Guide Me... Amp Footswitch Builds - Trace Elliot & Fender

[bongoben]

Alright, I totally screwed up my last build (a Tap Tempo Trem) but DanDubbleEwe has come to the rescue to resuscitate it for me. I'm not a complete soldering moron, I just probably should have started with something a little simpler. I want to build a couple footswitches for my two amps. I have a Trace Elliot Super Tramp (SS, not Tube), and a Fender Acoustisonic 30. The TE has a "Channel/Boost", "Reverb", & "Chorus" line and the Fender has a "Footswitch" line to turn on/off the onboard effects. So how are these builds? In my mind I would think it's as simple as a latching switch wired to a TRS jack, but I'm assuming there's a bit more to it than that. Can anyone lead me on my journey to build my first successful pedal?

Thanks...

[mathias]

Check the manual for each amp, it should tell you whether mono or stero jack, and whether latching or momentary (in which case, normally-on or normally-off?)

[eatyourguitar]

you will know if is a stereo jack because there are two footswitches on one cable. just look at the original footswitch for that amp. on a stereo cable, you can bet that ground will almost always be common to the two switches. then its just a matter of figuring out if it is latching or momentary. if it is latching, you just use a latching footswitch. if it is momentary, you need to figure out if it is normally open or normally closed. normally open is usually the case. working at a store I would buy and sell amps with no footswitch every day. the only way to test them was to insert a cable and remove it or just leave the cable inserted and short the other end with the ring on your finger. even if I need some slave to hold his ring on the cable for 60 seconds while I play guitar, do what you gotta do yaknow.

[bongoben]

Alright... did some basic testing (haven't been able to find anything online regarding what types of switches or schematics for their footswitches). All of my testing included your "plug a cord in and complete the circuit with my ring" method. Here's what I found:

Trace Elliot
Chorus - the effect turns on when the cord is plugged in and turns off when I touch my ring to connect sleeve and tip. (Latching switch but would it be NO or NC? I want it to have the effect off when I plug it in and turn it on, along with an LED, when I step on the switch)

Reverb - exact same as the Chorus listed above

Channel/Boost - before I plug in the cord the amp has always been on Channel 2 with the "Boost" turned on. When I plug in the cord it switches to Channel 1 and the "Boost" stays on. When I touch my ring between the sleeve and tip it turns the "Boost" off. Please note that the "Boost" is only on Channel 2's signal. I couldn't find a TRS cord to really test this line but I'm assuming that this would be 2 latching switches, 1 for the Channel switch and 1 for the Boost. I would think the Channel switch would be normally open to have the amp on Channel 1 unless the switch is stepped on to close to go to Channel 2. And the Boost switch would be NC as this would keep it turned off until I step on the switch to open up the circuit to turn the boost on.

Fender
Foot Switch - The effects are off before I plug the cord in and they stay off after I plug it in. They turn on when I touch my ring to the sleeve/tip. So a latching NO switch would be my guess.


Am I correct in my thinking on this? If so, what type of switches am I looking for? I'm still new to these switches. Also, are these switches going to work fine without power unless I wanted to add LED's? What extra parts (i.e. resistors) would I need to add in an LED on each switch?

[eatyourguitar]

on a latching footswitch, you do not need to worry about NC or NO unless you are adding an LED. adding an LED can be tricky if the factory footswitch does not have an LED. you may need to use a battery. your only connecting 2 lugs of the footswitch so it will always flip-flop bewteen open and closed circuit. your amp has normal connections built into the jacks that hold the tip to the sleeve when no cable is inserted. inserting the cable leaves the circuit open, shorting it with your ring closes the circuit again.