Amp switching relay

GreenCustom24 · Post by **GreenCustom24** » Sun Jun 24, 2018 5:18 pm

Hey! So I'm considering running 2 different amps together in stereo. Both are 2 channels with single button footswitches, but I know I can't just use a Y cable to connect them. I use the footswitch output on my TC G System to switch channels currently and I've looked into it and everyone says that a relay box needs to be added to operate both amps at once, but doesn't say where to get one or anything. I've looked a lot and can't seem to find any readily available.

Anyone know of anywhere I can get one or someone (even from the forums here) who might be able to custom build one for me at a reasonable price?

Fakir Mustache · Post by **Fakir Mustache** » Sun Jun 24, 2018 5:38 pm

So you want it to switch channels at the same time on both amps? I'm thinking a y cable will work, it's a simple on-off switch, in parallel it should be the same if the footswitches are the same on both amps.

The only problem is that the clean and dirty channels could be reversed on the footswitch functions. In any case, this is something that can very easily be built.

GreenCustom24 · Post by **GreenCustom24** » Mon Jun 25, 2018 2:56 am

Yeah. That's exactly what I wanna do. I can try the Y cable and see. Just waiting on the second amp to come in. Damn shipping delays...

Fakir Mustache · Post by **Fakir Mustache** » Mon Jun 25, 2018 7:25 am

You'd have to get a mono to 2 mono y-cable. A stereo to 2 mono definitely won't work. A stereo to two stereo jacks should also work.

I assume the footswitches are just simple mono jacks.

Post by **Doog** » Mon Jun 25, 2018 9:50 am

A Y-cable seems like a bad idea, as you'd be effectively connecting the 2 amps together; don't do this.

Presuming they're just basic mono cable footswitches, you could easily make a single footswitch with 2 jacks, an enclosure and a DPDT footswitch switch.

All these basic amp footswitches do is connect/disconnect the ground and the hot parts of the lead, but it's worth checking that existing footswitches don't have any resistors in there too (aside from any resistors connected to a LED or something).

So if it's straight-up basic, you can keep both 'footswitch' circuits isolated in a DPDT footswitch like so:

The two wires on AMP1 side go to a mono jack (doesn't matter which way you wire 'em), the other 2 wires for AMP2 go to another jack.

If one of your amps is switching to the wrong channel (so you've got DIRTY on one and CLEAN on the other), just move one of the connections from the bottom terminals (5 or 6 in that diagram) to the top (1 or 2).

Bacchus · Post by **Bacchus** » Mon Jun 25, 2018 9:57 am

Doog wrote: If one of your amps is switching to the wrong channel (so you've got DIRTY on one and CLEAN on the other), just move one of the connections from the bottom terminals (5 or 6 in that diagram) to the top (1 or 2).

In this scenario, couldn't you just flick the switch on one of the amp itself? All the footswitch is doing is flicking those switches anyway, or am I missing something.

Post by **Doog** » Mon Jun 25, 2018 10:04 am

Bacchus wrote:
Doog wrote: If one of your amps is switching to the wrong channel (so you've got DIRTY on one and CLEAN on the other), just move one of the connections from the bottom terminals (5 or 6 in that diagram) to the top (1 or 2).
In this scenario, couldn't you just flick the switch on one of the amp itself? All the footswitch is doing is flicking those switches anyway, or am I missing something.

Hmm, I've never had an amp that worked like that.. I think the amp controls generally comes before the footswitch circuit in series.

Fakir Mustache · Post by **Fakir Mustache** » Mon Jun 25, 2018 10:37 am

Bacchus wrote:
Doog wrote: If one of your amps is switching to the wrong channel (so you've got DIRTY on one and CLEAN on the other), just move one of the connections from the bottom terminals (5 or 6 in that diagram) to the top (1 or 2).
In this scenario, couldn't you just flick the switch on one of the amp itself? All the footswitch is doing is flicking those switches anyway, or am I missing something.

That could be some kind of relay in the amp, it might also need a momentary switch. I don't think this is very common.

NickS · Post by **NickS** » Wed Jun 27, 2018 3:22 pm

I'm guessing OP wants to use the output from his TC G-System so he can just select his patch on the G-System and it will automatically switch channel on both amps along with engaging whatever effect. (The Behringer FCB1010 MIDI pedal has two relay outs you can program for each preset).

NickS · Post by **NickS** » Wed Jun 27, 2018 3:45 pm

http://bit.ly/2KmFZTF would run off a 9v (pedal) PSU. Plastic project box, jack sockets, stripboard, power socket and you're there.

GreenCustom24 · Post by **GreenCustom24** » Wed Jun 27, 2018 10:46 pm

NickS wrote:I'm guessing OP wants to use the output from his TC G-System so he can just select his patch on the G-System and it will automatically switch channel on both amps along with engaging whatever effect. (The Behringer FCB1010 MIDI pedal has two relay outs you can program for each preset).

Indeed! That's exactly what I want to do. The G System has 2 footswitch outputs but they unfortunately strictly operate independently...

I'll check out the link you posted. Thanks!

I'm atrocious at wiring so I might have to commission someone... Ha