Big Muff troubles

[Ned Flanger]

Well I just finished my first pedal, and it does not work.  It's a little disappointing, but I guess that is the name of the game.  It seems like the effect is working but for some reason I can't get a signal from the guitar.  It sounds fine when the the bypass is on and you can hear a hum.  You can also hear things change when you turn all the pots, but no signal from the guitar.  Does any have a clue what it might be?

Thanks,

[Ned Flanger]

Alright, after convincing myself not to take a sledgehammer to my pedal, I read on the debugging post.  Below is all the Transistor voltages.  Hopefully this will help.

Biff Muff Pi (Third Edition)

Output Circuit Voltage = 0
Input circuit voltage = can't tell keeps dropping

Q1
C=8.73
B=1.517
E=1.036

Q2
C=8.73
B=1.510
E=1.030

Q3
C=8.25
B=1.426
E=0.949

Q4
C=3.640
B=1.768
E=1.186

[R.G.]

"What to do when it doesn't work" has a lot more in it than "just post the transistor voltages."

[Wales]

I would try the audio probe. Follow your signal from guitar to where it goes wrong, and report those findings.

[mmaatt25]

Your voltages are way off on all transistors.

If you search there's been a couple of recent posts about big muff trouble.

Also if you look at GGG site they have listed voltages after one of their big muff builds, I would look at these and there schematic.  I suspect with the voltages you are getting you will discover the problem very quickly.

Matt

[Mark Hammer]

Verify the transistor pinouts.  I say this not because I wish to underestimate your chops.  I say it because many datsheets just have really confusing or ambiguous pinout diagrams, and because sometimes a transistor with the same part number made by a different manufacturer can have different pinouts.  I also say it because while Japanese 2SC transistors and European BC transistors are excellent subs for 2N types, very often the pinouts are different.  Finally, I say it because even though in theory there ought to be only 6 different ways of organizing the pins, somehow it seems like there are 25 or more possible pinouts sometimes!

[Ned Flanger]

I am starting to underestimate my chops.  I checked out the voltages on GGG and they are way off.  If someone wants to give a quick tutoral on checking transistor voltages, be my guest.  Again, everyone thanks for the help.  The respect for you guys being able to build your own effects is growing immensely.