need help restoring vintage big muff

[chuckocaster]

hi, this is my first post.

a friend of mine a while back gave me a vintage big muff because it did not work. he said it was mine to keep and hopefully i could fix it to use. this past month i've been building some pedals and circuits off jack orman's site and felt i might be ready to dive into this project.

the problem i'm having though is that i can't seem to find a good pic of the board layout. from the research i've done it appears that i have somewhat of an oddity. what i have is a 3003 board, but it is in the second enclosure. on the one picture i found the board is designated 3003, but the layout of the components is different, also none of the inputs, ground, etc are labeled on my board like they are on the one i looked at.

i have been able to get the box to pass signal, and even turn on, somewhat. but the effect is VERY quiet. i was hoping someone here might have some idea of how to fix this. it appears that all the components are original except for two of the pots (vol and fuzz), and a dc jack. someone before me had tried to work on it, the guy who gave it to my friend. but from somewhat cross referencing the layout picture i have it seems like things are somewhat in order. here is a pic of the board as it is now.



any help would be greatly appreciated. thanks guys!

[aron]

The audio probe will fix that guy up really fast.

See my Debugging page link above.

[Sir H C]

http://www.big-muff.net/big_muff.php

has a lot of good pictures of many a big muff.

In general there is a logic to the layout, you know that you need:

+ battery
- battery
in
out
and maybe the switch (tone bypass or power)

In the schematic you can see each has a unique set of things attached to it.  So, find the resistor for the input, make sure that is right.  Keep going that way.

http://www.montagar.com/~patj/bigmufpi.gif

seems to be the right schematic to use.