Help! GGG Tube Screamer buzzes on bypass!

[xpaladin1313]

I built a tube screamer from the General Guitar Gadgets site, and it works quite well.  The problem, though, is when you turn off the effect (true bypass mode, I guess).  The guitar still runs through clean, but there's a persistant buzzing noise that I can't seem to get rid of.  I opened up the box and started looking for loose connections or crossed wires... but I can't seem to find any.  I could be wrong, though.... it's a bit of a mess in there.

I imagine the most likely place for a problem is in the switch.  I've been looking at the schematic and the parts layout... specifically at the switch, and I'm not sure they make sense to me.

http://www.generalguitargadgets.com/diagrams/ts_lo_808.gif
http://www.generalguitargadgets.com/diagrams/ts-808_sc.gif

In reference to the first link there (the parts layout), why are the top-left and top-center lugs of the switch soldered together?  All it does is ground the start of the effect, right?  Could that be causing the buzz on bypass-mode?

I could be way off though.  Does anyone have any insight into this, or perhaps solved this problem before?  What should I check?  Do I need to provide any more info?  Thanks.

[jsleep]

No, it doesn't make sense.  The layout is correct.  I'll fix the schematic.

JD

[jsleep]

Fixed schematic is now posted


http://www.generalguitargadgets.com/index.php?option=content&task=view&id=90&Itemid=118

http://www.generalguitargadgets.com/

JD

[didier]

many times buzzing is caused by wrong earthing...

i would check if the output jack has its ground pin connected to the circuit ground...

it shouldnt hurt to just connect the grounds from the input and output jack directly.

did you wire it as shown on GGG?

[xpaladin1313]

How silly of me.    I actually wired the output jack backwards...   It works now!

Thanks didier.