Aw man, I was just getting into a Ross phaser, that's on hold now cause I've been wanting a Zippy (apparently I can't have too much zippery fuzz, just finished a Pixel). Thanks so much for this, cutting the vero now!
Here is a verified layout of Basic Audio Zippy Fuzz drawn from schematic of PedalPCB Zipper
MPS6513's seems to be hard to come by but any low gain NPN Si works fine. I settled on a couple MPSA06's.
You don't happen to have a recording you could share... do you?
And looking at that schematic, am I right in thinking that 1k on the switch changes the resistance of the collector from 47k to 2ohms (1/Rt = 1/R1 + 1/R2; or 1 divided by 47,000 + 1,000 = 2.08)?
Edit: In case anyone cares, it's actually 979.16ohms. My first mistake was to not correctly use the formula I posted (it should be 1 divided by 47,0000 + 1 divided by 1,000, then divide that total by 1). My second was to use the wrong formula: since they are only two resistors in parallel the formula is R1 x R2, then R1 + R2, and divided the totals.