MARSHALL MG15 - Footswitch

[massimocsv]

hi,
I need to insert a foot switch on my marshall mg15, throught a female jack connetctor put on back panel, to switch the channel directly with the foot and not with the button on the control panel.
Is the possible to do that and how?

Massimo

[alexradium]

you can,just substitute the front switch with a dpdt relay and command it via an external footswitch pedal,you need to derive a 12V line from the power supply.

[massimocsv]

thanks for responding quickly.
sorry, could you draw the eletrical schematic how to connect it, I'm not very familiar with that, you can also explain me better about the 12V to derive from the power supply?

[massimocsv]

no one else could help me?

[nevetslab]

Channel Switching via foot switch on MG-15

no one else could help me?

Welcome to the Forum!

We don't know what your skill level is on doing modifications to electronic gear. Usually a mod like this involves punching or drilling a hole in the rear panel for the Footswitch jack, leaving everything else as is. And, you'd be replacing the front panel DPDT push-button switch's existing function. If your desire is to have both the front panel switch and the foot switch (to take over/defeat the front panel switch), that's not so simple. Making it Foot Pedal activated only is easier, but still you're adding some parts inside that don't have a place to mount, so it normally requires a tiny circuit board or perf board to mount the DPDT relay, and some parts to make it work.

I did some digging on the internet, and found the schematic, which shows the two sections of the FP switch, labeled SW1A/SW1B. Those contact points would be the DPDT Relay switch contacts.


Marshall MG10CDS.pdf

The circuit board images should be enlarged (sorry I didn't take the time to do that), show the switch sitting between two pots, and the foil pattern of it on the back side. You won't find a relay to fit that, so that's where the fun begins.....selecting a suitable 12VDC SPDT relay. The 12V can be derived from the +15V supply, using a resistor and a 12V zener diode to drop it down, or could really be done without the zener. A reverse-biased diode would be connected across the relay contacts, as is commonly done with all relays.

I haven't sketched any diagram to show the new circuit, which would be the foot pedal, the relay, the connections from the 15V supply, the added phone jack on the rear panel, etc.

Is this something you're capable of doing?