Amp footswitch

[Carpediem]

Hi, I'm a newbie here, from Macedonia. I'm just starting to dabble into electronics, and I'm a guitar player. So, I decided to build a footswitch for my amp. It's got two channels: clean and distorted. Now, I'm using my friend's FS at the moment, and that one has 2 switches (I guess stomp switches is the technical term.) One of 'em switches between channels, and the other turns on/off the boost. I opened it to see what was inside, since I wanted to find out how it worked.
What I saw was: of course - normal, 1/4'' stereo jack, and a 3 conductor wire on the outside. In the jack, I saw, in my case, the blue (insulation, clearly) wire soldered on the smaller piece of metal, the pink one on the bigger one and the shield, normally on the lowest surface (I know it's a poor terminology as it can be, but I'm really just starting.) Now, in the box: the pink one led to the sticking pin of the switch (channel), the blue one exactly the same but to the opposite switch (boost), and the shield was separated in two, each part connected the middle sticking pins of the switches. And that's it. Can somebody please explain this concept to me? I'd be REALLY grateful. I definitely don't wanna buy a 40$ footswitch.
Thanks a lot. I'm using a Peavey ValveKing 112, btw.

[Carpediem]

Anybody? I know that it's totally beginning stuff, but.. hey, you've got to start somewhere.

[bnwitt]

It would help if you told us which amp you have.

Basically the stereo plug on your footswitch has three contacts. The tip, the ring, and the sleeve. The sleeve is typically connected to ground in the chassis but not always. It depends on the amps switching circuit. The tip is one function and the ring is the other function.

[txstrat]

It would help if you told us which amp you have.

Basically the stereo plug on your footswitch has three contacts. The tip, the ring, and the sleeve. The sleeve is typically connected to ground in the chassis but not always. It depends on the amps switching circuit. The tip is one function and the ring is the other function.

...and with the switches you (probably) shunt either wire to ground (in this case where you use 2 switches) and activate (or deactivate) the specific circuit.

Sorry bnwitt, don't wanna sound like a smart @ss but since Carpediem is quite new to electronics I thought I'd add that.

[Enzo]

Hi CArpe, welcome to the forum. I understand you are excited to get this running, but really, allow more than 45 minutes for someone to reply. Not everyone is online all day.


bnwitt - he did mention he has a PV Valveking 112 in his last line.

You described what you need. The FS cable has two inner conductors and a shield around them. The shield will be wired to the ground terminal in the plug - the "sleeve." In the FS box, that ground/shield will be wired to one terminal of both switches. The two insulated wires will be connected to the remaining terminal of each switch, then up in hte plug, one wire to the plug "tip" contact, and the other to the plug "ring" contact. Just like they sound, the tip on the plug is the pointy end, and the ring is that extra band around the shaft of the plug - the band that makes it a "stereo" plug.

it operates by each switch grounding the appropriate wire - that is how the circuit works in the amp.

I will leave it to you to determine which switch does what?

[bnwitt]

bnwitt - he did mention he has a PV Valveking 112 in his last line.

Damn I missed that. And I pride myself on being thorough.

[Lee W]

It's even more fun, and not too overwhelming for a first project, to include LED's in your footswitch. This was the exact same first project that I did in electronics.

I had a 2 footswitch Marshall pedal, one for channel changing, one for reverb. I had a green/red LED for my clean/distorted channels, and a regular orange LED for reverb. You can buy a red/green LED with 3 wires coming out of it, so it's two LED's in the same casing.

You will need:
A project box for building the pedal
2 DPDT push button switches (search a bit online to figure out how these work)
A green/red LED and another regular brightness LED
Two resistors of correct value (look up LED info online, most run on about 2V and 20mA, you can do the V=IR calculations from there)
A 2.1mm DC in chassis mount jack for compatability with any pedal power daisy chain supply
A stereo chassis mount 1/4" jack

[Carpediem]

Guys, thanks a bunch for showing interest, I appreciate it. Now, I wanna ask: how do I know which switch terminal should be connected with both the conductors and the shield? BTW, sorry for rushing with the 2nd post. I'm guess I'm a bit too impatient.

[txstrat]

Do it like in the sketch.
You need two SPST (single pole single toggle) switches.
Which terminal doesn't matter since you just close the circuit by stepping on the switch.

[bnwitt]

By the time you buy all of the parts you could just buy a ready made generic one with LED's for $21.95 from Antique Electronics. Look under footwitches, Marshall and replacements, bottom of page. The one without LED's is $19.95

http://www.tubesandmore.com

[Carpediem]

Just one more thing: Txstrat mentioned SPST switches, but Lee W - DPDT ones?

[Enzo]

I can't speak for Lee, but I would be assuming he used the extra switch contacts for running the LEDs. SPST is sufficient for the basic footswitch function.

[Lee W]

I can't speak for Lee, but I would be assuming he used the extra switch contacts for running the LEDs. SPST is sufficient for the basic footswitch function.

That is correct Enzo, as always

For a switching only function, SPST is sufficient.

I used a DPDT switch to isolate the LED power circuit from the amp relay circuit.