Grounding with separate enclosures

[CfM]

Hi,

until now all amps I built stay within one enclosure shared by power supply and amp. The mains earth is connected to the enclosure and signal ground is connected with the enclosure/earth via a resistor or thermistor.

But what to do if amp and power supply stay in different enclosures?
1) Connect mains earth to the power supply enclosure, don't wire earth to the amp and connect signal ground to the amp enclosure.
2) Connect mains earth to the power supply enclosure, wire earth to the amp, connect mains earth to the amp enclosure, connect signal ground via resistor/thermistor.

Which option is to be preferred?


Greetings,
Chris

[Eva]

Why two enclosures?

[CfM]

Originally posted by Eva
Why two enclosures?

There are two reasons. First reason is to get the transformer far away from the signals, second reason is that sometimes there simply isn't enough space in one enclosure (which applies for my Ono clone ).

Greetings,
Chris

[TechGuy]

Simple Option: Carry over both ground lines (Main and signal). Repeat method using the first enclosure.

[infinia]

Do option 1) if you don't care about EMI/RFI otherwise use option 2.) with isolated inputs and single star point chassis ground.
Make sure in either case, safety is number 1 and try to minimize any return currents (noise) through earth/metal case/shield. This includes 2a) Do not use input resistors to case ground, 2b) Use a single connection from the small signal gnd to caseground.