Rockman A12-50 anyone?

[drewl]

So, this is a poorly built combo amp from the people that brought you the other Rockman gear.

Schematics are supposedly nonexistent, so did anyone ever repair one by any chance?

A couple TL074's, 4053's, a TL072 and a couple FET's, so it shouldn't be too hard to figure out.

Power amp is okay, preamp controls sort of work, it switches channels, but no real gain, tone or volume control .

Uses a single +15v supply for the preamp which is odd, but only a 7815 regulator, no negative v reg.

Thanks.

[dmeek]

Someone started to trace it here: https://groupdiy.com/threads/rockman...tar-amp.63349/

Can you post photos of the circuit board, both sides?

[drewl]

Yeah, I saw that, thanks.

Waiting for the go ahead after repair quote, thought I'd try and find any info I could first

[g1]

It's supposed to use the same circuit as the Ultimatum pedal, so the schematic on pg.6 of this pdf might be of use:
http://endprod.com/filez/Ultimatum_T...Schematics.pdf

and someone's redraw of that here: https://www.freestompboxes.org/downl...3387&mode=view

[drewl]

Thanks again!

[drewl]

In case anyone else has one of these amps:

Found a site by a guy who works on Rockman stuff for members of Boston and Boston tribute bands who had a little description of the A12

Rockman Refurbs & Repairs of Massachusetts

The FX loop is after the preamp but BEFORE the master volumes, so the preamp 6 pin header is:

1- Footswitch from rear panel
2- FX return
3- FX send
4- V+
5- gnd
6- out to power amp.

Replaced bad 4053 and fixed a couple loose pot housings and bad pc board connections and preamp looks fine so far.

[g1]

a guy who works on Rockman stuff for members of Boston

Tom can't fix his own stuff? That makes me feel better.