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Based on 776 reviews
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!!!!!!

Perfect specification

I have measured the gain and the matching is perfect

I will use the pair for F5 and be impatient to see the final result.
I'm very optimistic.

Very good

Everything perfect!

fast shipping, great packaging, product as expected! well done!

Replacement panel

Jason was extremely helpful and accommodating in facilitating a replacement panel that I had ruined during fabrication. He went the extra yard for me
Thank you

Merci pour votre professionnalisme et votre assiduité!


Nice boards, easy build

Nice to have always available

I bought many of them in the past years and I always want to have some spares in my lab. They are really great isolators, easy to use and with impressive performance.

Nice PCBs with matched JFETs

The PCBs look really well done and matched JFETs directly from Nelson Pass make this kit unique.

I bought this board because I know that I can TRUST this circuit. I know who participated in this design, so I can be confident. Also, this is not a copy, there are no mistakes, you know that all values are correct and the layout is well done. The board itself is a piece of quality. I would prefer bigger pads, gold contacts and more space, but it's ok. Once the parts are sodered, it is not a good idea to remove and resolder better ones. So choose the parts you love the best from the beginning and keep it that way. It was not difficult to soIder those wonderful 1000uF/25v Silmics. They could not have one more mm diameter. Kaisei woudn't be welcomed here. I'm glad it was possible. I did not hear this buffer yet, because I still have to order the Nutubes, but I believe that it will be even better than the famous "K Buffer" that I like so much. I'll "see" it later! If I can post another feedback, I will write about my listening impressions and if it is better than the KB - for me... I'll send photos too. Thanks to the gentlemen who designed it and allowed us to have it so easily! Francisco

What a blast!

The WHAMMY was my first DIY project. The build guides are excellent, and the folks on the forum are extremely gracious. I enjoyed the build process and the finished amp so much that I got three additional kits for friends and hosted a "build party". We're all thrilled. The WHAMMY offers versatility for folks that know the circuit and want to experiment with their own mods along with allowing a complete novice like me to follow a clear set of instructions and learn the basics. As a DIY project, I give it 5 stars. As a finished headphone amp, I give it 5 stars for sound quality.

Thanks to DIYAudio, Wayne, and the community (special thanks to @6L6) for putting it out there and supporting DIY. I'm hooked.

My new pre-amp

This is a great preamp case. I got it to match my F6 amp case and to house my B1 Buffer with Korg Triode PCB + Fairchild JFETs kit. Also from the DIY Audio Store. It is still in process, but going together well. Superb circuit board. Really like the 12mm think front plate, has a real excessive hi-end look. All the panels are fitting together well. Super happy with it.

Good piece

Went together perfectly. Sturdy, perfect condition, packed great. Would order again.

F-5 Transistors

Yes, then F-5 transistors have been received and PCB came a little earlier, so now is the time to collect the rest of the necessary components. But the summertime that comes now makes the Diy activity go down a bit.

Korg Nutube

The Dual Triode have arrived to me in Norway, and waiting for PCB With some Components :)

Great little pre/headphone amp.

I bought two of them and have only assembled one at this point. They are from batch one so yes the solder pads for some of the components required me to put on my strong glasses and inspect with a magnifier. I have only used it as a pre-amp driving a pair of ACA running as monoblocks. The sound is very clean and neutral in this combination. As noted in the online build guide getting the board to fit into the front plate of the chassis can be a bit tricky but with some patience and gentle persuasion it will all fit. Build time was about four hours for me start to finish. When building the second one I may try fitting film capacitors in place of the provided capacitors 1 & 2 if space permits even if I need to go with a lower value as I am not a headphones guy. Overall I give it high marks and am interested to here if anyone has tried it with a linear power supply.

Great headphone/pre amp

The quality of the kit is great and the sound is surprisingly good. I am more than happy with a successful build.

SilentSwitcher works perfectly

SilentSwitcher works perfectly.
I use it to power DAC, battery and SilentSwitcher sound better than low noise linear power.

Great satisfaction

Perfectly designed PCB
Easy to incorporate parts
fair price
Great thanks

SSII HP Amp & Preamp

This is a potentially very satisfying project to undertake. The amp kit came with all the needed parts neatly packed in labeled bags. There was a parts lists, with pictures, and a schematic included. The PCB is of very high quality and it has labels for all the parts to be mounted.
With due attention, the assembly is not difficult, and the end result is very satisfying. The sound is somehow tubey, very clear and authoritative throughout the range. I’m using it as a preamp for another of P. Millett’s creations, the engineer’s amp, it’s a very nice match and it plays great all different kinds of music and sounds (I have synths attached to the system). I will recommend the project to all who feel they can do it. If you set yourself up to it, and you are careful and methodic, you certainly can do it!

Very nice unit

I got one of the 1st batch of kits - pretty easy assembly (with one caveat - see below) - which means that it was very well thought out & designed. Fits perfectly into the enclosure, which was also very well designed. Coupled with the ACA (which is then driving a pair of Klipsch Cornwall speakers) results in excellent sound - really shows off what the ACA can do.

I recommend this kit hightly for anyone considering it.

The assembly caveat - the 1st run of PCBs had some very small pads for soldering & my soldering iron had an old, beat up tip. Apparently, I didn't get all of the connections right (had to take it back to the bench a few times). The solder pads on the ground plane were the most problematic. After updating the soldering station to something newer than 30 years old, I reflowed all the solder joints and have had no issues since. I've heard that the 2nd release of the kit has a redesigned PCB, with larger pads, which would take care of this problem.

Easy, afffordable and great sounding headphone/pre-amp

Soldered up the whole board in a few hours, detailed instructions, couldn't be easier. High quality board as always from diy audio. This time I didn't have to de-solder anything, but past experience has proved that the boards from DIYaudio can withstand desoldering without damage.

Sounds great from first second used for headphones and as a preamp. I'm powering my ACA with it and it sounds great right away. I've not had any tube equipment before, but I'm really liking it, it sounds distinctly different from my solid state pre-amps. I didn't know it but I guess I like tube amps.

This was a quick and easy build, easier than the ACA, as all the components are through hole. there is no wiring at all.

Only suggestion I have is to mill holes on the bottom so that you can access the jumpers for changing between constant current and resistive load. It would just need to be big enough to slip a needle nose plier into.

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.

Fast delivery!

F5t v3

I'm building a pair of mono block F5t v3 balanced amps, I bought two sets of the soft start and speaker protection pc boards. With a 800 va 36v secondary torroids, the soft start I felt was a requirement. The speaker protection boards I wasn't going to use until several people explained the DC coupled amps can destroy my speakers if DC leaked to the outputs. The only interface with the audio signal is through the relays so no big deal. I'm glad they are sold together. Thank you diy!

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.