Re: Ribbon Mic - RCA 77D - worth messing with????


danger wrote:

> Sorry I have about 15from 44a and 77a up and have never blown one

I've never won the lottery either. I guess we both have the same kind
of luck.

> please explain to me how the dc is going to fly over the transformer
> windings.

DC doen't couple through the transformer. It doesn't have to. A large
spike will do sufficient damage. When you plug in an XLR connector, pin
2 and pin 3 won't make contact at exactly the same time except by luck.
There's likely to be a couple of milliseconds between when the first
one makes contact and when the second one does. If the transformer
center tap is connected to pin 1, plugging in the mic with phantom
power turned on will apply the full phantom voltage across half the
winding until the other signal connects. A 48 volt spike will go
through the transformer quite nicely.

.

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