[pooleman0]

No. I sent it again today.

[pooleman0]

Here is the email they just sent me:



Hi David,

Thanks for your email. I hope it's not a lack of integrity on our
part, but I will admit to an excess of trust. We were emphatically
told (by a person we trust) that his amp was from the early to mid
70s. I looked on the paper label, and didn't see any date code at
all. Where did you find the date code?

If you are in any way disappointed, I'll be glad to refund your money.

Sincerely,
David Colburn

[Stratopastor]

just catching up with this thread...

(1) nice score, early or late 70s!
(2) Maybe for the next old Fender they'll employ a bit of caveat emptor and use Greg Gagliano's work to date the amp by serial number
(3) according to the 2 different schematics I can see on the web, there is no bias trim pot. I _think_ the way to adjust the bias is to play with the value of the 27K resistor that's connected to one leg of the vib intensity pot - on this wiring diagram (page 2) it's shown on a separate circuit board on the top LH corner of the amp. Smaller value = bias voltage closer to zero (nominally -34V) = hotter running power tubes. Like I say, I'm not 100% sure, but if it were my amp I'd replace it with a 54K just to see if it cooled the tubes or not, check the vibrato effect was unaffected, and then if all seemed well I'd adjust the value till I got the bias I actually wanted.

http://www.ampwares.com/schematics/p...z34_aa1164.pdf