TomG VCF-8 problemo

[RevTor at aol.com]

All,
 I built TonG's VCF8 (dual MS20) filter PCB a while back and it's never been 
right.  But it made a ton of noise and screached wildly so I never really 
minded.  But it seems now that one of the filters has really lost its 
filtering capability and doesn't reach self oscillation anymore.  The only 
thing I did since it last worked was power it using +-12v instead of the 
usual +-15v, and I hooked up an LED to the LFO I have wired into it....   
BUT! the other side works great still....?  
Like I said, the thing was always kind of flaky and I do remember that when I 
was building it, I had pots and switches and jacks all dangling around and at 
one point something touched something else and sparked/shorted out a bit on 
the side that is now dead.
The circut is pretty simple so I am guessing that one of the 13600's is bad.. 
 Maybe it's one of the few transistors?
Anyone here with any ideas what would cause the flaky behavior and eventual 
burn out??
I'm going to change out the 13600's tomorrow if I can find some, I'll let you 
guys know what happens!!!
thanks for any insight!!
~Steve M