> Hi there,
>
> My A106-1's cutoff frequency range seems a little limited,
> unfortunately at it's lowest point it seems to be still in the
> audible frequency range when the resonance is right up - I'd like
> to set it a little lower to make it possible to do kick drums with it etc.
>
> I've had a little look at the board, and have seen the two
> trim-pots, one marked scale, the other marked offset, but I'm a
> little hesitant of tweaking without a little guidance! Are there
> any nominal resistance value that these should be set at, or a
> usual frequency it is set to at the lowest and highest ends, or
> is it better to just go for it and see what happens
>
> The equipment I have to help me tune it with is: a fluke
> oscilloscope/frequency counter, my ears and a set of mini
> screwdrivers. Sadly, no oscilloscope.
>
> Cheers,
>
> Andrew.

The trimming potentiometers do what the inscription says: scale and offset
of the frequency control. For the A-106-1 no measuring instruments are
required with one exception: your ear. Just adjust both trimming
potentiometers so that the frequency control knob at the front panel covers
the desired frequency range (i.e. usually the audio range).

This is the factory prodecure:
Resonance control = maximum (i.e. self oscillation)
adjust P9 and P10 by turns until about 5Hz...15kHz is covered by the
frequency control knob at the front panel

Best wishes
Dieter Doepfer