2nd DIY amps from diyaudio. All seemed easier than the first time. PCB design is beautiful, instruction is clear enough. Very happy to have both preamp and pw amp (amp camp amp) done by myself. Thank you very much for your site, will plan the next shopping here, maybe a tube amp.
Perfect parts received, exactly as my CAD file. I love the quality, especially the scripted text engraving.
My M2X is still in progress. So I can`t tell you how the different input boards affect the sound.
PCBs are very good quality (as always!). Delivery was very fast. But customs take their time
(it was around christmas time!).
I am very pleased with the possibilities to change the input boards. Nice toy to play with.
Unusually I got the EDCOR-transformers first, then the pcbs, and still waiting for some
Nelson Pass, Mark Johnson, 6L6 and all other involved persons...
Greets from Germany
So glad I tackled this kit! The last kit I built was over a decade ago when my fingers were more nimble, and my EYES were so much better. But, with the help of a magnifier on a stand, and lots of light, this kit went together in a couple of evenings after work. A fun project, AND I have a beautiful sounding amp! Looking forward to breaking out my pre-amp, bookshelf speakers, and turntable!
It was my first try as a DIY amp builder and it was a thrill. The set up you guys ( diyaudio ) have put up here is just perfect. From the available literature, the forum and members inputs, the anticipation, the neat package, even the little plastic bags where the parts were shipped in; quality stuff. And what to say about the build guide put up by 6L6, that made assembling this kit a breeze.
I really enjoyed it.
The kit resulted in a quality amplifier ( I have bought two ) with a sound to match.
They are still under "trial" because, I must admit, my system is not easy for them. They are kind of struggling to power up my 4 Ohm SMGA maggies... my TL12 tube LEAKs were more at ease.
For reference I am using a Benchmark DAC1 HDR as pre amp, and the ACA with a parallel input and a Y cable.
As I said I really enjoyed the whole process and seriously considering building another. Maybe the Aleph J!
Thank you guys very much
This is the first DIY amp I've built (well, first 2 actually, since I bought 2 kits). This package, with all needed parts, a well built chassis, labeled PCB, and clear step-by-step instructions, is a good confidence builder. For example, while I have soldered before, I had never soldered anything to a through-hole board (that will be immediately obvious in my pic below). This was a good opportunity to learn a little and work on that skill.
The amps fired right up, and look great. The chassis is especially nice, considering the price. Sound-wise, they are not bad at all, and capture a nice bit of the single-ended class A "magic". I am quite impressed by the flexibility (stereo vs mono, RC and XLR input) and have experimented with all 4 operation modes. Each sounds a bit different and none are perfect, but the sound far, FAR exceeds what it should at this price range and a hack like me doing assembly. To me, this was the perfect price point/time investment to sample solid state class A and learn a bit about how amps work at the same time.
I am a single ended triode fan. I have a DIY pair of speakers consisting of an Altec 515b, Altec 755a and RAAL dipole ribbon tweeter. I tri-amp the speakers using three 45 SET amps, one of which I built myself. One of them is a Korneff if you know who that is. They all sound very much alike because they are all based on the same circuit. I bought the ACA out of curiosity, wondering what a single ended transistor amp sounded like. The short answer is very much like a SET, it must be the single ended Class-A part of amplification I like, not necessarily the fact that they are tubed.
The Korneff is considered one of the best 45 based amplifiers. The 45 tube is very special compared to other SET tubes, even the venerable 300b. It is also very low powered at 2 watts. I was having problems with my 755a midranges, thinking perhaps my 61 year old drivers were finally shot, I was hearing significant amounts of distortion. I thought the coils were rubbing. I called Great Plains Audio, a specialist in Altec speakers, and the tech told me how to test for rubbing. I used this amp for the test, and I found out my speakers were fine. I discovered the problem was that the 755a is a 4 ohm speaker. None of my amps have a 4 ohm tap, and the amp was freaking out at the low impedance. My solution was to put the ACA in the system along side the 45 SETs. It blends in beautifully, and my distortion problem is gone. My opinion of this amp is; if you can deal with the low power, it is one of the best amps you can buy (build), and for the money it is incredible.
This was not my first project, but I am no DIY expert. This was easy to build and the finished product looks like a production amp.
As advertised...really cool that Mr. Pass would do this for the LX Mini crowd (and Mr. Linkwitz, RIP). Fun project, everything checked out and worked on first go, and sounds great. I may be hooked. Thinking about building another before golf season returns so that I can try with XLR, even if it's not particularly cost effective. Anyone need a miniDSP?
This is my first go, but this was an easy assembly, well packaged and manufactured case, nice finish and silkscreen work on back.
I built mono blocks & wasn't sure what to expect sound wise. they run pretty hot (class a), but every day the sound improves. I have been listening for 2 weeks now & will show them off tomorrow to another audiophile. they will never replace my big amps, but I am enjoying listening to them & even my wife is surprised how good they sound. I enjoyed building the kit & look forward to doing another diy project
wasn't sure what this would look like when ordering, but am very pleased with the quality of the amp chassis, not to mention heavier than I expected. the quality & looks fit right in in my big system
Very nicely finished chassis, with enough room inside to add some modifications to the stock ACA kit. Photo attached shows chassis with ClarityCap MR coupling caps and Audio Note electrolytics, bypassed with small-value ClarityCap MR.
Used with Monitor Audio Bronze 2 and driven by NwAVguy's O2/ODAC, this setup fills my newly, acoustically-improved kitchen/utility room with quality sound that my old ears haven't heard for ages. Only downside is that now I can hear how badly most studio recordings are made. Good quality live recordings sounds incredible, and so do voices and percussion from good studio recordings. Sometimes I'm lead to believe that the artists are sitting in a corner of the room, or in the next room. I'm almost back to the times of my loved Micro Seiki/SME/Ortofon/improved NAD/Tannoy 15" setup.
I have owned some expensive equipment. Krell KSP-7B, KSA-150 and a pair of Martin Logan Ascent i's. I have been downsizing for a while. A 95 pound amp was a bit much. As a 35 year FCC licensed electronic's tech the build was...well easy. I built a pair of the mono-block version, but the excellent instructions should make it easy for anyone. I wish tech manuals were written this well.
My Parasound P6 2.1 pre-amp finally arrived, so I hooked up the amps and set the pre-amp to drive my NHT Classic 3's at 80hz and above leaving the bass to the Sunfire Jr. How do they sound? Well I would describe them as silky smooth with all the detail air and space around the instruments as you could ask for. Everything just sounds right provided your source material is. Running a sub allows the volume to be more than needed even with relatively in-efficient speakers (NHT Classic 3's are 86db).
With minimal electronic skills you can build a pair of first class amps. An easy step into audiophile equipment at a remarkable price. Great stuff that you can't go wrong with. Absolutely recommended!
Reviewing the whole package here. I prepped by watching some videos on soldering and getting some practice parts, and the assembly of the kit went smoothly. As a first timer, it took me longer than the estimate, but I was being super careful. Chassis looks nice, though the LEDs are too bright. Now powering vintage Jansens Z960s in a big room with an Airplay/Mac source, and the sound is great. Clear and crisp, no flab in the middle. It'll go plenty loud, well above what my family wants to hear. Some distortion at the max volume on the computer, but it doesn't need to be pushed that high to be plenty loud. It is quite warm, as folks have said. Overall, it was a lot of fun to build and sounds great - I'm super pleased.
The service has been great; communication as well and the product is almost flawless if not for a slight trace error on the drain of Q5 that is easily fixed adding solder (if not detected the circuit still works unaffected until a certain load).
So overall thank you for a good service.
This is my second purchase of the ACA and I’m using them in bridged mono configuration. I’m a big Nelson Pass fan and this amp doesn’t disappoint. It’s a low power class A design and the sound is wonderful, especially considering the price. Everything about the kit is high quality, from the design to the packaging. Excellent communication from the DIY Store also. Highly recommended.
Works nicely as described with good degree of flexibility on output voltage and amperage capacities. Ended up using this fed by a 5V SMPS iFi, iPower supply to power a mac mini audio server SSD (bypassed the 5v sata ribbon cable feeds). Seems best for optimizing SMPS supplies and at least in my applications didn't match results up to that of the Mojo Illuminatti v2 which is considerably more expensive of course. So it's great for powering something on a separate line or supply providing greater noise isolation between components without breaking the bank. It definitely provides performance that's better than a generic 5V wall wart SMPS and improved the system sound post-iPower as well. Highly recommended device for the right application/situation.
My son and me build each an Whammy. Easy building, excellent sound. No trouble building them. After recieving the parts we spend xmas time together stuffing the beautyfull pcb. A instant-sound-project :)
I built the Pass DIY Sony VFET amp kit with this chassis and it turned out very nicely with drilling countersunk holes for the faceplate mounting screws and the two LEDs.
Top quality pcb DIY build instructions are excellent too. Great service - highly recommend