Sorry I was assuming you were scoping the output of an actual DAC IC and it's signal into the opamp.
When I just didn't like the crap people were selling with nanny state 20mA opamps and multi-band nannystate limiters... I just redid the whole circuit from scratch, rather than trying to hack an other circuit. Simply because it EASIER to redo complex analogue amp stages than it is to hack or modify an existing one.
I choose opamps that were not top of the range, I choose stable, sensible, mild opamps. Audio is not at all hard for opamps, you don't need top end instrumentation amps, Just ones that didn't limit me to 20mA, but 200mA. TI's finest OPA551. To get it stable I just used the TI reference circuit. It is a rather tame opamp. I built a headphone amp with a BOM cost of about £25. Add in the PCB cost and you are talking about £50 development costs. Such that if it were to be marketed, I'd be looking at pricing it at around £400 to make any profit. (If I solved the little annoyances that don't bother me, like the 30second power up time because I was anal about VGND noise impedance... even though I still run it on batteries so it's absolutely silent with 12db gain.