FAQ: How do you turn them @#$% Virtual Knobs?

[RoadRanger]

It's completely non-obvious but knobs in iDevice apps aren't "turned", what you do is put your finger on the knob and slide your finger up and down like a fader . You can also double tap it to reset it to zero (usually). Once you've tapped a knob you can fine tune it by tapping on the little numerical window top-center and use the keyboard to set it to your precise OCD-driven setting .

[Trshot]

RR, I'll add that after you place your finger on the knob and not breaking the connection with the iPad surface you can move anywhere on screen to make adjustments. Allowing you to better see the knob position without hovering over it......

[musicman7722]

Hmm will check that all out.  Many thanks in advance.