BossAreaForum

This was the PCB damage under the original location of the 10W power supply resistors.
.

In case you have an interest...
.

It all came full circle. Coincidentally I atteneded a small jam session last weekend and it was the amp of the other guitarist. A Gretsch guitar, VOX wah, couple of other pedals and that. It was quite dark and jazzy but nice! I'd be interested to hear what output tubes his amp has? If the originals...

I like a lot of the features of this era amp, the series or parallel extension speaker jacks, the tube testing and bias access, the parallel channel input jacks... Agreed. With a few engineering tweaks (better resistor heat management...), and the addition of a "vibrato", it would be the perfect am...

Thank you! Yeah heartbreaking to see these old amps so badly treated/maintained.

Happy to save them when I can.

My 1989 red-knob "The Twin" resurrected. What was done.... New output tubes. New output tube sockets with new screen and grid resistors. Weak V1 (12AX7) replaced. Failed V4 (12AT7) replaced. 10W failed/failing power supply resistors moved off-board to 25W resistors mounted on a custom fabricated hea...

Solid little rig! What is the brown pedal?

Thank you!

It isn't quite finished. The reverb was sounding very thin. One of the transducers has failed mechanically and one of the two springs has detatched. Not repairable unfortunately, but easy to order a new one (about 50 Euro).

Pepe wrote: ↑

Sun Jul 05, 2026 12:50 pm

Ah, I didn't see that at first look. How very strange! GDR components in an American amp?!

Apparently it was fairly common - Google tells me this particular tube was widely used.