[ragbor]

I have a relatively pedestrian knowledge of electronics, but was interested to know if I needed (as recommended in several articles I've seen from time to time) to put a 680 ohm resistor across the output terminals of my LA-3a, which has a low (600 ohms) input and output impedance, to properly match to my 192 I/O when using it as an I/O plug-in. I cannot find any specs which indicate the 192's input and output impedance anywhere. Supposedly, 'ringing' will occur if there is a mismatch, and I don't know if it's something that would be blatantly obvious or even exactly what 'ringing' sounds like. I'm imagining it's a resonance or edge-of-feedback kind of sound. Am I close? I don't hear anything like that, yet. Is it gain related or omnipresent if there is indeed a Z mismatch? And related to this issue, where should the impedance switch on the back of my UA 6176 be set to? Thanks for listening...