In article ,
Arny Krueger wrote:
Isn't 600 ohms the standard source impedance for audio production?

Not for a long time - unless possibly using a balancing transformer,
which is rare these days.

Electronically balanced outputs are more likely 50 ohms.

Of course if you were driving into several miles of twisted pair, 600
ohms in and out still holds good.

--
*He who laughs last, thinks slowest.

Dave Plowman London SW
To e-mail, change noise into sound.