Jordan Bosstone capacitor question

[Canucker]

kind of a silly question since I'm doing up a pcb tomorrow and the second I get it done I can test it myself but I'm to anxious to find out.... I'm going to build a Jordan Bosstone fuzz and I'm lacking the 50pf capacitor....from what I have I can add a couple 33's to get to 66pf or a 10 and a 33 to get to 43....is it better to go over or be under??? http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=10962&g2_serialNumber=2

[John Lyons]

It's basically there to prevent possible oscillation.
Anything close will be fine. I doubt you will hear a difference either way.
43pf should be fine.

[Canucker]

Thanks for the info and explanation! I lucked out and found a packet of 50's so I won't have to add up parts after all...but now I know what its for!!

[brett]

Hi
using the usual filter equation (1/(2.pi.R.C)), the roll-off frequency is way up over 100kHz. So that cap could be anything from 50pF up to about 500pF before audio frequencies get cut. It would be interesting to know whether it sounds 'smoother' with a cap of about 1000pF/1nF.
cheers

[Canucker]

I went and did two boards just to make sure one works out and both did (I wasn't really worried)...so I could totally do the different caps and test them against each other.... only problem is I don't have the 560K resistors...so the one I put together today has a few resistors added together to get 552. I do have a few 580 resistors...would it be worthwhile to test some of those ;-p

[CodeMonk]

Those should be fine.
Given tolerances, they probably aren't that far from 560 anyway.

[Canucker]

Yeah I was going to go through the pile of 560s and see which one was the highest! Just to be on the safe side I ended up linking three together for each spot which totalled 572....looks so sloppy that way!