I am thinking to change the diode bridge to tube rectifier.
211 tube amp, 1180v dc on anode at 65mA
The PSU have :
0 - 900V AC ( not centre tap) for both channels
0 - 5v 4A x 2
What will be the best implementation.
211 tube amp, 1180v dc on anode at 65mA
The PSU have :
0 - 900V AC ( not centre tap) for both channels
0 - 5v 4A x 2
What will be the best implementation.
I have been putting aside parts for an 845 Amp (one of these days) which I intend to run at a B+ of 1200V or more. I have a 1050-850-0-850-1050 power tranny rated at 300mA (way more than needed) for it, and have set aside some 5R4 rectifier tubes which have a PIV rating of 2800V.
Those tubes have a very small maximum capacitor value so the supply needs to be a choke input or a CLC with not more than 4uF as the first cap.
TDSL Tube data [5R4-G]
You might also look at some damper diodes which have high PIV ratings.
Cheers,
Ian
Those tubes have a very small maximum capacitor value so the supply needs to be a choke input or a CLC with not more than 4uF as the first cap.
TDSL Tube data [5R4-G]
You might also look at some damper diodes which have high PIV ratings.
Cheers,
Ian
A pair of 866As?
866A - Wikipedia, the free encyclopedia
-Pat
ETA - never mind - you'd need four of them in a full wave bridge. I just re-read and see you have a non center tapped transformer...
866A - Wikipedia, the free encyclopedia
-Pat
ETA - never mind - you'd need four of them in a full wave bridge. I just re-read and see you have a non center tapped transformer...
To continue using the power trafo mentioned, bridge rectification is necessary. I suggest you use a hybrid bridge, with SS diodes forming the ground connection and a pair of plates in parallel 5AR4s forming the "hot" connection. 4 A./5 VAC is enough to support 2X 5AR4s. Forward drop losses will be greater than a 100% SS bridge, but will not be horribly greater.
BTW, series wired pairs of UF4007s will be fine on the SS side of the hybrid bridge.
While a 100% vacuum diode bridge is possible, complications in the filament supply and doubled vacuum forward drop losses argue STRONGLY against such a choice.
Well de idea is more or less as this:
But I don´t know if 2 x 5r4gyb (plate parallel) can support the capacitors load or how to calculate the maximum capacitor load of the rectifier tubes.
But I don´t know if 2 x 5r4gyb (plate parallel) can support the capacitors load or how to calculate the maximum capacitor load of the rectifier tubes.
The cap. is too large for 5R4s, as 20 μF/bottle is the limit. Also, the forward drop in 5R4s is very large. Change to 5AR4s and you'll be fine.
If you put the choke between the two negative sides of C1 and C2 the voltage winding/core is less high, safer.
For the diodes the BY228 can stand the high voltage.
Mona
For the diodes the BY228 can stand the high voltage.
Mona
Consider 5c8s(5z8C), usually used w/the GM70.
By chance this amp is the MingDa 211??
for me the best ( price/sound/durability ) is 5r4wgb but I am not sure about if the PIV is enough I am going to buy the Chinese 5z3p to try the first also the mercury rectifier tube are pretty glow tubes
The amp is my own design.
Maybe you have seem in the other post about the OPT square waves
HERE
The soviets made some high voltage diodes that look sort of like a snickers bar with leads coming out the end. I had thought about using those at one point for a high voltage project but just never got around to it. You can look on the usual auction site and search for them if you are interested in going that route.
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