DIY Pedal Question

[ritch]

I'm trying to make a Sovtek Big Muff from a tonepad board/project, and I've soldered it all together. The true bypass works, as sound goes through that way, but nothing when I click the switch.

Currently it's not assembled in the case, but should it work if I just plug in all the cables without it in the enclosure, or is there some kind of grounding issue that could cause it to not work? Thought I'd ask incase that's something I should try!

It all appears to ground to the input jack socket - one from the board itself, one from the switch, one from the output socket and one from the DC socket.

Rich

[nick]

[quote name='ritch' post='578609' date='Aug 23 2009, 10:07 PM']I'm trying to make a Sovtek Big Muff from a tonepad board/project, and I've soldered it all together. The true bypass works, as sound goes through that way, but nothing when I click the switch.

Currently it's not assembled in the case, but should it work if I just plug in all the cables without it in the enclosure, or is there some kind of grounding issue that could cause it to not work? Thought I'd ask incase that's something I should try!

It all appears to ground to the input jack socket - one from the board itself, one from the switch, one from the output socket and one from the DC socket.

Rich[/quote]

Hi,

Ummm.....should all work OK outside of the box, albeit probably with some noise due to it being unshielded.

Could be any number of reasons, why it doesn't work. Off top of my head, obvious things first; are the polarized components (caps,diodes, transistors) right way round?, power getting to effect OK?, DPDT switch wired up right....etc

Whereabouts are you based?
If you're near me, I can have a look - might be able to suss it out.

[steve]

if you build yourself an audio probe, you'll be able to trace the signal through the circuit and find where the problem is. [url="http://"http://www.diystompboxes.com/pedals/debug.html"]This site[/url] explains it

Edited August 24, 2009 by steve

[Mr. Foxen]

[quote name='steve' post='578721' date='Aug 24 2009, 01:42 AM']if you build yourself an audio probe, you'll be able to trace the signal through the circuit and find where the problem is. [url="http://"http://www.diystompboxes.com/pedals/debug.html"]This site[/url] explains it[/quote]

[url="http://www.diystompboxes.com/pedals/debug.html"]Corrected link.[/url]

[ritch]

[quote name='Mr. Foxen' post='578775' date='Aug 24 2009, 09:03 AM'][url="http://www.diystompboxes.com/pedals/debug.html"]Corrected link.[/url][/quote]


That's amazing! Thanks for sharing.

I haven't made one yet, but it looks like such a useful thing, I'm surprised no on has made one commerically! Or have they?

[Al Heeley]

So simple for people who are likely to have soldering irons and capacitors handy, probably means no demand for them commercially!
Fisrt check is all comps in right place. This is not a prob with this circuit as its pretty simple.
Second, as Nick says, ensure polarised caps are correctly aligned and transistor legs are correct.
Third, I would just recheck for any dry solder joints, have a look under a magnifying lens if any solder joints look a little weak or dry, just reheat for a sec with the iron to get the solder flowing again.
Fourth, use multimeter to trace current flow from battery through circuit. Remember to put a jackplug in the input to complete the circuit first!
I checked all the copper track traces with a multimeter before sending so the pcb integrity should be fine.
Fifth, use the audio probe technique to trace signal path. Most times, initial problem is resolved by finding a dry solder joint or maybe a solder blob spilling onto an adjacent track.
Did u use a socket for your transistors, as many are very susceptible to heat?
Good luck and hope you get it working.

Edited August 25, 2009 by Al Heeley

[ritch]

Hi Al,

Thanks for the suggestions. This problem is with a Green Big Muff clone I was also making. I started it years ago, and picked it up again recently, mainly just as practice while I was waiting for all the bits to arrive for my Reverb.

The board's a little more complicated than the reverb, but I think I've found the area the sound stops going through the board, using the probe method. I'll keep trying though.

Rich