Doepfer

> do the filters self oscillate (as both lp and bp)? if so, you've then
> got six lfo's if the filters aren't being used.
>
> and can anyone tell me how good the tracking at 1v/oct is? i tend to
> use a lot of filters as oscillators, and i've been eyeing this module
> for a while.
>
> thanks, stu

The A-127 does not self oscillate as resonance filters usually do not have
this feature. And the CV inputs are not trimmed for 1V/oct as the main
application of the A-127 is the frequency control via the internal LFOs.
That's why we didn't turn our attention to 1V/oct scaling of the frequency
control inputs. The module is adjusted so that the internal LFO covers the
whole frequency range when the manual frequency control is in the center
position and the CV amplitude control is fully clockwise. But you could
adjust the trimming potentiometer P7 to obtain 1V/oct scaling of the CV
input.

To obtain self oscillation the module has to be modified a bit: a resistor
in the filter circuit has to be changed. I'll have  to try out which one
(probably R13, but I'm not sure).

This information is valid only for the new version of A-127 with CA3080 OTAs
(manufactured since 2001). For the old version (with CEM3382) it's mroe
difficult because there is no trimming potentiometer for the CV scale
available. In this case a resistor of the CV summing amplifier has to be
replaced by the combination of a resistor and trimming potentiometer to be
able to adjust the scale.

Best wishes
Dieter Doepfer