DBA Sound Saw - Help with nuisance issues

[Morbidpale]

Looking for a little advice. I breadboarded this and like it quite a bit. So I drew the schematic out so someone could actually read it. I went ahead and fixed the pots so it was "correct". I also added power filtering and a PDR at Input.

Couple of problems:

• The Filter switch makes a popping noise when flipped. I'm not sure how to address it. I tried pull down resistors and caps to maybe isolate from DC but to no avail.
• Filter 2: The dual Filter pot makes a lot of noise when turned, to a lesser extant so does the Filter 2 Volume. Is this expected or something we can fix?
• Quite a bit of hum in general but I think its just breadboard noise. I haven't seen any comments on stripboard builds that there is a problem.

I was thinking maybe some 100r-ish sized resistors on the collectors to ground for stability. I'm not sure that matters in reverse beta. Thoughts?

Schematic came from:

Death By Audio Sound Saw

Collection of vero (stripboard) & tagboard layouts for 100s of popular guitar effects, with over 1000 verified designs. DIY your own boutique effects!

tagboardeffects.blogspot.com

Thanks All.