[ProAudio] Muncy Revisited: Pin 1 to chassis through a capacitor?

[John Chester]

On 12/2/23 8:09 PM, Bob Katz via ProAudio wrote:
> As for the “AC side” versus the “DC side” of the 0 V line inside the
> power supply, the schematic shows it to be a continuous trace from One
> side of the Board to the other so I’m not sure of the distinction if any
>   unless we’re looking at micro currents I imagine.

Current through the 0 V trace on the AC side will be capacitor charging 
current, with a fairly high peak value.  Depending on the PC board 
layout, this may create several millivolts of voltage drop across the 
trace between the 0 V terminals and the filter capacitors.  Thus, there 
may be significant noise voltage between the 0 V terminals on the AC and 
DC sides.

If the power supply is well designed, the voltage regulators will be 
referenced to the 0 V trace close to the DC output terminals.  The 0 V 
terminals on the AC side will be noisy relative to the DC side.  So, we 
want to tie the clean side to ground, not the noisy side.

-- John Chester