Limiting bandwith of PRR Vari-Mu's op amp? (solved)

[living sounds]

I've got a problem with my Vari-Mu. My converter (Lynx Aurora) puts out a lot of high frequency (above audio band) noise at higher sample rates. At 176 khz this leads to the Vari-Mu producing intolerable levels of noise within the audio band. This happens with a 5532 and a lot more with an LM6172 (which sounds much better there, BTW). I've added local power decoupling caps (100nf), but this doesn't solve the problem. I guess I'll have to limit the bandwith of the op amp so it doesn't get excessive levels above 35 khz or so. How would I best go about that? Thanks!

 

[living sounds]

Worked it out (or rather, the internet did). Cap across the feedback resistor did the trick!

 

[jackies]

Cool, what size cap, like 20p?
DAC out of band noise is something I was thinking about lately. I was gonna try inductors and such, to see what would be the most effective way to eliminate it...
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[living sounds]

I used 1.5 nf caps. This translates to a roll off frequency of ca. 48 khz, which seems like a good compromise. Definitely cured the problem. The compressor still is a little noisy, but this seems to be an issue of the tube side.