Cap issues for Big Muff

[shawsofhell]

I'm building a BM using the pcb off the tonepad site and was just looking at the parts list and saw tat it needs 500pf caps. The only caps I can get that are close are a 470 and a 560. I was thinking i could just wire a 470 with a 33 in parallel but realised there probably isn't enough room on the board to do this. Any suggestions?

Also I have seen that people often change some of the caps on it to get a better tone response. Which caps should I change?

Finally do you guys use Tantalum or Electros, Greencaps or Ceramics (This question is in general to all circuits)

[Gringo]

When i built it, i changed all the marked 1uF's (the ones at the pdf with *'s) down to 0.1uF.

I'd socket the input cap, and try even smaller values, also.

Have you read the build reports at tonepad? They are not very "technical", but useful anyway.

Good Luck.

[Skreddy]

I'd use the 470pf caps, especially since that's what the original schematic actually calls for*.
(*Edit: No, not really.  I can't back that up.  It should work fine with 470pf caps though!)

As for the input and coupling caps, what I've found is that for the BMP circuit (and only this circuit), best, most 'authentic', most 'cranked-amp', and most 'mojo' are to be had with ALL CERAMIC .1uf caps.  They add to the general low-fi grit and tend to reduce high-frequency harshness.  

In general, though, most other effects tend to sound better with hi-fi caps like poly.

The only things I'd tell you to socket would be the transistors and the input and output caps.  Experiment with medium/low-gain (instead of high-gain) transistors for a creamy, non-harsh tone.  Experiment with a *slightly* smaller input cap for a less 'Muffy' tone (but then it IS supposed to be a Big Muff, isn't it???).  Experiment with a larger output cap (hey, try 10uf tantalum) for huge, open bottom end.