i own my Herbert for almost 2 centuries now and i can't believe i never tried this.
Seen Ola's VH4 Metal clip and saw the "odd" setting of Deep and Presence at 0! I gave it a try.
Since the Diezel recommendation is to start of with everything at noon, i think i never swept away with the Deep knob too far from noon, let alone 2 knobs
(well that's not really true).
Well i dropped it down to 3 before, but if you leave the presence around noon, it really get's thin and brittle. I do alot of Bass/Deep exchange and Treble/Presence exchange, but never did the simultaneuos Deep and Presence change.
if you turn them down the same amount, you get similiar brightness and cut, but a different response from the Amp.
I think everything that bothers me with my Diezels from time to time (say 1 out of 10 sessions) can be removed this way.
That stuffy fatness i can't stand for low Gain can be dialed out, but in a differnt way than reducing Bass/Deep and/or increasing Treble/Presence i did normally.
If you sometimes think you Diezel sounds too fat/stuffy/muddy and just get's harsh/thin if you increase treble/presence or lower bass/Deep you should really try this.
It behaves more like a tradtional amp this way i think.