The Amp Garage

I wasn't going to admit this. It's about the saddest tale you'll ever hear. I got hold of an old Concord tape recorder and it had one dozen Telefunken 12AX7 that all tested at 30%. I chucked them all in the trash. This was about 15 years ago. I still wake up in a cold sweat over it. Ouch...I saw so...

Also, check carefully the notes on the B&K. For instance, my B&K says a 30% test is full factory spec on a 12AX7. Some of your tubes may actually be ok, they just don't test in the green. Ditto that, I would probably hang on to any 12AX7 that passes shorts & emissions on a B&K tester especially the...

gearhead wrote: I would be interested to know what s "Special Process" was to ensure little need of bias adjustment for years to come!

just guessing but didn't Ken use "graded" groove tubes? if so you could pick the same number and drop them in.



David

utervo, Just in case you haven't seen it there's some good info for a Champ build at Angela's ,well actually a 5F2 Princeton but some good layout, tips etc. I did mine with mostly all used parts,transformers and 6" Oxford from a console (10 or 12 would be bettter) cc resistors, caps are Atoms and th...

Those should work just fine, I forgot that my Makita hand drill is 1/2" so no problems



thanks again

db

Brian,

Thanks for the pictures, sharpie marker is a good idea. Are those 1/2" shanks on those and do you use a press or hand drill?

David

Brian,

What brand and p/n of step drill do you use? Also in the market...

thanks

David

Sorry to go off topic but I must say Alex nice amp

David

jelle wrote:David,

Thanks for the response! Please let us know.

Jelle,
Sorry I haven't been able to find those notes but the big base jogs something in my addlepated mind

David

Aren't these amps designed around the Siemens EL-34? Jelle, I'm not sure if it was designed around that specific brand or he selected by trial and error. I had ordered and Express in the mid 90's and Ken said he liked the Siemens and older brown base Mullards the best in that amp, damn if I can rem...

Sweet sounding



David