[sdiy] Buchla 266 Integrator question

[Fahl, Romeo]

I'm trying to get the integrator (slewer) from the Buchla 266 (see
http://www.takeonetech.de/buchi/magnus/synths/companies/buchla/Buchla_2660_4
_200.jpg) working.   For the most part it works, but it oscillates at a very
high frequency at the output.  Looking at the schematic, I can't for the
life of me figure out why.  I replaced the 3080 with another.... no
change....    Just for kicks, replaced it with a TL071 (leaving pin 5 out of
the socket) and the oscillation stopped...  Could it be that the expo
converter is misbehaving?  Nothing like a bad circuit to bring on a case of
tourette's...

I also noticed that as drawn, the circuit could not handle a VCO's CV input.
I had to add a 1K resistor at the output before it would drive anything
other than a scope probe.

Any thoughts?  

Romeo (wishing I could swear in Russian)