Balanced in phono stages preamp?

A balanced electrical interface is almost immune to spurious signal pickup: eg: hum. When using single ended interconnects I have never had a problem with noise pickup, but I have had a phono cartridge circuit pretend it's a radio. Balanced configuration makes more sense for a high gain phono input than for any other part of the system.

Actually, I do use some balanced wires, but this is because the equipment is pro sound stuff, and that's the way it is made. I have used some of this equipment single ended, and it worked fine that way also.

Ashly pro audio equipment uses what some would call "pseudo balanced" outputs. (Inputs are true differential balanced circuits).

In the "pseudo" configuration, the wire that would normally (in a single ended interface) be ground is isolated from ground by a resistor of the same value as the output impedance of the active circuit, in my case 100 ohms. This wire is carried to the (-) differential input of the following electronics, along with the signal wire (+), and a ground wire. This scheme will give the same imunity to noise pickup as a "true" balanced output. This approach could be used with a phono signal if the preamp had a true differential input.