built it over 2 easy days. worked straight after the build, no issues.

Its rocking an audio technica M20X for now, (a very very economy phone, but one which has run-in atleast 1000 hours as a training e-drum monitor).
this amp has become a motivation to audition few headphones. it deserves much better than what I have now.

Also, was pleasantly surprised how well it drove my (bridged) pair of Amp camp amps and my DIY horn speakers.

the kit did not come with:
Pre-out RCA sockets, even though the back panel is drilled out for the same, and the shielded cable length provided for.
A resistor for the blue power LED
not an issue except for needing to run to the local parts store.

I will be trying out a few opamps with this . including the burson discreet v6.

Thank you Wayne,
more karma points to you. I am a very happy user.

A fun build, sounds absolutely awesome as a headphone amp and just as great as a pre-amp.
The original build guide was a great help.

Beautiful kit and definitely highly recommended!!!

Many thanks to Wayne for making this design available to us and the Diyaudio store guys for putting an awesome kit together.

Easy to construct, well designed PCB and high quality parts used and the result is a superb headphone amp.
Amazing detail and dynamic range, wide open sound stage, neutral sounding.
It is not the most compact headphone amp but what you loose in desktop space you gain in sound quality and enjoyment listening to your favourite artists and albums all over again.
This headphone amp has tonnes of power available and can drive virtually all headphones to insanely loud levels. Tested with a range of headphones from Sennheiser, Beyer Dynamic and Audeze and they all sound amazing through this amp.
You won't want to take your headphones off after listening to this amp.

This is the third amplifier I have build and I'm really happy with how it turned out. I went to the trouble of integrating a Khadas Tone Board DAC so it could be used as an "all in one" solution for my desk at work. It sounds great with my HD6XX and was a lot of fun to build. You can see more details about my build here. www.jeremyyoungdesign.com
Thanks Wayne!

A friend of mine trigged me into headphone listening. It is wonderful to be able to listen and enjoy music in the evening at real listening level.
I am a great Pass / Colburn fan and falling across the Whammy I of cause had to give it a try.
Recently I borrowed a set of Hifiman HA1000SE – whee this headphone and the Whammy really is capable putting my HD800 to the wall at a level I have not heard for a headphone before.
Very detailed dynamic sound with energy and nerve I love. It really reveals every change done in my set-up.
To bring it to best possible level I additionally used pure silver wiring, pure copper RCA connector, Jantzen Silver/Gold ac coupling capacitor, copper plates/mica underneath the output transistors, copper alloy screws, OP627 op-amp, Wima MKP10, some extra decoupling, silver solder lead and a 20Kohm 24 pole Elma shunt attenuator.
Being proud of having additional Pass Gear and to honor Wayne I used a look alike chassis – gave up using the heat sink sides.
For now it´s running 40mA bias – I have no clue how much extra performance can be gained by higher levels.
My friend with the HA1000SE is in process of building a tube-based headamp and I can´t wait to compare the amps.
Cool to be able to build something like this.
Hi from Denmark and thanks everybody for contributing to this nice project – reading the very long tread was really inspiring.

It was my first DIY project and fortunately it was successful. I haven’t killed myself working with mains and very glad about that =) Some patience and accuracy is rewarded by incredible sound, depth and wide soundstage. Built with AD823ANZ and am more than satisfied with SQ – very precise, detailed but pleasant for log-time listening. I will upgrade it to discrete OpAmp – probably with Sparkos Labs’ Dual Discrete Op Amp SS3602 – very excited about that.
I believe that there was no red 0.1uF film cap (between RCA GND and safety earth) listed on the BOM on the Project’s Thread (or I have missed that), so be aware to order it. I can not see any issues without this cap, but if Wayne suggests to put it – we should… If you are using Hammond enclosure 2,028” (51,51mm) high – DON’T choose filter caps higher than 35,5mm. 40mm is too high and they don’t fit – need to replace mine =(
Many thanks to Wayne and the Community for a grate opportunity to built such a gorgeous headphone amp.

I never really built anything before. Started off with a pair of Amp Camp amps in January. That went so well, I decided to build the Whammy headphone amp. Biggest challenge for me was to order all of the parts because the kit was sold out and I just didn't want to wait. It actually turned out to be fun and easy to track everything down
Listening to the Whammy right now. It sounds great. Dead quiet. I used a socket for the op amp so I could try different op amps out. This is really a little too geeky at the end of the day as it is hard to compare. They all sound bad when you first plug them in and change drastically after an hour or so. So far I've tried the RC4580, which sounded ok. Switched out to the OPA2134PA, which after some burn in time seems to be a little less bright. Nothing drastic. Anyway, a great project. Highly recommended.

Very good service regarding shipping, communication and documentation.
Built several SE - regular - and my flaggship combining 2 Whammy to a differential headamp.
I used 2x 2 OPA627 with amazing results. Anyway, the concept offers many different options or you stick with the standard, which is also great. Highly recommended!
I use the differential Whammy with Sennheiser HD800S. The SE with Focal Clear.
Thank you Wayne Colburn for the concept, 6l6 for the build guide and the diyaudio community for the inspiring infos!