C2CElectronics Black Eye

[drew.spriggs]

Had a guy bugging me for weeks about building him a tube preamp/distortion pedal, and to my absolute shock he actually paid once I steered him towards this! Using one of the C2CE PCB's, and a pair of Shuguang 7025s (probably the best new, non-stupidly priced 12A*7 variants I've found).

B+ is around 280v, and uses the Nixie SMPS design (with the couple of mods I've used previously). Low-ripple caps, better quality inductors (not in the image; changed them over once my Mouser order finally arrived) and much better MOSFETS than the original means it's very quiet, and stays very cool. Added in a bit more venting than on the original to make sure it gets some airflow.

Tayda powdercoated enclosure (accidentally got gloss instead of matte, but oh well), Cricut vinyl decals and a couple of coats of matte clear on top. I still hate painting clear as I'm not set up to do it cleanly, but all things considering it turned out pretty well (there's one speck of dust next to the E in eye, but the new owner is totally fine with it. The rest in the image is just dust on top). Some people may get the font/logo reference

Honestly, after the absolute shitshow I experienced trying to build a...certain other tube preamp in a pedal, this was an absolute DREAM to build - and I've already started on a King Nothing.

 

[joelorigo]

Looks amazing! Do you like the sound?

 

[giovanni]

Really great work!

 

[Bricksnbeatles]

Awesome build. Care to detail the specific changes to the power section?

 

[drew.spriggs]

Looks amazing! Do you like the sound?

Pretty nice. Not amazingly high gain, but on that spectrum. Tone controls are surprisingly versatile too.

Awesome build. Care to detail the specific changes to the power section?

I don't have the exact values or parts on me, but I used a very low ESR filter cap, an inductor with a much higher current rating (as there's already something like 1.5A going through them), rejigged the values of the snubber for higher efficiency (iirc 33pf/4k7) and used a MOSFET with an RDs of something like 0.2v.

I also adjusted the feedback resistor to raise the output voltage slightly (went from about 260-280v), but it's a tradeoff as the higher you go, the less efficiency you get.