Double Flush Buzzing

[insomniac2295]

Just boxed up my Double Flush. Upon plugging it in, I find that it buzzes/hums very loudly. The LED and bypass work just fine, I just can't get it to produce any guitar sound-only a very loud buzz. I've checked and rechecked my wiring/soldering. Nothing seems to be incorrect. The buzz stops if I connect the rings of the in & out jacks, but still no guitar signal. Any ideas?

[gtr2]

I'm not sure I understand.  Do you have a guitar signal when the effect is bypassed?  Do you have pics, that could help.  Sounds like a grounding issue.  One thing that can help in future builds is to make a testing rig so you can eliminate the step of wiring up jacks etc... only to find out the circuit isn't working.

Like this:

http://www.madbeanpedals.com/forum/index.php?topic=784.0

or this

http://www.madbeanpedals.com/forum/index.php?topic=1140.0

Josh

[insomniac2295]

There is a guitar signal when the effect is bypassed. Only buzzing when on.

Not trying to be cocky or anything, but I just finished up a 5 loop bypass strip and feel pretty confident about my jack/switch wiring capabilities. I think the problem lies in the board.

When I was putting in the IC sockets, I accidentally put one in backwards. In an attempt to remove it, I accidentally scratched the surface of the PCB, making a slight connection between an IC pin. Here's a pic. The spot in question is a little left of center in the picture.

[gtr2]

Scratching the board itself isn't a problem unless you actually cut the trace.  Have you tried the circuit outside of the enclosure?  Sometimes there may be an unseen short when placing everything in the enclosure.  Some of the leads sticking out on the underside of the board should be trimmed closer to flush as they could pierce through your electrical tape on the pots as well.

Wiring a bypass loop is different than pedal builds.  There are a lot more variables.  The testing rig isn't about being cocky or not.  You need to rock it before you box it.  That way you'll know the circuit is working before you go to the trouble of wiring it up.

I still think your grounding something somewhere.  More pics would help.

[insomniac2295]

The pedal has been tested outside of the box and still no dice.
I understand that wiring switchers is different than wiring effects. I was only saying that I have a lot of recent experience with off-board wiring. I'll try to get some more pics up.

[insomniac2295]

[bigmufffuzzwizz]

When testing out of the box your gonna have to connect the ground to the output sleeve. Normally it's grounded by touching the enclosure. I'd start there, then test the dc power jack and make sure you wired it correctly. Make sure your getting 9 volts to the board. I've found it does matter what positive lug on the battery jack you solder it to. With the ground lug facing up towards you, you'd solder 9V to the outside + lug and the battery to the lower lug in the middle. That might not be the problem but it's hard to tell since there's no close up of that jack.

[gtr2]

Based on your pictures the wiring looks correct.  If your testing out of the box though you need to ground the output jack as well.  Normally this is taken care of via the enclosure.  Without doing this you will not get your guitar signal.

If it still doesn't work then you need to start troubleshooting with an audio probe.  They are easy to build in a few minutes.  Start at the beginning of the circuit and find where your loosing signal.

http://diy-fever.com/misc/audio-probe/

[gtr2]

woops you musta posted Magic while I was typing ha ha

[bigmufffuzzwizz]

woops you musta posted Magic while I was typing ha ha

Funny how that works. I was thinking that as I was typing it.

[insomniac2295]

When testing out of the box your gonna have to connect the ground to the output sleeve. Normally it's grounded by touching the enclosure. I'd start there, then test the dc power jack and make sure you wired it correctly. Make sure your getting 9 volts to the board. I've found it does matter what positive lug on the battery jack you solder it to. With the ground lug facing up towards you, you'd solder 9V to the outside + lug and the battery to the lower lug in the middle. That might not be the problem but it's hard to tell since there's no close up of that jack.

Ha! That's funny because I took a picture of the battery jack, but then deleted it, because I thought I wouldn't need it...

Based on your description, I've got the battery hooked up correctly. When I get some time, I'll hook it up to a meter and see what I get. Until then, thanks everyone for the responses!

[insomniac2295]

Update: tried a bunch of different things including changing which terminal on the DC jack the 9V gets attached to, changing up some solder joints on both board and switch. I also tried using my audio probe on it and got no sound, whatsoever. Weird.

I still get sound when the effect is bypassed, but nothing when it's on, not even with an audio probe at the beginning of the circuit!

[insomniac2295]

I'm beginning to think that there's something wrong with the switch. Possible problem?

[insomniac2295]

you know, I did use 2-3 5% tolerance resistors. could this be the problem?

[nzCdog]

you know, I did use 2-3 5% tolerance resistors. could this be the problem?

Definately not... but you'll figure it out just be methodical.  For me its almost always been a wiring error, but dud components can be a stumbling block too.

I'm beginning to think that there's something wrong with the switch. Possible problem?

Do you have a Meter? I had a dead lug on a 3PDT once and that was the problem.
Desolder the 3PDT switch and check the lugs using the continuity function...   With the lugs flat you have the equivalent of 3 'SPDT' switches, stuck side by side.

1  2  3
_  _  _
_  _  _
_  _  _

Test for continuity of each vertical row... between the middle lug and the top, then middle and the bottom... it should alternate when the switch is thrown.  A dead lug should be easy to spot, and there should definitely be no continuity between different vertical rows at all.  Hope this helps