no sound from effects with one specific amp?

[ezanker]

A friend called me last night with the following question:

He has a few effects (some built by me and other commercial models).  At home everything works fine.  He then goes to a neighbor's house to jam and plugs into his neighbor's fender twin only to find that there is no sound when he turns his effects on (sound comes through when the effects are bypassed).

The effects are battery powered.  He is using the same cables and guitar in both houses.  The only difference in the chain is the amp. He tried toggling the ground lift switch on the twin and plugging into different inputs on the amp.

Also, the house is pretty old so there is a chance there are problems in the wiring in the house.

Anyone have any ideas of what might be going on here?

[gght]

An obvious case of "pedal shenanigans"!! Actually I have no ideas, but will watch a REAL answer!

[John Lyons]

It's got to be a power issue. Most likely they are getting power somehow.
There isn't any reason otherwise. But with battery power...very strange.
Are the LEDs coming on? With several pedals all acting up then something
is definetly fishy.

[Paul Marossy]

Does his friend have another amp at his place besides the Fender Twin to try his setup with? Maybe it's the amp that has the problem.

[ezanker]

Thanks for the comments!
I have not seen this first hand and am taking my friend's word for what is happening.  He says the LEDs on the effects come on, but there is no sound.  I don't know if his friend has another amp available, but I'll see if he can bring one of his amps to his friend's house.

If anyone else has an idea, please feel free to chime in.
Erik

[wavley]

I say this only because I've done it.  When I was a teenager I bought a wah pedal, hooked it up with my distortion+ and a DOD Phasor, guitar signal worked fine bypassed, no effects, convinced that it was the new wah pedal causing the problems I took it back and exchanged it.  I took it home, hooked it up same thing, everything was fine bypassed, no effects.  I changed batteries in everything twice, had my friends try it on their amps, nothing.  So I started looking and realized that I had wired everything backwards, my guitar was plugged in to the output and amp in the input.

Sometimes the biggest problems have the simplest solutions.

[John Lyons]

Yes, I agree. The odds that all the pedals are broken/not working are very high.
It's got to be a simple oversight.

[ericohman]

I had the same problem with my jtm45 clone and my breadboarded rangemaster.

It worked on the Normal channel but not on the bright channel. I posted a photo on this forum of my breadboard and someone spotted that my output cap was shorted... so I guess there were a lot of dc offset on the signal, which somehow might have reacted strange in the jtm45 bright channel.
my 2 cents..

EDIT: sorry, sloppy reading of your original post. seems like it's a discussion about where several pedals doesn't work... but at least you know what you can look for in case something works on the normal channel but not on a bright channel

[dschwartz]

99% chance your friend connected the pedal inverted..
Assumming it is truebypass:
the bypass still sounds=cables OK
Light is on= power is OK
No sound when engaged= pedal is broken, or reverse connected.

there´s nothing wrong with the amp. i´m pretty sure it was connected wrong.

[Paul Marossy]

Yeah, actually I also vote for something being connected backwards. Although, if he was consistently doing that, then the amp at his own place also shouldn't work...

[ezanker]

Thanks again for the theories!  I'll check with him again. 

It just seems odd that they would work at home, but not at his friends; you would think he would get it backwards consistently.

I agree that it is probably a simple oversight, and if I can get over there soon I will hopefully see it...

Erik