> dieter, what are the advantages of ac coupling i assume that making
> modules non dc compatible (mixers, vca's, a112's etc.) has its plus side
>
> thanks, stu

Sometimes there are internal voltage offsets that cannot be avoided or only
with additional efforts (e.g. the famous Moog filter circuit and all
derivates like TB-303 or diode filter, many of the CEM circuits). If ADCs or
DACs are used these are mainly unipolar (i.e. they process only positive
voltages). If an audio signal has to be processed by an ADC it's the easiest
to inject these bipolar signals via capacitors to an internal offset which
is half of the full range (or vice versa pick the audio signal from a DC
biased DAC signal with a capacitor).

Best wishes
Dieter Doepfer