Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: smilan on June 23, 2022, 04:30:21 am
-
Hi,
I'm in the process of restoring a GEM Mars GR 30 amp.
I have some issues with the reverb circuit.
I can't hear any signal coming from the reverb. If I'm hitting the reverb tank I can hear it.
It's also seems like someone in the past was in there and it seems like the tank has connected backwards (the wire with the dry signal was connected to the tank's output terminal and the wire that goes to the reverb potentiometer was connected to the input terminal. Also on the wire that goes to the reverb pot there is 120V DC that might be too much?
A schematic for the reverb circuit will be very helpful.
-
A schematic for the reverb circuit will be very helpful.
Yep.
-
A schematic for the reverb circuit will be very helpful.
I'm in the process of restoring a GEM Mars GR 30 amp.I have some issues with the reverb circuit.
you could draw it as you go, refine it, repeat til it's restored to original :icon_biggrin:
-
I draw this schematic of the reverb circuit. I hope I didn't made any mistakes.
Does it make any sense?
-
> Does it make any sense?
Not to me, yet.
Here is a GR-40, similar, but seems to be missing a lot of reverb detail.
https://www.pascalchour.fr/hifi/gem_mars_gr_40.htm
-
I saw this schematic, but the reverb circuit is not shown there.
I replaced all the old electrolytics and the amp working well exepet for the reverb...
-
I redraw the schematic.
This one supposed to be she same as the reverb PCB