#1
A loop pedal should be the easiest thing in the world to make, it's a switch in a box connected accross a 1/4 plug.

I have an amp with a built in loop fuction. on the back it says "tip to ground - loop" and "ring to gnd reset". i didn't have a stereo plug to hand so i made a mono tip to gnd loop pedal and it works...sorted. Then i got hold of a stereo plug so connected one switch accross the shelding to tip and the other from shelding to ring, all works ok on the volt meter, almost a zero ohm short measured when the switch is pressed, with no cross connections.

Here's the prob. unlike the mono pedal i made, IT DOESN'T WORK, not even a little bit when i plug it into the amp, even just the loop (tip to gnd) part even though it does the same thing as the mono pedal the only small difference it the resistance, the mono pedal mesures between 5 - 20 ohms when pressed and this one as i said is almost zero.

Any ideas, anything at all i can try would be very very much appriciated.

Nick
#2
So in fact you're trying to build something that you can use to trigger an on-board loop function...? I can't really follow your explanation, sorry dude.
Marshall amplifiers are the truest purveyors of rock and roll known to man.

"And give a man an amplifier and a synthesizer, and he doesn't become whoever, you know. He doesn't become us."

Holy crap, check this out!
#3
Yes sorry, your right it's something to trigger a looping fuction on my Amp. It's quite hard to explain, basically the Amp want to see a short from tip to sheath to perform a loop or a short ring to sheath to reset the previous loops. I have provided that short as required but no luck, yet the mono (just tip to sheath) works.
Last edited by nickydee at Jun 8, 2010,
#4
Okay, i understand what the amp wants. Are you sure that the amp wants a short? It seems unlikely dude. Usually they like a high-impedance trigger...

So, the mono cable allows you to perform a loop, but not reset it... hmm, are you sure that all the wiring is done correctly? That's what I guess the issue to be.
Marshall amplifiers are the truest purveyors of rock and roll known to man.

"And give a man an amplifier and a synthesizer, and he doesn't become whoever, you know. He doesn't become us."

Holy crap, check this out!
#5
I can only think of one thing for you to try - perhaps your amp wants a 'momentary' switch, therefore, for test purposes you could just plug a stereo jack into the socket & with the cover off & try shorting the tip lug to ground & then the ring lug to ground briefly with a pair of pliers.

Quote by seemeel
Okay, i understand what the amp wants. Are you sure that the amp wants a short? It seems unlikely dude. Usually they like a high-impedance trigger...

utter tosh.
Last edited by HankMcSpank at Jun 8, 2010,
#7
The switches are momentary, they are on when pressed and off when released, i've tried various durations including very quick taps.

I already know that a short from tip to sheath will trigger the loop as this is how i knew the mono switch would work which it does.

It's something to do with introducing the second switch (ring to sheath) but they work independentely of eachother so all the all amp sees is the short from ring or tip to the sheath it doesn't know a second switch exists.

None of it makes sence. I'm gonna do as you guys suggest just to double check, apply a loop manually with pliers to trigger the loop unsolder it from the switch so as to use the same cable/plug and see if it works, in fact i don't need to unsolder the switch it won't interfear in it's open position.

Thanks