scientific method in the testing. The trickle down effect from Big Pharma’s bad science perhaps has diluted our sense of reason. God knows we put up with crap science every day, but when things are not done right at the basic level, it irks me. I’m not one bit worried for Decware though. With a backlog of orders exceeding 4 years, they will easily survive the bad scientific methods of their detractors. The ears are the ultimate test after all, not the conclusions drawn from untested tubes and testing equipment.
This is the quintessential YMMV scenario. Everyone is stating the same facts, but what they mean varies by the person. Some people will happily restrict themselves to 98+ dB sensitivity speakers, so they can experience the SET magic, and that gives them like a dozen speakers in the known universe to listen too, and half are made by Klipsch and cost a ton of money.. Others want to be able to go at least down to 88 or so dBs in choosing a speaker. Is your system all about the amp or the speaker? Decware has always been more about the amp -- proven by all the effort they put into finding speakers their amps can drive. I think this is great though, I watched the Decware video and never before heard Steve say, flat out, you're gonna clip at 1.5 watts on my "2.3 watt" speaker. And this is not a criticism of Steve. People will tell him they are having a great time with 90 dB speakers and a UFO amp. What's he supposed to say? Your speaker choice is wrong? If you never listen above 85 dB at 1 meter -- and this does apply to a lot of people I think -- then again we're back to YMMV. 85 dB at one meter is not how Skunkie listens to music, as far as I can tell. Wanna turn it up and dance in a big living room, the UFO doesn't deliver punch and power if you have an 88 dB speaker. Which however is a very common sensitivity.
100% The other thing to remember is headroom, transients will spike and if you are listening on the verge of clipping, those transients are going to be clipped. Which is why even the Decware video is saying this is intended to be used at 1/2W or so to allow for that.
So they are trying to take advantage of the simple minded, using used car salesmen technics , the reviewers out there saying this is gold should be embarrassed, i have really limited my selection of reviewers that i listen to. Great job i am sure you will get some hate mail from them.
@@SkunkieDesignsElectronics There's a bit of sunk cost fallacy going on, it's understandable that they'll be upset, don't worry yourself too much, you're giving a very objective analysis.
That must be it, it's already started. I'm really not saying anything different than Decware says in their video, use it at 1/2W or maybe a little more and it will work nicely.
I said that multiple times. It's when it starts making odd order after around 1.5W, it stops sounding nice. Decware says this same thing in their video, use it at 1/2-3/4W to leave some headroom. This isn't rocket science :)
Stephe, do you have any background in electronics or audio engineering. Your poinions sound like a hobbyist, so I take them opinions with a grain of salt.
Wow competitive much😂That amp is meant to run high sensitivity speakers around 100dbl (mine are a bit more) and if so will never clip as they will 99% of the time run mini watts but anyway those amps soft clip when pushed but even if your speakers are 85dbl then you will get near 90dbl outta them with the Decware which is loud in the average room and you know that the hormonic distortions are what make valve amps special right? The best measuring amps can be cold and lifeless to the ear. (I don't own one but ive heard them) love your channel Skunkster.
I'm guessing you didn't watch the video, I have said multiple times if you are using 1/2-3/4W it works fine, The Decware video says this too, go watch his video. And even order harmonics are what make tube amps sound good, odd order/clipping never sounds good.
Distortion can be driven down to have a good measuring amp though the use of negative feedback, but that comes at the expense, for some listeners, of “cold”, “lifeless”, “sterile” sound, something we either don’t or don’t know how to measure or quantify.
Followers of my channel will know I preach some THD is good, but it needs to be even order, not odd order. I even made a "color" preamp that is designed to introduce an adjustable amount of even order THD into the signal. clearly I would hope people would know by now and even from watching this video I said multiple times, using this amp in the zone where it's making even 2-3% even order THD it will sound good. But I'm never going to buy into some nonsense about an amp driven to "soft clipping" and is pumping out 3% odd order harmonics sounds good there.
What are you missing? Fawning fanboys. Well over 20 years ago, I built one of his kits and ran it on an old set of CV towers. It was a cheap and fun setup. I was on their forums quite a bit and everyone was objective. Then the Audio-phallics zeroed in. Next thing they’re telling everyone to buy gold plated power cables. Sitting around in socks drinking wine while critiquing how Michael Frank’s version of Popsical Toes” sounds on their $4000 whizzer cones. Because of course they think they can hear what my cat hears. They placebo effect that it must sound better when you throw more money at it - check out the coat hanger speaker wire test sometime.
Yeah, that became clear when all those fanboys descended on my channel lol. I love how they did a video in response to mine, and on a scope show the exact same results I showed.
@@SkunkieDesignsElectronics I really have a peeve/vendtta against audio phallics. Over the years I have seen people find some joy in something- smart people- seek advice - only to get shot down because some jackoff is going to tell them to look up the specs.. yet on the Decware forums they are some owned fanboy b!tch that are blindly obedient to Steve Deckert. Don’t get me wrong- I know Steve. Steve Deckert is a great guy. If it wasn’t for him, I wouldn’t be building Dynaco’s for scratch, lol. Seriously, I’ve talked to him. I’ve also talked to his wife and daughter. I’ve ordered stuff from him. He has given me advice. He’s a small businessman who has built a family business and he is truly passionate about it. Like Steve, I run a business, too. Where Steve is brilliant is that he knows how to gauge his core customers. He did that by creating the Decware forums- and he monitored it. This way (1) he comes off as approachable- which he genuinely is and(2) he can gauge his target demographic customer. Because there sure as a hell of a lot more money selling gold plated boutique power cables than selling kit amps that were powder coated in machinery grey. I cannot blame Steve for that. He has mastered how to give everything his customers want.
Good to be thorough and give everyone benefit of doubt, so they can't dump all over you. Love watching your analysis as well! 👍
I appreciate that!
I watched the Decware video. I didn't see anything that really contradicted your findings. Rather he was making an issue about channel matching distortion profiles and making a case for high distortion being OK and that for everyday use, high efficiency speakers are required. I think some people genuinely like the distortion it makes. You've pulled back the curtain to show that high harmonic distortion in SE tube amps is not necessarily a bad thing for some tastes. I'm sure there is some delusion aspect to the cult status of this amp in the mix. People see the golden ear guru reviews, buy the thing and are invested in the idea that it sounds great. I think you've done due diligence on this now.
The datasheet for this tube says just under 2W at 9% distortion triode strapped. And that's likely at the plate, factor in 85% for the OT and none of this is unexpected. Yeah I'm done here.
@@SkunkieDesignsElectronics Yes, sobering numbers!
The coat hanger speaker wire test is proof that audiophiles do not know what they are talking about.
Distortion? Can I hear 1 percent distortion? That’s the benchmark, right? I still remember the days of yore when the Yamaha’s, Marantz’s and Kenwood sand amps were rated to 1/100 %. And No one called themselves audiophiles back then. It was a great benchmark to use (1) if you were a cat and (2) to keep from buying some cheap $$@ stereo that was made by some private equity firm before we called them private equity firms and sold by some corporate monopoly chain store before there was a Best Buy. Long before EBay came along and all those Dynaco’s were going in garbage cans.
Except for the Class D in my car (god, it’s a great time to be a kid - you can buy really cheap mean mobile sand), I run glass in my office and workshop. DIY glass and old glass. And they can sound awful ugly when they warm up. My Dynaco Mk III’s go through some downright ugly moments after firing them up in an unheated garage on a 30 degree morning- so does the ‘63 Studebaker that’s outside when I try to start it. It’s not automotive purity just like those dynacos aren’t audio purity- “it is what it is.” At some point it goes away. I have them things cranked when I’m working. I honestly can’t tell if I’m listening to The Stone Temple Pilots at 10 percent distortion or 1 %. Could be 50% at times. Would I want something else? No. It’s all subjective.
What I can tell you is this: Dianna Krall butchers the singer standards no matter if it’s glass or an old portable 9V sand radio.
Decware has gotten criticism before and they will be just fine. People love the sound of this amp with hi-eff speakers despite power ratings and distortion levels. I was very curious to see your measurements. Thank you for making the time for us. Happy birthday!
I don't see this as criticism, it's a nice sounding 1W amp. If you watch the Decware video and listen, he says the same thing, use it at 1/2W. Not sure why people are freaking out over this finding.
Agreed.@@SkunkieDesignsElectronics
Fine comments ........right so as intended ....@@SkunkieDesignsElectronics
I just canceled my order.
Happy Birthday Stephe! You missed nothing that I could see.
Happy birthday 🎈 thank you for all the wonderful fun content!!
Thanks for telling it the way it is. The measurements are clear. Not much you can do with 1.5 watts.
Happy birthday 🎂
To complete your comment..( half of the facts ).........most amplifiers and especially SS and allmost all amplifiers with NFB sound HORRIBLE below ONE watt.( Hard distortion )
Right, for the designed use case (use under 1W), this amp will sound great. I'm not sure why some of these Decware Fanboys are attacking me for pointing out the same information Decware themselves says. I probably am contradicting what some of the golden ears influencers are telling people? This little amp is not for everyone and every use.
You will and other people will always have this kind of comments and attitude ..important is to share passion, experience and share it with the many people who like to share with you .... :)@@SkunkieDesignsElectronics
I too bought into the hype originally and bought a Zen amp that looks exactly like the one you are testing. I became quickly disenchanted with it that amp when AB'ing it against other amps I own. I waited for 7 months for it as well. The wait and the cost are really too much for what you get. I can almost beat this amp with a lowly 65 dollar Fosi amp. I have an old Onkyo discrete transistor amp of 60 watts that just wipes the floor with the Decware. Just another one of those slippery slopes that happens when you have YT reviewers who praise this like its the best thing on the planet, yet when you get it and try it not so much. Dont really trust many of the YT reviewers anymore. I have used it with some efficient horns of 94 db spl and some Lii-song open baffles of 97 db spl so very easy to drive speakers yet this little amp really isn't what I like listening with very much. So it really hasn't been used much at all after waiting forever to get it. I will never buy another Decware unit though. Just too many better units out there that you can actually own in a matter of days not years. I applaud your tests and your honesty. I heard a lot of the same things you found with your test. The distortion, the lack of power. Also whats with not saying which way is hi or low on the transformer switch in the back thats just stupid. Plus my tubes did not come with a red tip either my amp is about 2 years old, so that could be a new thing.
Yeah… my SE84UFO is about 18 months old and it did not come with marked tubes either. I’m not sure when Decware started doing this. I’m happy with mine, though. Sorry it was a disappointment for you.
This one was bought about 3 years ago, I had no idea "red tip tubes" was a thing...
I got a Zbox years ago that he doesn't sell anymore. It was a buffer for improving the sound of CDs. It made an old blues recording sound smoother but killed the air and reverb ambiance for everything else. I was very close to sending it back. Years later unused i converted the circuit to a pre amp. But that doesn't sound good either bacause the voltage was set low to create soft cliping, the trick to make cds sound better. I will raise the input voltage and try again. I like the powder coated box with the tube inserted at the front. Its. Worh keeping just for that
Changing the plate voltage/plate load/bias point of the tube could help in your use case.
Happy birthday, Steph!
I will follow your channel while it exists.
My respect
Happy Birthday. And keep on your track.
All you did was state the facts and your seeing the same results as I have seen with a clone I built and tested but I used transformers not as good as decware so Iam seeing more of a drop-off on the low end. I couldn't agree more with your findings - I do like Triode sound but also like ultalinear with different type of music - That said I use my Decware clone near field with 98 speakers and it does sound really good to me and I have many tube amps of all kinds - push pull- 300B el34's 6550's KT120 etc and roll my amps every so often. In a larger room with less efficient speakers this will never cut it. If you enjoy the triode sound and have a small room with efficient speakers you'll probably love it. In the end it's a flea powered amp - nothing new under the sun here and can't see why people can't accept that.
Yeah, and Decware says the same thing basically.
excellent truths,,,, why we dont touch this brand for decades
I have seen rectifier tubes with poorly matching sections do something like you are seeing. Iam pretty sure you have checked that. I also appreciate your work to find the problem with the r300 output transformer
Given the video from Decware is showing similar results, there is nothing wrong with this amp, and all of this is what I would expect from a triode strapped EL84 running at this operating point.
Thanks for taking the extra time with that amp, I have Klipsch Forte IVs and wondered about that amp…definitely staying away from it…The Dennis Had amp would be a good one to test…I like ultra linear too…
I love the sound of my Dennis Had amp with Heresy IV. It’s rated at 7 watts. I bought it instead of the Decware to have a little more power. No issues with volume in my room.
Happy Birthday !!! Best wishes !
Happy Birthday!! Mine was last Friday.
Happy birthday!!
Hi.You just proved that most people cant understand how to read tube amp measurement and how to use scope and generator.This amp works as you show and that's all!Thanks for extra explanation and your hard work:)
I think the majority of the hate is from people who didn't watch the whole video and just are knee jerk defending their purchase. The amp works exactly how it is designed to work and does a good job in that specific use, creating some even order harmonics at low power levels for sensitive speakers or low listening levels.
@@SkunkieDesignsElectronics That's why I like your channel :-)
Great video and great testing. Happy Birthday.
Thank you! Cheers!
First off, happy birthday. I think you have thoroughly covered all the measurements of this amp. This amp is not for everyone. It requires very high efficiency speakers in order to take advantage of its abilities. People need to understand that they can't hook this up to speakers under 95 db efficiency and get much out of it. It could also work as a desk top amp in near field listening and work well. Here's the thing. You don't need more than 1 watt if you have the right speakers in the right setting. As long as you understand these parameters I'm sure it will do well. 95% of the people out there will be much happier with a solid state amp that will work well with most speakers on the market. However, there are a few of us who like the natural sound of a tube amp and are astute at selecting the right speakers and we aren't trying to achieve concert level volume in our listening area. This a niche item. Not a mass market item. Looking forward to your own amp coming to market!
Happy Birthday from Northern California!
Great video as always---hope you had a happy birthday!
I did!
If I understood correctly the Decware SE84UFO video, it is designed for a 1 watt average listening volume level and a 3 dB headroom (2 watts ) The use of high efficiency speakers is the key for good sound with low distortion with this amplifier. Skunkie Designs measurements are not far off when compared to the measurements presented here on an earlier video. Also, I have noticed Skunkie Design Electronics has three times the subscriber base compared to Decware. So, what is going on here? Unless someone is a Decware hard core fanatic, the numbers speak for themselves.
And Decware says this same thing in their video, although whatever software they are using is showing a little lower distortion % increase when the amp starts clipping (which seems odd to me, the clipping point normally starts the THD to spike). But you can clearly see the amp clipping at 2W on his measuring gear and he even points that out, as well as the odd order harmonics rising past 1W. This shouldn't be shocking to anyone.
Decware has ~3,000 amps on order - doubt they care much about UA-cam subs. So, what is going on here?
I see people misunderstanding what this amp is, and trying to defend it as something it's not. It's a little amp designed to sound nice when used at 1/2W or so. And it does exactly that. Not sure why folks are getting all upset.
@@SkunkieDesignsElectronics I’ve owned it since 2016. I know what it is and isn’t.
There you go. It is what it is. We can all go to bed. 🤣 Happy Birthday!
Yes, I seriously couldn't sleep thinking about what I had to have missed. Like you said, it is what it is.
The old 6BQ5 GE data sheet lists triode strapped output as approx. 1.95 watts @ 9% THD into a 3.5k load. So 1.5 watts of clean power is all you would expect.
Right, this isn't shocking news to most of us :)
Oh dang! And there's me getting excited seeing the blank chassis pre punched out for the 3 b9a bases thinking that you are gonna announce your starting your Skunkie el84 build. 🙂 Never mind, patience is a virtue.
Thank you for an insightful video
Glad it was helpful!
Hey, Stephe! “They say it’s your birthday. It’s my birthday too yeah!” Well, it was 2 weeks ago, but hope you had a great day. Thanks a ton as well for your straight forward answers and testing of these amps. Decware must’ve done they’re vid in response to yours. That’s pretty obvious. A friend of mine has 2 of them he runs as monoblocks into Klipsch Cornwalls, which are big and have a high sensitivity of around 98dB, which it seems you need to really let these amps sing.
That said, I don’t understand the hype. I’m much more satisfied with the stuff I’ve DIY’d and built myself or bought “as is” and refurbished.
Happy Birthday!
Happy Birthday! Hope you have a wonderful day.
Thank you so much!
Thanks awfully for all this information. You've saved me the time that I would have invested building a clone, as the schematic is on Decware's URL.
For some uses and some people's taste, it's a great choice. But it's not for everyone, nor is it for every use case.
Thanks and Happy birthday …. Totally respect for Y’r review nice job….. Fineley one That we can trust… BIG THUMBS UP and Respect for Y
Best regarsds from Denmark DK …. Please continue with What Y make Great…. and make a BIG Difference …. THANKS ;-)
So many great comments here pointing out common ground. Great viewers here.
Happy Birthday! 🎂
Thank you!!
I also watched the Decware video. If I remembered correctly Steve said this amp should work between a quarter of a watt to half a watt, the rest is headroom. This should perhaps be marketed as a one watt amp but I guess since it's a 1,5 watt amp, marketing it as a 2 watt amp is ok. Your measurements looks legit and do not really contradict Decwares. Good job!
Thanks and yeah, I don't understand all these folks who are upset.
Thank you for your review, I really like your channel and insight! I have the SE84UFO2.1 with all the upgrades. I too at first was wondering what all the fuss was about with this amp. I have it pair with Forte III's with a sensitivity 99dB @ 2.83V / 1m. I usually max out this set up at 70db max in a medium size room. I am not really into loud music. I like this amp at low level late night listening (CD/Streaming) with the right music it is magical! By the way my amp which is about a year old has the red tips on the tubes. I am looking forward to your amp!
Sounds like the perfect use for this amp. I listen more in the mid to upper 80db with mid to upper 80db speakers and it just wasn't made for my use. I need a solid couple of watts :)
Hi Troy, do you happen to notice any hum with your UFO and the 99dB speakers? I have the same amp with Lii Audio 98 dB speakers and have audible hum with the volume control all the way down and the inputs shorted.
@@ChrisHouseman Hello Chris, yes I have had issues with the humming and spitting (Both speakers). I replaced two 5U4 RECTIFIER tubes so far, one being the one that came with the amp. The first replacement solved the problem. However it just came back the humming and spitting "months later". I thought it might now be the INPUT TUBE since I replaced the rectifier tube. So, I wanted to order a 6922 ( Input tube) anyway (tube rolling) so I ordered the 6922 and installed it, it's still humming\spitting. So, just by coincidence I ordered a Electro-Harmonix 5U4GB EH Rectifier tube this morning. Some say it is bullet proof. Another person on a sight had a similar problem said this tube solved his problem. It's coming in tomorrow.
@@troy5220 Please let me know if the new rectifier helps. I have tried many, but not that specific tube.
@@ChrisHouseman Hello Chris, the tube did not solve my problem. The more I think about it your problem my be different than mine. Mine is more sputtering than humming. With humming I think yours might be power/grounding or noise from other components have you tried isolating the amp direct power (removed from strip) and\or making sure no wires touching each other etc....?
Wishing you a Happy Birthday !! You sure made my day with these 30 mins. 😀 The truth and nothing but the truth with numbers and facts. 😊
Yes! Thank you!
My guess is quite a few folks are tube / power naive.. while my 300B gets to about 6 watts before clipping, 98% of my listening levels is at .5 to 1 watt.. Efficient speakers are simply a requirement with most tube gear... If an audiophile has sand amps AND speakers that waste power (inefficient speakers) but is happy with their setup, trying a first watt amp will not always work... kinda like putting a F1 engine in an 18 wheeler... if the goal is fantastic sounding music, i believe the audiophile should get the best efficient speakers they can 1st, before building the rest of the system. I have heard for 40+ years that speakers are the weakest link in any system. Kinda important to focus on that low hanging fruit first... The fact that this amp sounds amazing below 1.5 watts is fantastic. Anyone who thinks nothing can be done with that unfortunately is missing knowledge that cant be explained away.. My speakers are about 96db per watt and are full sized.... they fill the entire house with amazing sounding music quite easily, and at less then 1w of output...
Also the speakers need to be chosen for the environment they are used in. You also don't choose "full size" speakers for a small room and near field listening. They aren't designed for this and will never sound right. I guess my point, and I've said this in other videos, understand your requirements before you start and no component is "The component of the year" for every use.
Thank you for the thorough testing of that Decware.
Have you heard of the Elekit TU-8200R Japanese tube amp kit?
Anything good or bad on that sub $1K kit?
No idea on that one, sorry.
Few years ago I found somwhere on the net schematic of this amp and for my surprise the output L R triodes share the cathode resistor(can you verify this?)
I think it cause like make little „wider stereo base” so maybe it is kind of trick this amp sound differently „better” for some peaples
They do.
At 10:28, I don’t understand what you are saying. The volume knob does allow you to attenuate the input signal to your liking, but that doesn’t imply amps don’t have an input sensitivity beyond which their performance degrades.
Turning down the volume knob, that lowers the input signal strength the first tube will see. Unless the source distorts at higher output levels: the amp's output clips at the same point with a .5VRMS signal as it will with a 2VRMS signal sent to the volume knob. The amps performance doesn't degrade with the higher signal, you just can't turn the knob as far before clipping happens. That is clearly shown in the video.
It's a very common belief you can overdrive the input on an integrated amp and cause it to distort prematurely. like I said unless the source distorts at higher output levels, that's just not based on fact.
OK. So, I think we agree in some way. I.e., if the input signal level exceeds the input sensitivity of the amp, distortion and clipping will occur earlier in the range of the potentiometer. That in itself is tricky as you could have the potentiometer at 10 o’clock and already have high distortion or clipping if the input signal level is much greater than the amp’s input sensitivity.
Sooooo…answering this question would be more insightful: How far am I from clipping when my target output SPL is reached? Obviously, that will depend on the sensitivity of the speakers, so everyone will get a different answer.
Not trying to be difficult, just thinking out loud on ways to assess relevant performance.
Correct, clipping will occur earlier in the volume control range is all a hotter signal will do. But it's not going to change at what output or SPL this happens.
How does it sound compared to your modded A10?
At the 1/2W to 3/4W level, it sounds better. If you are needing over 1W, the modded A10/12 is going to sound better IMHO.
Given how thorough you are with your testing (which is a one reason why I watch this channel), I am curious if you would do some testing on another flea powered amplifier that has gained some recognition in the DIY realm and that is the Darling amplifier. It uses a nice looking shouldered 1626 tube and puts out only 3/4 watts. However, many say it is a great sounding amplifier on efficient speakers...and it doesn't cost $1200 either.
In the future, sure.
looks like datasheet performance for a triode mode 6bq5. Sheet calls for 9% THD and 1.95 watts, but thats plate power. Output transformers are ballpark of 85% efficient so that 1.95 plate watts becomes about 1.6 watts at the speaker. Nothing about your measurements surprises me.
I'm really baffled at folks who think a flea power amp like this is gonna make big music using inefficient speakers, like it has some magic pixie dust inside it?
@@SkunkieDesignsElectronics thats why I don't really run my little amp. It makes 4 watts, but my speakers aren't efficient enough to make good use of it. Sounds fine at lower levels but it runs out quick. 100+ db efficient speaks and I'd be jamming though.
So what are we testing here? The system has some really nice transformers and a signal-path featuring 2 resistors and 1 capacitor. Essentially you are testing tubes. Are those the original tubes and have they been matched? Clearly not, according to your results. (Decware's tubes come with red tips, so you have aftermarket ones on the amp) Why not get a hold of a matched set of tubes from Decware so that you can rule out dodgy tubes?
Did you watch the Decware video? It shows the amp clipping before 2W too and the same odd order harmonics. And there is more to distortion/performance than just the tubes, where they are biased, how the plate loads are configured, how good the output transformers are all weigh into it. The owner said these are the tubes he got with the amp and I'm not seeing any variation from one channel to the other.
Anyway, clearly you are looking for a reason to believe this is more than it is. It's a nicely built 1W amp.
@@SkunkieDesignsElectronics Yes. I don't have a Decware amp, but I did once, an early iteration of this one called the SE84ZS. It was a helluva nice amp for the money. The question is, can we buy a nicely built, but better amp under 2.5W for under US$1500? I doubt it very much. But yes, a 2.3W amp will clip somewhere before 2W. Playing a 2.3W amp at much more than 1W is nuts anyway, as with high sensitivity speakers, 1W is pretty loud! I'm just offering some advice on further investigation, which is to get some decent tubes form Decware, and go from there. Those on that amp are not from Decware, so the biasing will be off. Decware tubes are specially marked for warranty purposes, so if they don't have the marking, they are questionable. Additionally, our ears tend to enjoy some distortion, which is a big reason why single ended tube amps, and these Decware amps are much loved. Looking forward to the next episode with the correct tubes!
The owner said he bought these tubes from Decware about 3 years ago. I have no reason to believe he is lying to me. Two commenters above say they bought this amp and the tubes don't have this "red tip" thing either, are they lying too?
And no, a 2.3W amp shouldn't clip before 2W, yet they clearly show in Decware's own video it is. And one last time for the people in the back, used under 1W this amp sounds nice. 2-3% of even order harmonics are not a problem. Decware themselves say to use it at 1/2W or so. I'm not sure why you are trying to defend this amp as something even Decware says it's not...
I’m not defending the amp so much as criticising the poor scientific method in the testing. The trickle down effect from Big Pharma’s bad science perhaps has diluted our sense of reason. God knows we put up with crap science every day, but when things are not done right at the basic level, it irks me. I’m not one bit worried for Decware though. With a backlog of orders exceeding 4 years, they will easily survive the bad scientific methods of their detractors. The ears are the ultimate test after all, not the conclusions drawn from untested tubes and testing equipment.
This is the quintessential YMMV scenario. Everyone is stating the same facts, but what they mean varies by the person. Some people will happily restrict themselves to 98+ dB sensitivity speakers, so they can experience the SET magic, and that gives them like a dozen speakers in the known universe to listen too, and half are made by Klipsch and cost a ton of money.. Others want to be able to go at least down to 88 or so dBs in choosing a speaker. Is your system all about the amp or the speaker? Decware has always been more about the amp -- proven by all the effort they put into finding speakers their amps can drive.
I think this is great though, I watched the Decware video and never before heard Steve say, flat out, you're gonna clip at 1.5 watts on my "2.3 watt" speaker. And this is not a criticism of Steve. People will tell him they are having a great time with 90 dB speakers and a UFO amp. What's he supposed to say? Your speaker choice is wrong? If you never listen above 85 dB at 1 meter -- and this does apply to a lot of people I think -- then again we're back to YMMV. 85 dB at one meter is not how Skunkie listens to music, as far as I can tell. Wanna turn it up and dance in a big living room, the UFO doesn't deliver punch and power if you have an 88 dB speaker. Which however is a very common sensitivity.
100%
The other thing to remember is headroom, transients will spike and if you are listening on the verge of clipping, those transients are going to be clipped. Which is why even the Decware video is saying this is intended to be used at 1/2W or so to allow for that.
So they are trying to take advantage of the simple minded, using used car salesmen technics , the reviewers out there saying this is gold should be embarrassed, i have really limited my selection of reviewers that i listen to. Great job i am sure you will get some hate mail from them.
I'm sure I will get hate mail/comments from owners too.
@@SkunkieDesignsElectronics There's a bit of sunk cost fallacy going on, it's understandable that they'll be upset, don't worry yourself too much, you're giving a very objective analysis.
That must be it, it's already started. I'm really not saying anything different than Decware says in their video, use it at 1/2W or maybe a little more and it will work nicely.
HB!
No hard clipping ! Si
That's even-harmonic distortion. That's why people like it.
I said that multiple times. It's when it starts making odd order after around 1.5W, it stops sounding nice. Decware says this same thing in their video, use it at 1/2-3/4W to leave some headroom. This isn't rocket science :)
@@SkunkieDesignsElectronics Yeah, sorry, I wrote the comment before I finished the video. 😁🤔
Steve Deckert needs to drop his claimed output to 1.5 W/ch.
Give him another 20 years. He’s come down from advertising FIVE in the 1990’s.
Stephe, do you have any background in electronics or audio engineering. Your poinions sound like a hobbyist, so I take them opinions with a grain of salt.
You might want to go watch Steve's video on the amp, his test results show exactly the same thing mine do.
HB! 🙂
Wow competitive much😂That amp is meant to run high sensitivity speakers around 100dbl (mine are a bit more) and if so will never clip as they will 99% of the time run mini watts but anyway those amps soft clip when pushed but even if your speakers are 85dbl then you will get near 90dbl outta them with the Decware which is loud in the average room and you know that the hormonic distortions are what make valve amps special right? The best measuring amps can be cold and lifeless to the ear. (I don't own one but ive heard them) love your channel Skunkster.
I'm guessing you didn't watch the video, I have said multiple times if you are using 1/2-3/4W it works fine, The Decware video says this too, go watch his video. And even order harmonics are what make tube amps sound good, odd order/clipping never sounds good.
Distortion can be driven down to have a good measuring amp though the use of negative feedback, but that comes at the expense, for some listeners, of “cold”, “lifeless”, “sterile” sound, something we either don’t or don’t know how to measure or quantify.
Followers of my channel will know I preach some THD is good, but it needs to be even order, not odd order. I even made a "color" preamp that is designed to introduce an adjustable amount of even order THD into the signal. clearly I would hope people would know by now and even from watching this video I said multiple times, using this amp in the zone where it's making even 2-3% even order THD it will sound good. But I'm never going to buy into some nonsense about an amp driven to "soft clipping" and is pumping out 3% odd order harmonics sounds good there.
@@SkunkieDesignsElectronicsHopefully, someday, I’ll get a chance to hear one of your amps, maybe if your 12AX7/E34 SE amp plans pan out.
Decware takes too long to get anyway. Plenty of other companies out there.
What are you missing? Fawning fanboys.
Well over 20 years ago, I built one of his kits and ran it on an old set of CV towers. It was a cheap and fun setup. I was on their forums quite a bit and everyone was objective. Then the Audio-phallics zeroed in. Next thing they’re telling everyone to buy gold plated power cables. Sitting around in socks drinking wine while critiquing how Michael Frank’s version of Popsical Toes” sounds on their $4000 whizzer cones. Because of course they think they can hear what my cat hears. They placebo effect that it must sound better when you throw more money at it - check out the coat hanger speaker wire test sometime.
Yeah, that became clear when all those fanboys descended on my channel lol. I love how they did a video in response to mine, and on a scope show the exact same results I showed.
@@SkunkieDesignsElectronics I really have a peeve/vendtta against audio phallics. Over the years I have seen people find some joy in something- smart people- seek advice - only to get shot down because some jackoff is going to tell them to look up the specs.. yet on the Decware forums they are some owned fanboy b!tch that are blindly obedient to Steve Deckert.
Don’t get me wrong- I know Steve. Steve Deckert is a great guy. If it wasn’t for him, I wouldn’t be building Dynaco’s for scratch, lol. Seriously, I’ve talked to him. I’ve also talked to his wife and daughter. I’ve ordered stuff from him. He has given me advice. He’s a small businessman who has built a family business and he is truly passionate about it.
Like Steve, I run a business, too. Where Steve is brilliant is that he knows how to gauge his core customers. He did that by creating the Decware forums- and he monitored it. This way (1) he comes off as approachable- which he genuinely is and(2) he can gauge his target demographic customer.
Because there sure as a hell of a lot more money selling gold plated boutique power cables than selling kit amps that were powder coated in machinery grey. I cannot blame Steve for that. He has mastered how to give everything his customers want.
Decware is expensive