...with little or no consideration as to what that wire will do to isolation resistance or capsule sound.
The wire becomes part of the diaphragm, mechanically and electrically, so I would consider it critical.
Therefore I looked for one not too soft (to reduce movement which causes LF microphony), but not ringing, something that straight wire does.
In most constructions the cable contacts the housing somewhere, as we have 60, 120 or up to 200V bias on it, so high isolation is needed.
I have measured the isolation of several cables and found some to be sub-optimal (most work fine).
BTW: tube sockets and the tube itself may also have insufficient isolation, especially if dirty. Printed circuit boards need special isolation posts with direct wiring, soldering direct to the print does not work at all.
The thinner the cable is, the lower is the stray capacitance and other adverse effects.
Finally I used the inner wires of a Belden top quality, very thin balanced cable with good result.
My first tests with "just what is at hand" showed some of the problems mentioned above.
Regards
Kai
