DIY Footswitch

[blah]

Hi guys!

Greetings from Slovenia (Europe)! My first post on this forum!   

I was building a footswitch for my tube amp Laboga Studio Reverb. It just have two channels, so I need just 1-way footswitch with LED. But now I have one problem. The LED light is turned on when switching to clean channel. What I did wrong? And also, why are both lights turned on when footswitch is on (on the clean channel)? I also put a video on YT, so you can see the problem. I work after these schematics:



I also put a video on YT, so you can see the problem.

Thank you very much for helping in advance!

And I also put a demo video of Laboga, if anybody is interested for it

[Granny Gremlin]

The LED on the footswitch is always on because the switch never breaks it's circuit; always connected.  When you engage the switch all it does is add a parallel path (short) around the LED which is always on.   I suspect the amp is confused because the circuit is always complete, but with 2 different impedances and therefore 2 different voltages vs on or off (I am not sure if it is a good idea to have an LED in the circuit like this - not familiar with the amp).

Try it without the LED and it should work.  If that's fine then you can try putting the LED back, but put it in front of the switch input (vs either output, or bypassing it altogether as you currently have).  Like I said, having the LED in there might not work depending on the amp circuit.  If so drop the LED permanently or use a DPDT - first pole wired like you have but without the LED path, and the second pole completeing a battery-R-LED circuit.

[greaser_au]

Hi Marko,

Are you able to provide a schematic of the amplifier  (or a link)?  I wasn't able to find one easily.  Analysis of switching is always entertaining

david

[blah]

First, thank you both for respond

Granny Gremlin: I tried without the LED and it works perfectly, without the both lights. But you must know that, channel is switched, just the both LED lit. So it is just a cosmetics problem... Yes and there are also two voltages, when LED is on there is around 13V and when is off is 22,6V.

greaser_au: I will try to find some out. I'll also write to Laboga, maybe they'll send me.

[slacker]

Why did you use that circuit? Do you know if it is supposed to work with your amp?

According to the people selling that pedal it's for certain Marshall amps it might not work with other amps.
http://www.amprepairparts.com/marshallfootswitch.htm

[blah]

I just take the first circuit which I found on google. And if you write in google "marshall footswitch schematics" you get that picture

Maybe anybody have some other circuit? Beacuse it boders me, that LED is on when I'm on clean channel and it's turn off when i'm on drive channel.

[slacker]

It looks like the actual Labogo footswitch doesn't have a LED http://laboga.pl/sklep/en_GB/p/Footswitch-Channel/294 so it might not be possible to do what you want.

You could add a LED by using a DPDT switch using the other half to power the LED using a battery like shown in the first picture here https://lesuedoids.wordpress.com/category/modding/

[blah]

Yes, I know that with battery... I think I'll must do with batt. Just one question, when I'll have cable in jack of footswtich, will it expend the battery?

[slacker]

The battery will only be drained when the LED is on.

[blah]

Aaaa great Thanks!

What about LED mod FS on peavey classic? Does anybody have cool circuit? Beacuse there I have problem that, LED is on when you turn off reverb and the other LED is on when you have on clean channel. I use this circuit: http://i.imgur.com/RGoFO.png