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Based on 2034 reviews
So Great!

I couldn't be happier. The kit is awesome. The support is great. And the sound? Fantastic.

great quality and support

I was impressed with this pre-amp from the get go. Both as a kit and as a component in my sun room. Intriguing visuals, really good sound and "I built it" as a bonus. One of the best quality kits I have done in the recent past, and easy assembly and support.

Great Job to the team for all their work

Inexpensive kit makes great sound

Sound is big on my 95db sensitive speakers.nice sounding.
No complaints.

Manus H.
Great sound from an easy build!

Building and finishing the case was much harder the building the electronics. Easy to build for even a novice like mem using the standard bill of materials. Worked first time with no noise at all, even at full volume. Upgraded the op-amp already, with impressive results. Drives my Audeze LCD-X very well. I am really very happy with my decision to build this and the sound quality of the final result. The case it not too bad either!

Front End 2022

Transparent, detailed gain without sterility. I would call it top notch to enhance without detraction or subtraction from virtues of the amp stage.

Single ended usage @ 36v, used with Pass DIY Sony single ended SK60 VFET, superb.

Epic sound

As bridged monoblocks they have the best sound ive heard to date in my system. instrument detail , stereo image in vinyl has exeeded all my expectations and the overall sound is beautifull, gives you a smile. Totaly recomend it and will buy again to build for friends

Oh happy Day

This is my first complete kit, I've made.
- Full ACA mini kit and binding posts from the store
- diyaudio fire metal solder
- Araldit standard
- Ohmmite Heatsinks (8 x VM1-038-1AE)
- Aluminium plate (dimensions 250 x 190 x 15mm)
- Some small material
The amplifier sounds wonderful and it will be used with 6 x 9inch and 12inch full range speakers (another one is planned:-)). The adjustment for biasing was a little time-consuming but at the end it's a very nice experience.
(see my post #2,255 at the ACA mini thread)

Great DIY Project and Great Sound

One of the really nice things about Pete Millett's Starving Student II amplifier is that you literally get everything you need to build it except the solder. It's an easy build, and when you are done, you have a headphone amp/preamp that sounds great and looks like a commercially made product. It has no issue whatsoever driving the Sennheiser HD650. Highly recommended!

Dalton L.
F5 Turbo V2 - An Alaskan Amp!

A wonderfully designed amplifier! These PCBs are easy to solder, feature clear writing and proper spacing. The circuit is easy to assemble with some patience- follow the guide/watch NocturneVid66's assembly videos, and you're off to a great start!

This build is a dual mono (common star ground) in a 500mm dissipante chassis. Biased to 340mV, it runs at approximately 114 degrees F while never exceeding 10mV of offset across either channel. I highly recommend the available thermal pads from the site as well!! I chose to cassacode as well as put caps on the output boards. Cassacode if your needs demand it, skip the caps unless you have HF osculation. Power caps are 22,000uF x 16 = 352,000uF total at 63v rails; all wire is oversized, and I soldered screw-down wire terminals for connections between boards.


I made mono blocks with the superb pcb you are selling and the fets.
i am astonished by the results. they have only few hours and they start to open up!
Thanks Mister Pass and DIY audio store, what you do is revolutionnary.

Superb sounding amp

I've built it with 32V rail and 0.47ohm source resistors this does produce a lot of heat. Make sure you use big heat sinks with this combo. This amp sounds really good with ACP+ or Wayne's 2018 Linestage, clean, detailed and musical. It has no issue driving a pair of Boland Accoustic BTX180 made by Peter Boland of NZ. These are 4 ohm demanding speakers but the amp drives them effortlessly.

Amp Camp Amp
Steve M.
Fun little amp!!

First and foremost, this is a nice little project! That being said there were a couple of small issues I ran into. First, two of the resistors were the incorrect size. I dug out some correct ones from my stash, not a big deal. Secondly, the instructions were sometimes difficult to follow. For example making the back panel power bus, I soldered it to all three terminals before reading "do not solder to speaker terminals yet". Maybe I was in a hurry, but I had to unsolder and redo that bus like 6 times. Read all the way through each section before soldering anything. I also had to redo the enclosure to heatsink mounting a few times to make sure everything fit without touching. It's entirely possible that my excitement got the best of me, and I got ahead of myself (normal occurrence). After all is said and done, this is a fun little amp. It definitely does not have the power reserves that my Yamaha M-80 has, but it can drive my Cornscala's (6 ohms) to reasonable levels, and sounds pretty good doing it! I will soon be trying the mono mode, when a friend brings his ACA over for a listening session. I have high hopes for that as well. I would definitely build another one, given the chance.

Aleph J
Emmett R.
Aleph J Finished and Impressive

I just completed my build and testing of the Aleph J amplifier. It’s occupying the 4U chassis of the F6 amplifier I built and have been enjoying for the past 18 months. I liked the F6 a bunch, but at times I wished for more authority over my speakers. The Aleph J certainly has that! It sounds great. It’s detailed, has a nice soundstage, and packs a punch. So far I’ve tested it with B&W 686 S2’s and a vintage pair of ADS 1230L’s. The Aleph boards were top notch, and the build guide was very helpful. I’m grateful to the DIY Audio forum for for the great service and products it provides! Keep up the good work:-)

Amazing ACA mini June 2023

Once again the ACA mini as a kit with essential kit components
At all documentation descriptions 5 stars ⭐️ ⭐️⭐️⭐️⭐️

Pesante 2U
George A.
Quality Chassis

The Pesante 2U is a professional looking chassis. Used for three way active crossover. The price to performance is exceptional.

Superb DIY Active XO

Two boards were used for tri-amp crossover; low pass, bandpass, and high pass. What I am hearing is its excellence at what it doesn’t do, no sonic signature or smearing that can be experienced even with well implemented op amps. It performs its function divided audio frequencies to amps without adding or subtracting information from signal. Really happy with this xo.

Amp Camp Amp
Andrew C.
Fun, Fast, Quality Sound

Recommended. It went by quick. I'm burning the amp in to the Grateful Dead as I write. Very surprised and pleased the sound quality, loudness, and bass. Build hints: 1) Read 1.6 (board build) and separate 1.8 (wiring only) instructions end-to-end first including helpful comments. 2) Brush up on soldering technique 3) Would be nice to get a chart listing wire count and length but plenty wire supplied. It worked first time. Easy peasy.

Effective SMPS filter

Thanks to the excellent filter my FE2022 build is exceptionally quiet, which enhances its ability to capture fine details, N + THD < -90dB with 48V SMPS.
Many thanks to Mark and diyStore.

Great sounding frontend

The FE2022 impresses me in four ways:
1. It has a balanced frequency response, reaching deeper lows without an excessive emphasis on upper bass. It also maintains a flat response in the presence and super high-frequency regions.
2. My build is exceptionally quiet, which enhances its ability to capture fine details, N + THD < -90dB with 48V SMPS
3. It shines in creating a realistic soundstage, with a black background that allows the sounds to stand out with clarity and precision.
4. Last but not least, it has a wide volume control range from 0 to 80 steps, making it highly functional. This is visually displayed and realized with an 10k APLS potentiometer. My build has max gain limited to 6dB, with R3 = R4 = 20k

Great little monster

I’ve build this amp over the past weeks, sourcing the PCB kit from DIY Audio store and the other parts from DigiKey and other sources. The parts kit was sold out at the time.
I bought a LRS 100-24 to embed the power supply in the total package and used an SMPS DC filter because off the good reviews. Based on what I hear, it certainly doesn’t hurt.

I have 2 ACAs that I use in bridged mono and everyone knows (or can read) what that delivers in sound quality.
I’m therefore so happily surprised about the sound quality off this little amp. In certain ways, it delivers more details or maybe dynamics than the ACAs do.
I would have to do more listening sessions switching back and forth to know. But not doing that right now. Just enjoying what I hear :)

ACP+. What a great preamp!

I’m thoroughly pleased with this kit. The package included everything that I needed and It went together with great ease. It sounds fantastic! This has given me the opportunity build on my soldering experience gained in building the 6-24 crossover. I actually combined both in the same enclosure. I now have the ability to drive the 6-24 crossover with the ACP+ and with the rotation of a selector knobs can route the output of the preamp to a full range amp /speaker set up. This has made for a super cool project, a great learning experience and quite a confidence booster. Thank you Nelson Pass for designing such wonderful audio equipment and user 6L6 for creating such great and easy to follow build guides and all the other helpful members at I’m gearing up my next build, the Aleph J. I hope to be back with another review when I’m done that one.


Simple device that works great. It was a quick and fun to assemble. It really enhances the overall sound quality.

Mark P.

Looks and sounds incredible. The kit is no longer available, so I had to source the parts from several different suppliers. I highly recommend this amplifier. Thanks Nelson and DIY Audio.

RK27 Breakout PCB

This pc board is a perfect solution for helping prevent heat and mechanical damage to the potentiometer. The board provides either screw down wire clamps and direct soldier of the wires to the pcb,

ACA Mini Completion Kit
Ranganathan D.
Amazing range of frequencies!

Without any formal knowledge, extended experience or measuring instruments, my impressions are that this little amplifier reaches way lower in the bass region as well as the high frequencies without a roll off. The sound is full and complete. I am excited anticipating how it will sound after some use. The kit is simple and easy to build. Would suggest two multimeters for the biasing - makes it easier. The kit was flawless (as always), the build guide by 6L6 was excellent and we must thank Nelson Pass for his generosity to all of us. If you are thinking about building this amplifier, please don't hesitate! Highly recommended!