All changes have been kept two diodes (1N4007).
The placement of a bridge rectifier (4 x 1N4007) is a good choice?.
Problem with deleting the mass of filaments in PC6?.
Pictured, top original scheme, bottom diagram with 4 x 1N4007.
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Speaking about easy : replacing the 12x4 with 2 diodes is even easier, and neeeds no extra transformer.tubes4hifi wrote:super easier way to add a power transformer . . . . leave the existing power transformer to power all the existing tube filaments
EXCEPT that the new transformer will ONLY power the 12X4 tube (it needs 12vac @ 300ma). Don't forget to replace the pilot lamp with an LED,
that will save you another 150ma.
So originally the transformer needed to supply 750ma of current, now the old one will only need to supply 300ma plus 5-10ma for the LED !!!
This way you don't have to worry about converting anything else to DC.
BTW, the original PAS transformer puts out about 10.5vac (it's too gutless to put out 12vac with all the load on it) and you wind up with about 22-23vdc
to run the filaments in series connection. Once you relieve it of working so hard by powering the 12X4 separately with 12vac,
you'll wind up with about 24-25vdc which is perfect.