The Normal channel of the AC30HW has a 220pF bright cap over a 500k pot with a divider limiting resistor of 330k.
The Normal model has a
10pF bright cap.... is that an error?
@FractalAudio
In the real amp a 830k pot (500k pot + 330k divider limiter) has a 220pF bright cap over them, then a 1M pot will need a 180pF cap to be equal in sound? If everything is linear.
Also, a 500k/830k (60%) divider which is when volume (gain) on 10 in the real AC30HW, will be equal to about 8.5 on a 1M log pot.
AC30 HW preamp for reference:
View attachment 60050
Source:
https://www.musiker-board.de/threads/ac30hw-filter-cap-mod.728250/