[SignalOne] The CX7A Saga Continues

[jerry]

This time, after removing the TDA2030A and reconstituting the +34V with 
a proper high voltage
3-terminal regulator, the +15V died.  The symptoms were a buzzing from 
the power transformer, and
R22 getting hot to trot.

   That regulator had shorted internally - the input had shorted to 
ground.  So I'm going to replace
it.  This time, with a proper output bypass and a protection diode 
between the input & output.  ALSO,
this is a genuine part from Mouser, not the QA reject stuff from Amazon.

   I've been thinking of going switching.  Murata has a series of 
3-terminal switching regulators.  They
are exact replacements for the TO-220 items, just as small.  And...they 
don't make heat.  I could mount
them right on the circuit board.  Murata knows what they're doing, and 
these are decently quiet.  I used
them in my T41 homebrew project, can't hear them at all.  They cost 
about $5 per each.

                  - Jerry, KF6VB