[R-390] Microphonic Parts?

[Roger Ruszkowski]

Fellows,

We do accept that a tube will go microphonic. Some of us have experienced a solder joint or mechanical connection that has gone microphonic. Not a common problem but resistors can go microphonic in the same way as a mechanical joint does it. The resistance strip in the device has a crack and is sort of open. But you do get an open reading with a low current test meter. But in fact the part has a mechanical defect. You just can not get to the defect and make an examination. You can get a break in any part where the leads open internal to the device or some internal part cracks / breaks open. You do not get a gap at the break that gives you an open failure. So it may act microphonic.

Roger AI4NI