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Old 19th May 2006
Don't apply 48 volts to these. Any mismatch of the phantom distibution resistors will cause one end of the capsule's coil to be a higher voltage potential than the other, possibly frying the coil wire. Most phantom resistors are 6.81 k 1%. This could let around .25 volts difference from one end to another. If one matches these resistors to .1% that would keep the potential down to 25 mv or less.
The other effect would be to push/pull the capsule out of it's idle position, sort of like when dc offsets push/pull a speaker in a power amp.

Best to be attentive and keep that phantom switch off at all times.

Protect the Unidyne III's!

Jim Williams
Audio Upgrades