"Phil Allison" wrote in message
...

** Techs often get a sinking feeling when they discover a burnt AC power
transformer in a device. The unit simply blows fuses at switch on and
cannot be seen to work at all - so maybe it has other serious faults.
Also, exact replacement transformers are often not available or else
involve a long wait and high cost.

Had one this week, a baby size 6VA tranny in the PSU for a new looking "
Mojave" valve microphone. The PSU has an IEC inlet and a switch for 115V
and 230V AC power - some goose had tried to use it with 240VAC and the
switch set to 115V !!!

The burnt tranny had two secondaries, 9V at about 300mA and 120V at about
25mA - so nothing off the shelf would do. The local importer was blaze
and any replacement would involve a long wait. The PSU case is very
compact, so it was simply impossible to fit two transformers to get the
required voltages.

The tranny looks similar to the one in this pic:

http://www.chinatransformers.cn/User...5004507496.jpg




Was this the PSU?

http://i47.tinypic.com/144ch4.jpg


Both PSU's for both Mics in this picture are identical internally, apart
from one has different value Zeners to produce the HT for the different
mics.

In this case the PCB's are both marked at 9v5AC and 200v AC at the TX
inputs.
The S.E. Electronics one has a shorted primary (One Zener dead also).

Just wondering if all these cheapo tube mics are all made in the same
factory.



Cheers,

Gareth.