Hello all,
I got a second hand microphone the other day for recording interesting sounds on a little piano-key type mono tape recorder.
The mike is made by Grundig, model GDM 311 seems very well made, and looks like the sort your parents/grandparents might have used to record baby's words on the family reel to reel.
It has screen + 3 wires terminated in a 3 pin DIN plug, these are the outputs from some kind of matching transformer (I had a look) a low impedance side which seems to match the recorders input, and a higher impedance side. (I could only measure the DC resistance though)
So what I would like to know is, why the 3 wire arrangement? Is to provide an alternative match for a non standard input, or is it to provide some kind of offset earth connection - I'm guessing to feed a differential input.
Any suggestions, anybody? It would be nice to know even if I'm not going to use the extra wire.
Tia, Monster