Hi all!  Great help on this site for me so far.  I still have a couple of questions though.  Firstly, looking at this wiring diagram of a tubescreamer
http://www.generalguitargadgets.com/v2/diagrams/ts_lo_808.gif
I only see about 3 caps that have polarity.  I don't understand.  Are they all supposed to be non-polar?  If not, how can I distinguish between the orientation of the caps other than c7,c11, and c12 (ie, what orientation is cap c3 supposed to have etc.).  Secondly, how do I distinguish the polarity on film caps?  I have tantalums that have a stripe down the positive side, but the polyester film caps I have don't show which is which, so how do I tell?  Finally, capacitor C4 is 51pf, which is really hard to find (or at least I've been having trouble finding it).  Would replacing it with a close value, 56pf do the job without altering the sound?
Thanks again for all the help.  I feel so new to all this...
:roll:

Hi there,

If there's no + or - designation for a cap, it doesn't matter which way it's oriented.  If you can hear the difference between a 56p cap and a 51p, your ears are way better than most!  That's definitely "close enough for rock 'n' roll"!

Good luck with your build!

Jim

in most cases, only electrolytics and tantalums have polarity.  Ceramics, polys, green caps etc. are non-polarised.

So all the caps on that diagram that are not marked with a polarity should NOT be electros or tantalums.