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

[John Chester]

On 12/2/23 12:21 PM, Bob Katz via ProAudio wrote:

> Naturally, I started a firestorm on facebook asking a question about 
> grounding in a headphone amplifier I'm building. 


A ground loop running through both the headphone amp and the power 
supply board doesn't seem like a good idea to me.  Here's my revision of 
your diagram:

https://photos.app.goo.gl/gWfABiqTc82mKZLV9

I wouldn't opine on whether the ground loop will upset the power supply 
without seeing both the power supply schematic and the PC board layout 
-- assuming it's not a potted blob.  Best to just get rid of the ground 
loop.  Zero volts to chassis ground should be on the DC side of the 
power supply, never on the AC side.

Zero volts to chassis should occur before the zero volt line gets to the 
headphone amp, not after.  IMO the most cautious approach to power 
supply wiring would be to run 3 twisted wires from the power supply to 
the chassis ground point, where the zero volt line gets connected to 
chassis, and then continue with 3 twisted wires to the headphone amp board.

-- John Chester