True-bypassing Green Muff problem

[palthegiraffe]

I have a green Sovtek Big Muff that I brought back from the dead. I fixed it successfully, and it sounds great.

Now I'm trying to true-bypass it, switching out the DPDT switch with a 3PDT switch. I have done the usual layout for this, but it doesn't seem quite right. Now, the pedal works, but the tone is more muffled, and the sustain/distortion knob acts weird: it shuts off completely when turned all the way counterclockwise, and is not as thick/distorted a sound at any setting.

Has anyone here done this operation before? What could the problem be?

[Dan N]

Of course true bypassing should not cause those probems. You need to really recheck where your switch wires are going.

My first thought was whether you remembered to cut the trace from the input jack, but even if you didn't, it should not do the things you mentioned.

[Dan N]

Here's something.

http://users.rio.com/senorris/junk/blrusbmptbp.jpg

[palthegiraffe]

If I understand correctly, the six posts on the original DPDT switch were the circuit in, circuit out, input jack, output jack, LED, and ground.

The LED, input jack, output jack, and circuit out wires were easy to figure out and put in the right places on the 3PDT switch. The circuit in and ground wires, though, didn't look like they came from the right places; one of the original six connections was to the center lug of the distortion pot. That one confused me.

I wish that I had a schematic that showed the original layout with the DPDT switch, too.

[bobbletrox]

Hey!  You won this auction: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=7266&item=3723389864&rd=1

I was watching that one  

[Dan N]

Umm, I am going to have to stare at this sucker for awhile. First thing, the pole of the original switch seem to be pin #1. Not pin #2 like in more familiar switches.

The center of the distortion pot is going to ground in bypass. You can just snip that wire when you true bypass it.

[palthegiraffe]

Hey!  You won this auction: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=7266&item=3723389864&rd=1

I was watching that one  

That's the one! The paint is so bad that I can't decide whether to give it a cool paint job, or call it a "relic" and leave it as is.

[palthegiraffe]

The center of the distortion pot is going to ground in bypass. You can just snip that wire when you true bypass it.

I was wondering about that. That may be the problem. I'll give it a try.

[palthegiraffe]

The center of the distortion pot is going to ground in bypass. You can just snip that wire when you true bypass it.

This was the answer. Thanks! It now works just fine with the 3PDT switch. Awesome.