In the area near those power supplies (bottom right) no modules should be assembled that are sensitive to transformer hum.
Doepfer recommends to assemble only control voltage modules in this area (e.g. LFO, ADSR, trigger delay, clock divider/sequencer, sequencer, slew limiter, MIDI interfaces and so on)
,but no audio modules (VCO, VCF, VCA, VCP, frequency shifter, ring modulator, spring reverb and so on)
Also don't put the A-178 Theremin modules near the power supply.
|Doepfer Power Supply I ( PSU I )|
For new A-100G3/G6 cases (with original PSU II) this does not apply.
More info at http://www.doepfer.de/a100p_e.htm#A100P6