Bush Dac 90 Capacitive Dropper

[Refugee]

Yes indeed the HT rectifier also rectifies the voltage across the dropper capacitor and will end up passing no currant. It will not work at all in isolation.
It may work a little bit with the heater chain in parallel but how well is another question all together.

[Aerodyne]

I've never seen or even thought of using a capacitive dropper for anything other than the heater chain supply, which after all is the main function of a dropper (ballast) resistor in most AC/DC sets. Along with a capacitive dropper for the heaters, a fixed resistor in the HT line or before the input to the rectifier is probably the simplest to lower the HT rail voltage, if essential in a set designed for 110V operation.
Tony

[tim.54]

Did a dummy run last night , seems to work fine , just need to work out were to put the parts , hopefully no more toasted back panel. thanks for everyones input.,
regards, tim

[tim.54]

        It`s been a while since i last posted plus i have had to change my user name (forgot password and have changed internet provider/email ) the dac 90 is up and running , sounds well , i`ve been busy with a AC91 and a few other things !
just thought i would post a couple of pics , i mounted the dropper in the original casing after disposing of the asbestos liner. thanks for everyones input.
regards, tim.

[AlanBeckett]

A splendid job, and it's good to see you back

Alan

[Geaney]

Looks terrific - must remember this technique next time I'm looking at installing a capacitive dropper.

Cheers, John