PASS ACA amp revisited: Bad China Clone (of course it is...) 

The truth hurts. I’m tired of people who scream in judgment without having a clue what they’re talking about. We need more people like you who have the courage to be honest and the skills to back it up.

You’re more than an extremely competent amp builder and designer, you definitely know your stuff, and the majority of your 8,000 subscribers know that as well. These people with all the complaints have likely never seen any of your older videos, and many are probably basing their conclusions on sims and have likely never built a damn thing…lol. Like the guy who said he’d “built” over 200 amps…🤦‍♂️ These types of people are the reason I rarely go on forums anymore. This is supposed to be a fun hobby. Thanks, Stephe. Keep up the absolutely fantastic work.

Skunkie I love your no bullshit, no snake oil, no promotion, hifi reviews 😊❤

Keep doing what you do! You explain things at such an in-depth level that is both educational and enjoyable. From Jay's Iyagi to Mr. Audiophiliac they're full of opinions based on feelings and will endorse anything that comes their way. They wouldn't know a piece of test equipment from a toaster oven. We need more content like YOURS!

Try not to let the trolls get to you. I think most of these people need validation on some gear they purchased based on a RU-vid “ influencer “ told them sounded great. I appreciate your honest reviews. It’s pretty telling when some RU-vidrs are always hawking the best amplifier and then the next day have another the very best amplifier. Obviously just shilling for advertising dollars and views. Don’t let these folks get to you. Keep putting out these great honest reviews.

So upset to here you have been getting so much crap , I am a 54 year old Australian Who Was lucky enough to have a Dad That was an electrical engineer . I was given an understanding of electrical equipment that most people who are into electrical equipment would never have , I always enjoy your videos & find your reviews & tutetorals to be exceptionally good & entertaining . Please keep up the good work

Hi , please continue what you are doing with your honest reviews. Till now I have the bad experience with two products which were praised by the “professional audio experts “ as being very good but sounded as garbage.

I appreciate your candid reviews. As well, the same can be said about Danny at Gr Research. Just keep doing exactly what you're doing and the audio world will be a better place for all of us.

A lot of people suffer from 'the sunk cost fallacy'. This is when people invest time and/or money into something that is ultimately bad but they are unwilling to accept this, to accept they may be deceived. I am like you, if I buy a product and it sounds rubbish, I will say so. I am glad you are one of the few YT reviews who tells it as it is.

One of the problems you will have is, people just do not know what actually sounds good ,bad or indifferent. I worked in pro audio all my life where a single channel strip on a quality studio costs more than any amplifier you can buy. So they buy stuff, it colours the sound if they are lucky red blue white or whatever and they sometimes have to like it because…… someone told them it does. Then there is consistency which is not existent in china unless you pay for it. So keep on rocking babe.

Nice to hear you stand up for your opinions. No need to apologize. 🙂 When your channel grows, the amount of haters will increase increase too. Just the reality for RU-vidrs unfortunately. Keep up the good work! 👏🙏

Just the channel I've been looking for. Always curious on these cheap imports and modding them to perform! Good stuff!

This exact thing happens in every single niche. Gaming CPUs, playing cards, turn tables, car engine building, and on and on. There's a lot of know-it-alls who never put in any actual real world work, but will swear they know what the best products you should be using.

Stephe, don’t let the trolls get you down. If you listen to other reviewers, they never review a bad product. everything they review is great. Most on this channel appreciate your honesty and letting us know when a product is bad. Keep up the good work.

Great job! Good to hear this. I’ve been doing hifi audio my entire life. Some stuff I hear reaaallly makes me wonder. Keep up the awesome vids

Great video…your honesty is why I always come back to you! No BS is the truth…well done and pls keep your extraordinary work! Be safe. Cheers..

Knew you would get beef when I saw your vid. Fair play to you for having the courage to speak out. My diy amps sound great to my ears. I wish i had your talent and equipment so I could measure them too. I can only test by ear. Not all people in the forums are the same and one or two of the forums are great. One in particular that I am a member of is suberb, never encountered an issue yet. They have helped me through all of my builds and members have even offered to come over and help etc.

Love your content, have really learnt a lot from your channel and value your opinion, thank you!

Keep doing EXACTLY what you've been doing! What do people expect for a couple of hundred dollars in this hobby. People are looking for premium products for nothing. Folks, it doesn't exist.

Looking forward to it. Always enjoy your video's, I'll keep watching, thanks

Thanks for making the video, I have been looking for more info on this exact topic

Hi, as mentioned in many reviews, the ACA Pass as a stereo amp can only be considered an interesting trial. I suggest you give it a try as a mono block connected to one side and one 90dB speaker ( I don’t think you will want to spend the extra $350 for a second one) As such it delivers very nice 5w ( wild assumption) and becomes worthy of bearing the name Pass. And carry on with the good work, I’m a solid state person who watches all your presentations 😊 who knows, I might switch to tube power amps one day

You needed one of those directional Hi-fi fuse's for $10000.😂 You are awesome, just takes time for people to get used to honesty when they are sold on lies.

I listen to people who review amplifiers and it is easy to tell those who play music and those play music and listen to music. If you don't play a real instrument then you have no idea what one should sound like. I built my first 4 channel amplifier in 1963 as a teenager, no amplifier has a true reproduction of all audio frequencies, all amplifiers will favor a given frequency and then slightly cut the others at the input stage; that because you have a capacitor and resistor in the input circuit for isolation. Keep up the good work, solid state is easy. Look at transistors as nothing more than 1/2 of a 12XA7 and IC's as switching device with some of them with mini circuits in a small package.

I'm sorry to hear that Skunkie Designs suffered comments from people who are not understanding and not kind. I really enjoy your videos. I don't doubt for a second that the Chinese clone doesn't sound good. The first serious preamp and amp I ever bought were from Nelson Pass's short-lived Forte brand. The sound was wonderful. I ran them for 33 years and they never broke down. In fact, the preamp had no power switch and was designed to always be powered on. ...and still it never failed. Then I started building amps and preamps from kits so I sold the Forte gear. I've built the WHAMMY! Headphone amp, a First Watt F6 clone, and a First Watt F4 clone. They all sound great. I wasn't too interested in the Amp Camp Amp because it was designed to get beginners interested in building electronics. It can be built in a day. It's a pretty simple circuit. The diyaudio version uses a 24 Volt Meanwell power supply. Nelson measures everything he designs, and while that little amp can't compete with other more expensive designs, it should produce Nelson's measured results. I was disappointed to hear the Chinese clone sounds awful especially since it appears to have a linear power supply. I am betting that if you build the diyaudio version, it will match Nelson's measurements and sound decent. At the risk of sounding like a diyaudio fanboy the cost of a complete kit is high because so few are made. There are part-time workers who source all the components from major suppliers (Digikey, Mouser, etc.). They have to be paid. The chassis are made by a separate company in Italy. There is a Build Guide on-line which costs something to put together. One good thing is that you can just buy the printed circuit boards for $25 and then source all the components yourself including a Chinese-made chassis. I can tell you from experience that it is difficult to bring the diyaudio amps in for much less than the kits are priced. The diyaudiostore is a non-profit business venture. Nelson contributes the designs. The hope is to involve more people in building electronics. As you know it's not that difficult. I hope my comments help. Keep up the great work you are doing.

One of the reasons I watch all of your videos is because you dig deep and measure everything so that we can understand the relative performance of equipment. You then attempt to improve the performance in areas where you found a need and room for improvement. Then you retest and do more listening and almost invariably you are successful. BRAVO!!! Your honesty and integrity is what we like and what the nay sayers don't have. Stick by your work. Almost all of your followers feel the same way. NEVER LET A FEW SOUR PUSS"S RUIN YOUR DAY!

Thank you for your honesty and standing your ground. Integrity

Its funny, I was butthurt about the ACA because I'm a fan of Nelson Pass amps. I've owned a few and found them impressive. I have always wanted to build an amp from scratch but ordering parts from an XL BOM is intimidating. Having a kit in a box sounded pretty good to me!! But then again I watched your review of the A12 as mine was in the air. When I listened to it, you were dead right.. Junk! I was going to sell the A12 but now I think I will do your mod and see how it goes; XL BOM be damned. If I enjoy it, and am successful I may still do the ACA. I love my current tube and SS amps so for me its all about the build and learning. This controversy clarified that for me, so something good came of it. It just sucks that it was at your expense but it'll pass and we can all get back to enjoying your work. Stay strong.

Thank you for your videos. Im not a DIYer, and for music- I'm a headphone guy.. I really like the triode sound of tubes, ultralnear is too close in sound to solid state to my ears, so I see no point in having an ultralinear tube amp. Ive been wanting to get a 300B tube amp primarily for HP use and possibly speaker usage later on..but theyre so darn expensive from Felix Audio, Woo and Cayin! I was hoping for a less expensive alternative through Willsenton or Boyourange. Too many problems for my liking! The search for a sub $1500 before tubes, on a single chassis, good sounding, RELIABLE 300B headphone amp with a well tuned output transformer continues. Thank you for saving me from a horrible expensive mistake!

You are the best! I like your videos and so super you share for free all schematic in your website THANKS FOR ALL!

Having had experience with Chinese low-cost IEM's, headphones, tube phonos, tube amps and having seen many conflicting reviews of these, I think what we have here is a lack of product consistency. Quality control of parts and build is obviously one of the points where costs are saved.

People are happy to criticize this and that. No matter what. Thanks God we have all these platforms now. Highly appreciate the technical content of this channel.

Your channel is awesome! I have a couple of the ACA amps that I built a couple years back. In my Opinion, they do sound good. In stereo “mode” they measure around one percent distortion at 4-5 watts into an eight ohm load using the analog discovery two. I was using an industrial DC to DC converter for power with a 40,000 microfarad capacitor bank. Never mind the dopes talking crap to you, the audio world is loaded with them!!!!

Love your content, refreshing

I'm a bleeding edge state of the art solid state guy who also has a number of tube and solid state STAX rigs. The majority of commercially available solid state Amps/Preamps even many of the supposed ultra high end ones are abysmal.

I appreciate your candor.

Sorry you have gotten those bad comments. I agree with person below, you are a great builder & 'explainer'. Keep up the good work!

Bin in electronics manufacturing for a while now, and you are spot on. I am a audio junkie to. 35 years now. I would not even pay attention to the hate. You are completely correct. Chines parts in the kits are 90% of the time fake. It is amusing when you assemble one on a industrial machine, and the parts explode and the pins fall thru the board.🤣 I have seen whole reals of amazing fakes. Packaging and all. Was glad when I found your channel. You have covered a lot of kits and topics I have bin interested in. Again don't sweat it about people with pore hearing and bad audio pallet. I always say "Money cant buy you good taste."✊ also, the "aca" is a mediocre amp compared to a grate amp. It was meant to get your feet wet, not end game.

If the climax with original ACA boards going to turn out to be aha! wow! moment?! Then.... things gets more complicated. However this is thriller. Awaiting... :)

i appreciate your vids...as i buy a lot of "china" stuff as its sometimes cheaper....anyways i was wondering if you could or would do an R2R dac build...you can get the boards and such pretty cheap...i been wanting to build one for a long time just dont have the know how yet,would love to see you do one.

First, i am a tube lover. That said built an official aca- nelson pass amp and was surprised to hear Stephies results. I only have one tube preamp to drive it, and while is could not sound anything like my 300B was not unhappy with it. If I had a better preamp, id probably have given it more thorough listening test... its unfair of me to compare it as we all know garbage in=garbage out. That said Id be more than willing to loan it to Stepie for a testing session... From understanding, sand based amps by nelson are designed around the mosfets, and that only some can make the cut. So the design can not be easily adapted to variations of the intended parts.. if i wasn't so happy with my current setup, id try the color pre-amp with the real aca amp camp for certain...

I think you’re great! Don’t worry too much about the gadflies who purport to know everything. Wherever you go, they will always be there, dedicated to pooping in the pool. Keep going! Love the channel. Peace, Steve

Thanks for the info on the midpoint voltage. To be honest, I am hoping that adjusting this will get my Hood 1969 amp at least listenable but if not, I can on-sell if to crowd who think JLH and Pass amps are good.

Thanks for your honesty 🎷

Right on about the cult status non-sense. Love that you never buckle!

My first time seeing you talk. You are awesome. people who don't understand electronics and home audio, however they heard there buddy's boze and it sounded best...lol. not to say there is anything wrong with bloz...😂😮

Thanks for the update on the E6.. I guess you’ve exhausted all the tweaks you could to improve this tube gainstage/buffer lol.. That FX Audio is said to improve a lot with better Opamps and caps, and a better smps or lps.. I just got the newer FX 03 from a buddy who needed money, I hope it works as a gainstage/buffer for my old multibit dac with a non standard

With all the respect you deserve People have different hearing and different opinions Nelson Pass it's good but does not match with other audio manufacturers

A decent Class A amp should not have that much distortion. Not to mention all the other problems with Class A, such as the amount of heat they generate even without any load on the amp. I understand the obsession with Class A amps and I previously a great sounding Class A headphone amp (Creek OBH-11SE) that I listened to in bed, but one time I forgot to turn it off before going to sleep, and it ended up destroying my sheets by the time I woke up the next morning, because it got too hot (not even playing music, but still turned on). I think the best solution is a kit for one of newer Class D amps, and using a separate tube preamp to get the kind of "sweet" sound that most people are looking for in tubes or Class A. There are some new Class D kits out there with lots of power and incredibly low distortion, and I think it would be good for Skunkie Designs to look into those instead of any Class A solid state amps. A lot of fairly decent audio companies like NAD and Peachtree are moving to Class D for their full range amps.

There are plenty of know it all fanatics out there. I value your opinions and your work. I have listened to many different components that others said were great but sound like shit to me.

Hello , im looking to purchase an amplifier from Japan. Can o use it with USA current with a converter or something like that? Thanks for any help.

Hope you have better luck with the knob heads at DIY Audio. If you give them a call there only answer to go to the forum. No help at all. Then there's the issue that you buy the boards your interested in and they come with no instructions or schematics so you have too look everywhere to find them only to find out all these things were designed ages ago and that most of the parts like MOSFETs and JFETs are all discontinued. Then totally useless in recommending an alternative, so back to a forum that was last written 10 years ago. Would have been nice to know it's not really a working kit before I bought anything. Now 2 years later I finally track down all the bits, build my amp (with the alternatives) and like you said it sounds like crap. Please bring on the KT88 mono blocks. Can't wait.

Non illegitimus, non carborundum. Don't let the trolls wear you down. I think that many "audiophiles" buy gear based upon brand name and physical appearance, rather than listening to the fruits of their purchases. They also need to recognize that all reviews are opinions (yes, I know that measurement are significant, but it still has to sound good), and different folks have different opinions. Also, the genre of the music you prefer has a profound effect on your impression of the sound of a component. Life is not simple.

Let's see if original boards make a difference.. big Passlabs fan of their products and their customer care.

Well said, Stephe. There is a lot of politics at DIY Audio. And some irrationality. Mr Pass has an interesting business model. He puts out these simple DIY designs and thus has a solid following and this allows him to charge large amounts for his 'genuine' gear. Pretty smart really. And he gets Guru status along the way. I have made some of their gear - overall, I would give them an 'OK' status. None of my gear from there is used much. It is OK but far from special. (Now I will await the flack too)

Kudos for having the balls to be honest...👍🏻👍🏻👍🏻

haters are useless.. harassment. thank u for all hard work... And u kow better.

Please don't let any of these trools get your goat ... forums everywhere are just full of them- you'll never get away from them - just ignore them- for DYI crowd your the TOPS!!!

Don't you worry about those "trolls" Steph. They are everywhere!

Yeah I'm sorry that you're having problems with the solid-state scene. Well it's true you can get a lot of good deals on stuff on eBay obviously from China. But the difference between having something that just works and something that is decent, will require some modifications. What you can do is study the datasheet of the main component of the amplifier and see where they cut corners to make it affordable. Then right the wrongs and that will give you a quality product. Anyway that's worked quite well for me. I will be posting on my channel specifics on how to do this for a $18 250w class D amplifier.

Ok Brought the E6 Tibe PreAmp U are correct 💯 the Fosi Preamp with upgraded OPAmps and Tubes sounds beautiful for the most part if someone has never heard good sound many things will sound good , Even when they absolutely don't ( to a trained ear)

In a moment of weakness I bought that same China ACA clone. Its well made and sounds pretty good but a bit thin and hazy sounding. For fun I swapped out the 15 volt power transformer for an 18 volt transformer of the same 100 watts because a bigger one would not fit and I doubled the size of the capacitor filter bank. I think that made it sound better. Then I sold it on eBay for about what I paid for it. After that I built a First Watt F5 which sounds a lot better than the ACA. I began to wonder what an ACA would sound like with a really beefy power supply so I built one with a 400 watt power transformer. Sounds good but it still sounds like an ACA. Then I built a 6V6 SE tube amp and there's no turning back. The Pass amps sound kinda dead in comparison. No criticism there of Nelson Pass. Just the reality of what solid state amps sound like compared to tubes. I think the issue with these Chinese clones is that they skimp on the power supply because that's what costs all the money in a decent amp. Looking forward to more of your videos and don't let the knuckleheads get you down.

Good for you. There will always be a group of people that get butt hurt when someone doesn't rave about a product they purchased. I value your opinion and facts more so than some jackwad RU-vidr that likes to hype whatever the next new product is, that probably didn't pay for the product and has his/her own agenda as to why they give glowing reviews to mediocre or garbage products. Either way, just keep doing your thing, I really enjoy your content.

You just became more interesting then you already are

i agree with you about the cables are a rip of, most of them look shiny,so it have to be good, i never use cables more expensive then 150euro

That kit is a good deal! You get a nice enclosure, toroidal transformer and jacks, for just the price of the transformer! Look on the bright side.

I like your voice, but I think I love your dog.

The Steve Audiophile Guy likes PASS gear and is actually friends with Nelson Pass, but he cannot build any of the kits himself due to age related losses in eye-sight and dexterity and he relied on a younger guy to build his kit, so you are definitely in a different ball park then him being able to build your own stuff and having experience with lots of different models. Have you bought any prebuilt gear from china, I have the Hood 1969, Naim NAP250 and NAC52. I am enjoying them but have yet to hook up my Marantz PM6007 that I bought last year to compare against the China Naim components which cost me equally as much for comparison.

Please take a look at the new Bob Carver RAM285.

Like the way you think! 👍😁👍

First time seeing one of your videos so; Where is the test equipment?

These people are fanboys - and just like e.g. Apple, Thermomix or Tesla fanboys (or any other kind), they're uncritical about the thing they follow even if it has obvious disadvantages or is downright crap. And if you say anything they don't like, they'll jump on you, totally butthurt. These buffoons make the audio enthusiasts' community unwelcoming. I love your honesty, your rants and your work - keep that up

Wouldn't let them get you down. Keep giving your opinion about what you hear, what you see. The A10 only sounded ehh to me and that was through 100 db Klipsch Heritage speakers, still had no bass, The A50 was better through the 100 db speakers but still wasn't all that. BTW with the 100 db speakers Im not even using 1 watt. When I finally got the Willsenton R300 it just walked all over the A50 across the board including bass. Solid State, I just don't do cheap on solid state, have never had luck with cheap solid state. One question, do you really consider pre-assembled cards and plugging them together DIY? To me DIY would be actually getting the circuit boards ans actually soldering the resisters, capacitors etc to the board. I assemble my own computers but I really don't consider it diy, building it from scratch. Just my opinion, you don't have to answer if you think it would bring you the trolls.

If you make 6SQ7 6550, this ACA can't beat

Love your videos and opinions. Cult-like audio dopes crack me up. Ignore...

Give ‘em hell Skunkie! Sorry to see you so upset over these “experts”. Don’t forget, you’re involved in small town politics. This crap from these trolls oughta be like water off a duck’s back. Love ya.

“Cult”, is a strong word… I’ve built a couple of the DIY ACA amps - the ones from the DIYStore. I’ve also built the ChiFi boards. Put four of them running in parallel with dual power supplies, specifically built for 4ohm loads. I was also fortunate enough to get one if the VFet amps from the DiYStore lottery. Have to say, I have been very pleased with all of them. I’ve also built a Hiraga 30 Class A amp, a SE EL84 amp, recapped and repaired a bunch of other amps. By no means an expert by any stretch, but no noob either. 40 years of listening to various pieces of hiring kit, meaning I’m not a noob with that either. Currently have about 10 different amps, some preamps, some integrated amps, some tube and some solid state. Also have about 10 different pairs of speakers ranging from single drive full range to 3 way horns and electrostatics. All that to say, have a bunch of stuff I can play with here. The ACA amps work really well with the right speakers. As we all know, synergy is everything. I look forward to hearing your findings after you replace the boards in the amp. Would also like to know what you think if the amp with a full, range driver. Cult, is a strong word…

I found an affordable Conrad & Johnson SV12 clone in the net. I hope it's worth.

No matter what people think they should be respectful for the expertise that you offer FOR FREE! People who insult people who are helping them are really on my bad side. Lets have a productive discussion here. :)

Ignore the trolls, they are probably fanboys of that particular brand. Looking around the net for diy amp kits is a right eye opener, personally l would go for something like Bob Latino or Dynaco kit builds.

I love channels like this, anyone have any more suggestions? I know xraytony’s channel & live it too.

People forget, Steve was a salesman for the industry, even more so now he's an influencer. He even chuckles to himself in some 'reviews', he knows a large majority are going to take his word for it without really auditioning different gear. Whole HI-FI world is full of influencers, hardly any of them are actually reviewers. I recently got banned from commenting on one channel, literally because I politely said I was skeptical of a product being pushed by the person in question as he is friends with the designer of the product.🤦😂 I didn't trash talk the thing in question, was merely making a point that clearly there was a conflict of interest, especially given the praise heaped upon the said product that was far and beyond gear that is widely known to be excellent. Nature of the game these days, people are easily fleeced and these peddler's of 'audiophile' pretentiousness are doing pretty well for themselves.

I meant to say Steve Guttenberg can't hear well anymore

Holy Grail? No, they got sidetracked at Castle Anthrax (Monty Python).

Are you Glasslinger's daughter?

Well, I do like your channel and no b.s. approach to stuff, but you shouldn’t expect a ChiFi amp to sound like a Amp Camp Amp. ACA’s are for acquiring soldering skill, satisfaction of making something that works and just having fun. I occasionally watch ASR, he hates Klipsch speakers, and he needs to consider listening to what he’s measuring. You listen and measure and that’s good. I listen and judge by listening; I wish I had something to measure with but…. I have 3 amps designed by Nelson Pass and love them. I have a Macintosh amp that’s my favorite, the Audiophiliac doesn’t like it. Everybody likes and dislikes something for all kinds of reasons. Are your 300B amps for sale? Do yo make tube amps without a volume pot that you would sell? I’m interested.

Thumbs up for the truth about this stuff:)

I've got 3 china amps....best sounding amps....china amps!!! 🙂

Hey there Don’t listen to the naysayers and their nonsense. You keep being you and we’ll all be better for it. Heck enjoy their misery even

I agree with you, I don't understand why the heck Nelson Pass tweeks his solid state designs to add euphonic distorsión and produce a couple watts of power, when that can be done easily even low power tubes. You hit the point, there is a cult status for several personalities and brands in the high fi world. There is nothing that angers and annoys people more than making them aware of the truth, it's painful when you have to admit you have become and act as an idiot. Many hifi brands market their products not for the performance, electronic design or parts quality but instead on how much a customer will be willing to pay for the name and the status, that is the truth of many US made brands. I know what I am talking about, I own and have own several of them. Many of this products are good, but not all that great if you consider what you pay, certainly not a great bang for the buck.

Meow, im a cat

Anybody that would have the experience to know is you.

Да все нормально, не парься. Это народ. Когда вышел на публику будь готов ко всему и не обращай внимания на баранов.

i have the fm300a clone and am a micro electronics engineer so i know what i'm talking about, but the 300a ain't bad for the money ,most normal brands ask also too much for their simple amplifiers which use standard circuits ,you can copy from a book

🫂👍👍👍👍🙋

all china DACs & amps sound the same!!

Hello hun miss seeing you here .excellent info 👍

Good on u say it the way it is I'm sick of people saying stuff is good then buy it and it's shit so good on you

Do the people who ''belittled ''you even own the gear in question? Listened to ?

Its hard to ignore the morons, but do your best , remember if you like it then its good for you