WHAMMY HP amp question

Anybody listened to one? Designed by Wayne Colburn of Pass Labs. Looking for sound comparisons to other amps. Or just general feedback on sound quality. Thanks.


I just finished building one, initial impression is very positive, I’d take it over my Jotenheim, or the THX I’ve heard. Where it shines is in dynamics and tonality.
It’ll also drive pretty much anything, I pulled out my T50 RP2’s and it’s more than loud enough for me at 11:00 on the volume dial.
It’s a very good sounding SS amp.
I need to listen some more before giving a full impression.


Thanks. What case did you use?


The board is designed to fit it. You will need to ensure you have the tools necessary to cut out the opening for the IEC socket. The only hole that needs to be drilled precisely is the one for the volume pot, you have a fair amount of leeway in everything else.


Right on. Thanks for the heads up.

Is there an option for adding an led to the front panel to indicate the unit is on?

It’s kit, you can easily add one, just an LED and appropriate load resistor. There is an LED in the PSU circuit providing a voltage offset, you could stick that on a front panel. But I would add an additional one, rather than relocating the one in the PSU.

Rob very good of you to get back to me so quickly. I was just looking at this on DIY audio after I posted. I would rather not locate either of LEDs D5/D6 to the front panel. I agree with you that a seperate spur would be better. As far as I can see from the circuit diagrame the secondry on the transformer is 22V AC (28 unloaded). Is there a logical/obvious spot on the circuit board to pick up a DC spur to attach and LED and appropriate resistor?

Thanks for your advice on this.


PS I have just ordered the kit hence the questions

I didn’t bother with an LED, as far as I can see you have basically 2 options, either pick up the DC at some point in the circuit, mines at about 16.5V give or take, or probably better drive it off the secondary coil directly, there is a simple circuit here to do that, you could either build it on a piece or veroboard, or dead bug wire it.

The advantage of coming off the secondary is it’ll actually turn on and off relatively quickly.

Figured I’d chime in here since there are new posts. I’m currently auditioning 5 different op amps. I’m doing initial impressions during the first 2.5 days of use of each. In about 8 days I’ll post my initial impressions. After that I’ll do some longer term listening just to make sure I’ve given each amp enough time to bake properly.

Right off the bat though, I started auditioning different op amps because I’m not happy with the 4580 that comes in the kit. It’s pretty dull/lifeless to me. I’ve already listened to 2 other models that I like better but I don’t know what models they are - I’ve covered the model numbers with tape and labeled them with numbers 1-5 so as to not allow any bias to dictate what I’m hearing. I’ll remove the tape and find out what’s what after I’m done with my long term listening.

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Oh and regarding the LED, you don’t really need it if you’re close. It’s a class A amp so it will be hot if it’s on. Also there really is no reason to ever turn an amp off. But to each his own. Good luck and enjoy the build!

FWIW I’d say it took about a week for my amp to sound like it sounds now.
I just leave mine on, it takes forever to hit operating temperature, and I’m too lazy to wait.
As I mentioned above I swapped the 4580 with a Burson Classic V6, I prefer the Classic, enough to maybe pick up a Vivid, but it’s not night and day.
Interested in your take on the op amps.

Alright, I’ve now had 2.5 days on all op amps except the default RC4580 with has about 3 weeks on it. Here are my very general notes in order of most to least favorite. Your mileage may vary.

OPA2134PA - It’s open, lively. Good bass. Good detail. Best so far. Good dynamics. Spacious.
OPA2107AP - Good bass. Spacious. Good attack. Good detail, texture.
OPA2228PA - Decent top end. More lively than 4580. Bass lacking.
RC4580 - Dull, lifeless, no dynamics.
AD823 - Not feeling it. lifeless. tired. don’t want to listen to it. dirty. constipated.

Will give them all more extended listening and update if my thoughts change.

For reference, I’m using Audirvana on a Mac and a Cambridge CXC transport. Dac is a Bifrost Multibit, HPs are HD600 and ATH-M40x. All connections are Audioquest.

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Thank you for your advice on this. I have the hammond case so a take off from the secondary will I guess have to be routed under the board and maybe pop up through one of the unused stand off openings at the front.



Many Thanks for your thoughs. The LED is really more for the aesthetics and to balance the front panel up a bit but I hear what you say.