The worst area of rolloff is typically around the middle of the control rangeThat will be for linear pots, with logarithmic pots it’s more like 1-2 o’clock as we have here with a 100kohm "A" taper pot. If this amp were to used as a poweramp, it would be better for the volume control to be removed and a 100kohm resistor in it’s place to ground, and the gain dropped by 50% by a tech, Then there will be no series resistance causing any HF filtering. And a + could very well be a tighter bass with lower gain/higher feedback, which was it’s only area of question in reviews.
"beautiful sound with minimal distortion, but not too well-controlled bass"
Cheers George