After doing some research on grounding and shielding I have been left with a few doubts about the system I used so far
From what I had thought the safest practice when wiring a piece of audio equipment with balanced input and output connections, is to have the input/output cables shields are connected to chassis earth on pin1 of each xlr connector. Within the enclosure, shields are left unterminated where the cable connects to the circuit, thus shields are not connected to the 0V signal of the circuit and are basically only used to screen the signal cables from noises. The 0V signal of the circuit is connected to chassis earth at one point only within the enclosure, usually at the power supply.
Someone pointed out to me that more complex installations require the use of a technical ground connection, to route the 0V signals to earth on a dedicated path.
From what I understood in order to do this the 0V signal must have an available connection on the outside of the unit. This is insulated from the chassis (an insulated terminal post for example) as it's going to be routed to earth through a dedicated wire.
But if the unit is also to be used in standard installations (without technical earth), it must have the option to connect 0V to ground within the enclosure, so usually it's best to add a ground lift switch to have both options available.
What I did not understand, if having this technical earth facility also implies that pin1 on the input/output connectors must be left unconnected from the chassis. If that's the case, do the input/output shields need to be connected to the circuit 0V instead ?
From what I had thought the safest practice when wiring a piece of audio equipment with balanced input and output connections, is to have the input/output cables shields are connected to chassis earth on pin1 of each xlr connector. Within the enclosure, shields are left unterminated where the cable connects to the circuit, thus shields are not connected to the 0V signal of the circuit and are basically only used to screen the signal cables from noises. The 0V signal of the circuit is connected to chassis earth at one point only within the enclosure, usually at the power supply.
Someone pointed out to me that more complex installations require the use of a technical ground connection, to route the 0V signals to earth on a dedicated path.
From what I understood in order to do this the 0V signal must have an available connection on the outside of the unit. This is insulated from the chassis (an insulated terminal post for example) as it's going to be routed to earth through a dedicated wire.
But if the unit is also to be used in standard installations (without technical earth), it must have the option to connect 0V to ground within the enclosure, so usually it's best to add a ground lift switch to have both options available.
What I did not understand, if having this technical earth facility also implies that pin1 on the input/output connectors must be left unconnected from the chassis. If that's the case, do the input/output shields need to be connected to the circuit 0V instead ?
