I am currently testing out a full wave quadrupler power supply, using a 65VCT 2A power trannie extracted from a dead "dumpster carcass" Sony receiver.
The quadrupler uses four 1N5408 rectifiers, and four of the 220 uF / 250V electrolytics, as were used in the early A and B versions of the ST35, and Ike boards.
I added more filtering, with a C354 choke and a 470 uF 400V cap, and the B+ ripple is about half a volt, under the 200 mA loading.
in an actual amplifier design, the current consumption would be less, probably 100-150mA, maximum.
Using a 40W 230VDC light bulb as a load, I get 295VDC at 200 mA into the bulb (yeah, it runs very bright, acts like it thinks it's a 60 watter).
At the input side of the choke, the DC voltage is approx 305VDC, which is correct considering the choke's DC resistance (53 ohms)and appx 200 mA current,
for a 10VDC drop, thus the 295 VDC output, under load conditions... No load DC output is appx 350VDC (just a 270K 2W bleeder resistor load)
Right now, it's just a "breadboard" prototype , until I can determine that it will hold up to long-term operation without premature cap failures.
So far, I have found no problems withthe two "input" caps heating up much above room ambient temperature.
The full wave quadrupler was adapted / modified from the circuitry shown inthe 1956 - 1960 ARRL Amateur Radio Handbooks.
In its simplest form, it looks like this:
With the four electrolytics, the positive side is the top, I used 220 uF / 250V caps, and 1N5408 rectifiers.
This, in turn feeds into a C354 / Hammond 156R choke, and a 470 uF / 400V cap, with a 270K 2W bleeder resistior.
For filament power, I'll use a Rat Shark 12.6VAC, CT, 3A transformer that I have on hand.
It's a work, still in progress
Update 1-20-2013: I mounted it all onto a bamboo 6.25 X 13.5 inch "breadboard", found at the local "dollar store". Same as I used for the "Uglytron" 6SL7 / 6L6GC
"super-champ" guitar amp experiment. No more "flying" leads, clip lead jumpers, and impending shock hazards
If all of this works out, then I have a really
huge 72VAC CT & 12VAC CT power trannie which I found for a few bucks at a hamfest about ten years ago,
it's about 12 pounds of heavy iron and copper, at least.
I have some hefty, good quality electrolytics which could work with it, as well as some beefy
10 Amp "stud" type rectifiers, for the beast-zilla version of my prototype quadrupler PSU.
With your big 1 KVA Crown power trannie, the quadrupled DC output voltage, under load would achieve up to 480VDC, but the current will be significantly
less than 2.5 amps, because of the losses and conversions of the voltage multipliers. I'd SWAG no more than one amp peak, perhaps 500-600 mA continuous duty,
which is still pretty darn impressive. And somewhat dangerous, be careful...
No load output voltage could exceed 670VDC (120VAC X 1.414 X 4), so plan accordingly with the electrolytic capacitors' DC voltage ratings.
/ed B