Modding Amp Footswitches

[BeZo]

I bought some heavy duty high current dual throw footswitches and some jacks to mod my footswitches. The idea is to make isolated switch circuits to switch two amps at once for stereo goodness. I started with my 5150 footswitch by drilling a hole in the side and mounting a quarter inch jack. Most of my amps can switch with just a quarter inch cable. With the Peavey footswitch, the housing is plastic so I shouldn't need to worry about ground loops. Then I just switch out the switch and wire it up to both sides and I'm good. On my aluminum body footswitch, I'm going to put rubber ferrule around the jacks to isolate them.

My question is with the LEDs. How important is the LED for the circuit? Outside of the visual cue, do I need an LED in the circuit? Is it worth adding another LED, or should I just rely on one? If I do add an LED, most circuits I've seen just put them in line and that's it. Do I need a specific LED, or are they all created equal? Anyone else ever done this?

 

[BSRIAudio]

You can use cliff or other plastic body jacks to maintain isolation rather than grommets. Much easier.

For the switches, each set of poles on a switch is an independent circuit so you can have a 3PDT switching three amps to separate jacks if you wanted which would be fine as long as the switching polarity is correct for each amp. If the switches have the LED in the switching circuit you almost always want diffused LEDs which operate at a lower current than super brights. If you use superbrights they may cause the switching to pop or not function correctly.

 

[BeZo]

You can use cliff or other plastic body jacks to maintain isolation rather than grommets. Much easier.

For the switches, each set of poles on a switch is an independent circuit so you can have a 3PDT switching three amps to separate jacks if you wanted which would be fine as long as the switching polarity is correct for each amp. If the switches have the LED in the switching circuit you almost always want diffused LEDs which operate at a lower current than super brights. If you use superbrights they may cause the switching to pop or not function correctly.

I got Switchcraft jacks because they are solid. I guess I could have went plastic.

I guess I'll have to experiment to see if there us a pop without the LED. I don't want to mess with it if doesn't have one already. Like, the 5150 footswitch has an LED already, so I'll keep that and do the other side (the mod) without. I think I recall a pop through my Mark V switching it with the footswitch for my Verellen. Interesting.

 

[BSRIAudio]

I got Switchcraft jacks because they are solid. I guess I could have went plastic.

I guess I'll have to experiment to see if there us a pop without the LED. I don't want to mess with it if doesn't have one already. Like, the 5150 footswitch has an LED already, so I'll keep that and do the other side (the mod) without. I think I recall a pop through my Mark V switching it with the footswitch for my Verellen. Interesting.

The pop is from the wrong value limiting resistor most likely.

 

[glpg80]

Be careful with LEDs wired parallel to the switch in circuit as they can cause a holding current that won’t allow the relay to unlatch when the footswitch is changed from closed to open. You’ll need to source an LED with a current that is less than the release current rated for the relay.

If you put it in series, make sure the voltage drop is accounted for in the type of voltage needed to latch and unlatch the contact.

Also don’t forget the flyback diodes on your relays to prevent transient flyback damage.

There’s pros and cons for each topology of how the LED is wired. If it helps, basic footswitches you purchase online have the built in LEDs shunt to the switch and not in series with it.