Footswitching a Dynacomp Board into a Dual 50 Marshall

[David Root]

Researched but not coming up with a relay circuit. This would be sort of like switching an FET board in a single jack input to a Dumble first stage, only using the Dynacomp board instead, for a change.

I used an original Dynacomp '77 board, which fits nicely in a CE chassis where the FET board would normally be. Board is almost entirely populated now with nice NOS mid '70s parts, see pic.

I have a relay hand sketch I did years ago that just turned up again, see pic, but I'm not sure if this is something I copied or dreamed up myself. Somehow I think it needs something to "pop-proof" it, maybe a true bypass arrangement?

Comments appreciated....

[tictac]

Consider moving the 1M grid resistor to the junction with the 22k to keep a constant load on the grid....

And a cap/diode network across the coil of the relay....

A large value resistor across the relay terminals, like 10M or so prevents popping issues as well....

TT

[David Root]

Thanx, I'll try a 10M across it. And move the 1M resistor too.

I use Colossal's relay boards so the coil housekeeping is taken care of.

[David Root]

UPDATE: I found what I was looking for in one of my older files. 100W 2nd Gen Hybrid, by Jason Borders. Also a thread by Taylor Cox on a 50W version.

This layout has the relay arrg't for FSWing the FET board. It's the relay right above the FET board.

Now I'm set. Thank you Jason!