at 1 khz:
and at 10 khz:
If I'm interpreting this correctly, there's a bit of ultrasonic ringing going on, which ought to be easy enough to tame by putting a small capacitor parallel to feedback resistors R12 and R14. I'd also like to see what affect altering the value of those resistors will have.
Impression to date is that the amp is pretty well designed and very listenable as-is, but I can't resist seeing if I can improve it by touching just this one part of the circuit.
