[Phil Allison[_4_]]

wrote:



the most important ground issues involve signals that enter and exit

1) the + and - leads from the wall wart should go directly to the
470 uf cap so that large ripple currents do not flow through any grounds.
I would also use the one point to tie the circuit to chassis ground.

2) the pin 1 connections for the XLRs should go directly to the chassis
so that any large ground currents do not flow through the circuit grounds.
You can google "pin 1 problem" to learn more about this.



** Mic pre-amps tend not to have that problem - since microphones are "floating" sources.

However, direct connection of pin 1 on the input XLR to case is advisable to prevent RF interference picked up on the shield of the mic cable entering the internal circuit.


.... Phil