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Based on 843 reviews
4U Deluxe F5 plus handles

Chassis was a little expensive but if your doing an F5 you probably don't want to go smaller. Assembly was easy and the chassis look great and it's pretty much made for the Diyaudio boards. Rear panel has no center support and while it seams thick enough pushing on it too hard while inserting a power cord will bow it in so think about adding a brace. The predrilled front panel made mounting the handles easy. When assembled one of the handle bars was loose and the other fine so it may need a little shimming. That said I'm actually pretty happy with the chassis and would purchase again. Chassis arrived in California in 5 or 6 days.

A New Favorite

I have several other DIY headphone amps. This one has the most well behaved turn on and turn off transients, i.e. almost none. No worries about damaging delicate drivers. Whammy has absolutely gobs of gain without noise. It can easily drive even low sensitivity planar magnetic headphones. I'm on #2 of 5 different front end opamps that I bought to try out and the differences between #1 and #2, although subtle, are there for the listening due this very clean circuit design. DIY audio doesn't get any better than this.

Build includes switching HP jack, preamp output jacks, noise filtering IEC inlet, front panel power switch and LED. All easy to add, although the Hammond chassis does get a bit tight and parts layout a bit critical.

Super quiet and well behaved

I have 4 other DIY headphone amps and this one is the quietest and has the most well behaved power turn on and turn off characteristics. I surmise that's due to its excellent internal power supply. The circuit has gobs of gain, enough to drive even my low sensitivity planar magnetic headphones. I added a 2 amp noise filtered IEC inlet, power switch/LED and output jacks to the original design. This unit functions well as a preamp, quite beyond my expectations. The new heart of my desktop system.

It was time for a BA-1

Fantastic pcb! Top quality! Very fast delivery around the world (USA-Germany) in under
one week.
I found a pair of TOSHIBA 2SJ109 and I thought I should build a BA-1 poweramp with the
singleended follower. Not finished yet. Intake board is done.


Great sound

Very happy with my amp camp.
I bought the aca 1.6 kit as my first project, it was straight forward to put together.
It sounds fantastic, very smooth. I use it with 8ohm 88db 3 way speakers, the sound good but miss tight bass, nevertheless the midrange and highs are fantastic and non-fatiguing.
I am going to build the M2X to have some more power.
The aca is definitely a keeper, also it dissipates 40watt vs the 160watt of the m2x, so useful for the hot summers.

It was time to build a BA-1

I found a pair of original TOSHIBA 2SJ109 BL - I was searching for a long time.
Now it was time to start this build.
The BA-1 - pcb is of excellent quality. Delivery was extremely fast as well customs.
The fun starts now....
Can´t tell anything about the sound - not finished ;-)

Coming from the Heathkit, Dynaco and Hafler kits generation, building this kit was an easy and fun project. The build instructions and step by step layout was easy to follow. For the diy person there's no better enjoyment than to build your own great sounding audio gear. This Amp Camp Amp is a very clean sounding amp, you will not be disappointed

Nutubes are versatile and sound great

I have built two nutube pre amps balanced one in a Galaxy 1U chassis, and one single-ended one built into an ACA chassis to make a Pass DIY integrated. Both of them sound really good and construction was straightforward with no problems except the third time I fitted a Nutube to its circuit board the little legs just didnt want to go into the little holes on the board. I used 3mm Sorbothane sheet to stick the nutube to the board and I have not noticed any microphonic effects. Good job, Nelson and DIYaudio ( thanks to 6L6 for the build guide also )

Lx-mini ASP

Great kit. Easy to put together. Works great with my vinyl player.

ACA v1.6 build

Went together beautifully, instructions were great, sounds wonderful.

I built one. Thank you Herb Reichert!!!!!!

I've always been intrigued by 300B SET amps. Over the years I've built a number of kits from AudioNote Kits and Bottlehead. Herb's Stereophile review made me commit. This is the best packed, picked, instructed kit I have made. Like Herb's, mine is the upgraded version, but I built it myself. It was an easy and fun build. My only caution is for newbies with little soldering experience. Watch some YouTube videos and practice first. In places the PCB is densely populated and the solder pads are close together.

Now for the best part. As Herb stated in his review, pair the TU-8600R with the right speaks and they sing. It's just mind boggling. You just built a $20,000 amp $2,000. There's nothing else to say!!!!!!

Beautiful and satisfying kit

This is my third DiyAudio build, and it was a great experience. I did the stuffing of the PCP over two shorter sessions over days, then final assembly during a third build session. No issues at all with kit and build. Teamed with the ACA I built last summer it is the best sounding desktop/computer system I have ever heard.

Another satisfying diyAudio project

I bought this little amp for the tube novelty and as a companion to my Amp Camp Amp. It was a fun and easy build which I spread over two days (approx 6 hours). The online documentation was great as always and I can highly recommend this wonderful little pre-amp. Quality parts and quality performance. My only "glitch" was the push button on/off switch rubbing a bit on the chassis hole but some minor adjustments had it freed up in no time. The picture was taken during initial testing.

Beautiful sounding B1 KORG NUTUBE

The pcb is of very good quality. The diyAudioshop sent it very fast. Included JFETs are matched very well.
How does it sound? - Beautiful! Absolutely no hum or noise. Open wide soundstage. Interesting possibility
to adjust positive and negative 2nd harmonic. Together with my BA-3 poweramp great.
This little soundmachine is a giant!
Dirk / cubicincher


This preamp looks so tiny - but the sound is giant!
The pcb is of excellent quality, as well the matched JFETs. I would say it is not difficult to build.
Delivery time from diyAudiostore was very fast. Well packed.
How does it sound? - Fantastic! The possibilty to adjust the harmonic profile is a very cool gimmick.
Build it - Test it - Enjoy beautiful music with it!
Plays wonderful with my BA-3 poweramp and others.

Easy to build, sounds great!

I've more than 30 years experience listening to Hi-End equipment, but I hardly found a solid state amplifier that's cheap enough and sound that good, the greatest part of this amplifier is simple, though the output just 5W (24V power supply, stereo), but it can drive my Totem Rainmaker (4 Ohm) with quality sound, and less than 10 hours after I finished the construction! I'm no good in circuit reading and complex wiring, but I'd manage to make this within one day and the bias adjust is easy! Highly recommend for anyone love quality sound!

I love this little amp that could!

At long last, and after 3 iterations, I’m reviewing my ACA 1.6.

I bought one complete kit plus an additional kit not including the chassis and power supply. Being new to DIY audio, I built the first kit exactly per 6L6’s excellent instructions. It went without a hitch and was a ton of fun to build. Any downsides? I wasn’t happy with my (really) old speakers with the ACA and I went shopping for something that would work better.

I ended up with (to my own surprise) a set of B&W CM5 S2’s and wow! What an amazing little amp! Such a lively, fun, clean sound! After years with music as a sideline affair, I’ve finally re-discovered my passion!

It had been my plan to use the second ACA kit (and much more heatsink) to create a bridged (approx) 15 watt amp. After living with the “Stock” amp for a couple of months and reading some of Nelson Pass’s writing on the subject, I decided to to use the second kit to bi-amp my speakers instead.

So, another power supply, much more heatsink, and 2 iterations later, I’m thrilled to say that my 4 individual amplifiers, in a cabinet of my own making, are powering a pair of bookshelf speakers in a way that I never dreamed possible from such low power and such small speakers.

It really is the first watt that matters most!

And the support here at DIYAudio is amazing! So much knowledge…

I can’t thank you all enough for helping me experience music again this way!

F6 vs F5

I decided to build the F6 after doing and listening to the F5 for a few months. Although the F5 is a fantastic sounding amp I somehow found it a tick too bright and flashy...
Now the F6 seems to be a completely different beast (in a positive way) as it sounds darker and rounder.
Only a few hours of listening but I guess I'll stick to this one ;-)
Absolutely fantastic service from DIY as always.

Whammy in Modushop Galaxy enclosure

Building the Whammy kit was straightforward with only one operator error around the three regulator strategies..if the preferred one is LED regulation, that should ideally be the first one outlined in the Guide. Its a small point and Jim ( 6L6 ) was kind enough to message and Facetime so we sorted it out very quickly. He also suggested a simple to wire the kit for a pre-amp output using a switched phone socket and how to get a Blue LED power on connection from the board. Very helpful

I built the board into a Modushop Galaxy 1 U 230 x 230 / steel cover / 10mm faceplate enclosure ( see pix ) That gave plenty of space for the mains connector and space to fit a bigger phone connector. Ideally the faceplate would be machined to fit the pot and socket which are both designed for thinner faceplates. I made a little sub panel to carry both items and the power on LED., as well as lining up all three items on the centerline of the fascia ( a bit obsessional I know ) This was acheived by using a 3mm spacer strip between both the top and bottom panels and the case sides. Combined with the thinner steel covers that gave just enough clearance for the board and components. If the covers were made with the slots above the regulator heat sinks cooling would be improved but I havent noticed any problems. Jim was a bit concerned about the screening afforded by a case with no continuity of grounding between the panels but any noise is below my tinnitus level so I dont perceive a problem! The use of the Galaxy case gives a good visual continuity between Whammy and my integrated ACA and Monoblocks...all it really needs is the cool Pass logo from the ACA.

Nelson Pass Amp Camp Amp kit

I bought this amp to test Paul Klipsch statement that all he needed was a great 5 watt amplifier to drive his Klipschorns. I will attest that this amplifier does to job extremely well. Great kit. This is my second build of a Nelson Pass amp. I built a First Watt F5 several years ago to compare it to my Harmon Kardon Citation II. All three amps are sound fantastic.

Giant killer

What a fantastic amp! Easy to build (the trickiest part was prepping the chassis - I didn't purchase the diyaudiostore chassis, see NZ import duty legislation, but that's another story). The sound with a B1 buffer preamp and a pair of full range Markaudio Alpair 7s is magical. A perfect balance between detail and ease of listening - a very well mannered amp. With said speakers the amp runs out of steam a bit; I'll purchase another kit and convert to a pair of mono blocks.

I have listened to very expensive systems that don't afford any more listening pleasure than this.

Great Nelson Amp

Bought and built amp to prove Paul Klipsch theory that all he needs is a good 5 watt amp to drive his Klipschorns. This Nelson amp is fantastic, does the job be yond expectation. Is a great addition to my home built F5 amp and Harmon Kardon Citation II refurbished amp. All three sound great. Are using amp as we write this review. Nice kit build. Questioned the solid wire and suggested that the transistors be labeled better for identification. Another great Nelson Pass low power amp.

Beautiful design and working very well

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.

M2X - boards are great!

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
other parts.
Thanks to
Nelson Pass, Mark Johnson, 6L6 and all other involved persons...

Greets from Germany

lovely experience

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