SOLVED Tommy Bypass Issues

[Stephenthegun]

So I am having a really frustrating issue for which I am sure there is an obvious answer I am simply too dense to see. When the pedal is engaged the thing sounds fantastic, but when it's switched into bypass mode it hardly allows any (but does allow some) sound through. I thought my switch was bad so I replaced it, but here I am again with the same problem. What am I missing?

Any help is much appreciated!

 

[jimilee]

Disengage (bypass) the pedal and use your DMM to see if there is continuity between lugs 9 and 9.

 

[Laundryroom David]

Disengage (bypass) the pedal and use your DMM to see if there is continuity between lugs 9 and 9.

3 and 9?

 

[jimilee]

3 and 9?

Sorry no, 8 and 9

 

[Laundryroom David]

Sorry no, 8 and 9

That makes way more sense than 3 and 9

 

[Stephenthegun]

Thanks so much, guys. I will check this out tonight. Your help is greatly appreciated. My wife and I just had twins, so my free time is at an all-time low, haha.

 

[Laundryroom David]

Thanks so much, guys. I will check this out tonight. Your help is greatly appreciated. My wife and I just had twins, so my free time is at an all-time low, haha.

Congrats!

 

[Stephenthegun]

So I tested continuity between 8 and 9 and there was continuity.

 

[Chuck D. Bones]

Hard to tell from the pix, but is the out jack contacting the VOLUME pot?

 

[jimilee]

So I tested continuity between 8 and 9 and there was continuity.

Perfect. Got an audio probe?

 

[Stephenthegun]

Hard to tell from the pix, but is the out jack contacting the VOLUME pot?

Thanks for having a look, Chuck. I had a look and the output jack is not touching the volume pot.

Perfect. Got an audio probe?

I do not have an audio probe, but it looks like it should be easy enough to make one up. Since the pedal seems to work fine when engaged this should make the probing pretty limited I would assume. Still trying to figure out in my head what could be the problem if it isn't the switch?

 

[jimilee]

Thanks for having a look, Chuck. I had a look and the output jack is not touching the volume pot.

I do not have an audio probe, but it looks like it should be easy enough to make one up. Since the pedal seems to work fine when engaged this should make the probing pretty limited I would assume. Still trying to figure out in my head what could be the problem if it isn't the switch?

Yeah, no kidding, I mean it comes in, goes across the switch and goes out.

 

[HamishR]

Is your input jack wired right? It looks like the signal is connected to the sleeve rather than the tip.

 

[MichaelW]

Is your input jack wired right? It looks like the signal is connected to the sleeve rather than the tip.

This.

Looks like the input is connected to the Ring lug and not the Tip on your stereo jack.

Edit: I take that back, it looks correctly wired.

 

[HamishR]

Does it? I can't tell.

 

[MichaelW]

Does it? I can't tell.

Yah, the lug corresponds to the contact on the opposite side. I think it's correct. Hard to see the ground nib because it's at the bottom.

 

[Stephenthegun]

Yah, the lug corresponds to the contact on the opposite side. I think it's correct. Hard to see the ground nib because it's at the bottom.

I just double-checked and yes, it is indeed hooked up correctly.

Perfect. Got an audio probe?

So, I just built an audio probe and tested out the lugs on the switch and the output jack. When the guitar is plugged in it is still very quiet in bypass mode.

 

[jimilee]

I just double-checked and yes, it is indeed hooked up correctly.

So, I just built an audio probe and tested out the lugs on the switch and the output jack. When the guitar is plugged in it is still very quiet in bypass mode.

Did you start at the input jack and trace it?

 

[Stephenthegun]

Did you start at the input jack and trace it?

Thanks for your help. No, I didn't test the input jack although I did test the input at the switch. I will test the input jack and see what it sounds like. I am confused as to what is wrong. It seems like it should be the switch, but I am getting a signal with the probe (though I am not sure how strong the signal is). I tested the guitar with other pedals so I know the cables and guitar are good. I have never used an audio probe, but I will blame my failures to figure this out on lack of sleep.

 

[jimilee]

Thanks for your help. No, I didn't test the input jack although I did test the input at the switch. I will test the input jack and see what it sounds like. I am confused as to what is wrong. It seems like it should be the switch, but I am getting a signal with the probe (though I am not sure how strong the signal is). I tested the guitar with other pedals so I know the cables and guitar are good. I have never used an audio probe, but I will blame my failures to figure this out on lack of sleep.

Yep the input works, the objective is to trace the signal from a good point to see where it stops.