[R-390] R-390 power supply

[Perry Sandeen]

If one traces the R-390 PS output from the 26Z5
tubes you will see that it goes to C101, a 10 uF capacitor which is mounted on
the front panel and is wired as a capacitor input circuit.  This aids in raising the B+ to about double
of what is needed.
 
Replacing C101 with a C354 Dynaco Choke replacement
from Triode Electronics  for $17.00 and
rewiring the circuit to a choke input will substantially reduce the B+ to a
more moderate level.  There is also
enough space to add a modern Nihicon or equivalent filter capacitor of 100 uF
or more to the output side of the choke.  It would also be prudent to put a 100 ohm 1/2 resistor in series to the
choke input to limit input surge.
 
Regards,
 
Perrier Heretic-In-Chief







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