Octavia with body mod sounds like analog synth when body mod is disengaged HELP!

[joelap]

Figured I'd delete the old thread since I've solved most of the initial problems.

www.joelap.com for a soundclip of the problem, its all the way at the bottom.  That analog synth-like sound happens whenever I turn off the body mod for the octavia, found at www.generalguitargadgets.com .  I followed that layout almost identical, except I added a 3PDT stomp switch, LED, and 9VDC input.  Also, I think there's a typo in the schematic where it has the - of the battery going to the sleeve, which in most schematics I've seen going to the Ring.  So I've swapped those around.  Other than that, everything is Identicle.  Any ideas what might be causing such a problem?  My multimeter hasn't arrived through the mail yet (probably will sometime this week hopefully) so for now I cant take voltage measurements.  Any experience with such a problem?  Whats odd is that the pitch of the sound changes based on the position of the intensity knob.  Odd!  Have a listen, tell me what you think if you've got any ideas.

Joe

[joelap]

bump, could really use the help.

[Higgie]

To be honest, I think that's pretty cool!

You should build another one from scratch, and if the same thing happens, get that one fixed.

Sorry I can't actually offer any good advice

Cheers,
James.

[joelap]

To be honest, I think that's pretty cool!

You should build another one from scratch, and if the same thing happens, get that one fixed.

Sorry I can't actually offer any good advice

Cheers,
James.

Ahhh... its ok.  Its just driving me nuts.  A few people have said that they think its pretty cool too.  I just have no use for that type of an effect.   

[Higgie]

I would keep it just in case, you might get an offer on it in a couple of months time

[joelap]

I would keep it just in case, you might get an offer on it in a couple of months time

To be honest, the stock sound isnt what I was expecting it to be, so I may end up selling it anyways.  But I'd like to have it resolved before selling it instead of making it seem like "hey, I screwed up but it sounds cool".  But if anyone is interested in it the way it is, I'll leave it alone.

[disantlor]

I would keep it just in case, you might get an offer on it in a couple of months time

To be honest, the stock sound isnt what I was expecting it to be, so I may end up selling it anyways.  But I'd like to have it resolved before selling it instead of making it seem like "hey, I screwed up but it sounds cool".  But if anyone is interested in it the way it is, I'll leave it alone.

well it'd be good to figure out why its doing that so that idea can be extended on in a new design.  sounds like a guitar controlled synth, although the pitch at the one part isnt exactly following the guitar, but its very close.  Have you tried shielded cable?  My DIY tube amp was making all sorts of crazy sounds (though not the pleasant type) but once I switched to shielded wire input line it instantly went away.  Doesn't really sound like the same problem but assuming the schematic is correct and you've triple checked your wiring, I'm not sure what else to try.  Have you prodded the wires around a bit with a pencil while its on to see if the noise is somehow linked to interferance or capacitance between wires.  Worth a shot at least.

[joelap]

Ok... so since I was having this problem, I figured that I would reverse the input ring and sleeve connections to the way the diagram (http://www.generalguitargadgets.com/diagrams/toctpl_body_mod.gif) has it connected.  And there was no sound when activated.  So I switched them back to the way I originally had them (the correct way) and still no sound.  No cold solder joints, and only 3 wires were swapped.  I got my multimeter in today, and now I'm not getting any voltage readings after the transformer.  Could reversing the ring/sleeve cause the transformer to fry?  Now I'm really pissed because I went from a working pedal to a busted one by following a diagram.   

[disantlor]

Ok... so since I was having this problem, I figured that I would reverse the input ring and sleeve connections to the way the diagram (http://www.generalguitargadgets.com/diagrams/toctpl_body_mod.gif) has it connected.  And there was no sound when activated.  So I switched them back to the way I originally had them (the correct way) and still no sound.  No cold solder joints, and only 3 wires were swapped.  I got my multimeter in today, and now I'm not getting any voltage readings after the transformer.  Could reversing the ring/sleeve cause the transformer to fry?  Now I'm really pissed because I went from a working pedal to a busted one by following a diagram.   

I'm no expert but it seems surprising that reversing that would destroy the pedal.  Check the diodes though, guess its possible the reverse breakdown voltage was exceeded, though it's usually pretty high (well technically low) from what I've seen.

[John Lyons]

On the input jack (stereo 3 connections) the sleeve and ring get connected together anyway. The sleeve is ground and the ring is floating until you plug in a cord which connects the battery to the circuit and gives your circuit  power. Swaping these can't have messed up anything. The only thing which can happen from doing that is that the battery will drain itself and be always on. Ground is still ground... It's got to be something else.

John

[joelap]

I'm no expert but it seems surprising that reversing that would destroy the pedal.  Check the diodes though, guess its possible the reverse breakdown voltage was exceeded, though it's usually pretty high (well technically low) from what I've seen.

I'll check the diodes today and get back to you all.

[disantlor]

I'm no expert but it seems surprising that reversing that would destroy the pedal.  Check the diodes though, guess its possible the reverse breakdown voltage was exceeded, though it's usually pretty high (well technically low) from what I've seen.

I'll check the diodes today and get back to you all.

Of course make sure you try any of the suggestions in the debugging sticky post.  If the battery is still working, then go through the circuit connection by connection and check for voltages.  Or do a continuity check through the whole circuit to make sure a connection didnt get broken somehow.