Is anyone aware of a full wave vacuum rectifier with a forward drop greater than that of the 5Y3?
5R4 is like 63 or 67 compared to the 50 of the 5Y3 I beleive. I used them once when my B+ was a little high in a SET EL34.
I guess it depends on the load. My RCA handbook shows the 5Y3 dropping 50v @ 125mA, and the 5R4 dropping 67 @ 250mA. Are you actually simulating?
5W4 is about the same (45V drop at 100 mA), maybe a few volts more drop than 5Y3. But it's only rated for 100 mA maximum. The 5R4 drops about 30V at 100 mA, according to the curve on the data sheet.
Thanks, Tom! The 5W4 is exactly the sort of thing I'm interested in.
A Heath AA-161 carcass that's already missing the O/P trafo is being converted into a full function stereo preamp. The 6.3 VAC filament winding of the AA-161's power trafo can power a DC supply for 2X 12AX7s and 2X 12B4s. Choke I/P filtering the "raw" AC should yield something quite suitable for driving a LR8 regulated 250 VDC phono section B+ supply. A gyrator after the initial LC section will dump some Volts prior to powering the line stage. Less IS more, when it comes to dropping resistors
The 12B4s are CCS loaded at 20 mA. and an unbypassed 500 Ohm cathode bias resistor is used. I don't want to overstress the CCSes.
A Heath AA-161 carcass that's already missing the O/P trafo is being converted into a full function stereo preamp. The 6.3 VAC filament winding of the AA-161's power trafo can power a DC supply for 2X 12AX7s and 2X 12B4s. Choke I/P filtering the "raw" AC should yield something quite suitable for driving a LR8 regulated 250 VDC phono section B+ supply. A gyrator after the initial LC section will dump some Volts prior to powering the line stage. Less IS more, when it comes to dropping resistors
The 12B4s are CCS loaded at 20 mA. and an unbypassed 500 Ohm cathode bias resistor is used. I don't want to overstress the CCSes.
A couple of good references on tube rectifiers:
http://www.suertenich.com/html/audio/rectifier.html
http://www.guitaramplifierblueprinting.com/rectifiers.html
BTW; I have a chinese tube-riia that use a double triode as rectifier...(6N6) - would it not be better to rewire/use a EZ80/81?
(even when it's output will be dangerously close to the rated 350V)
Arne K
http://www.suertenich.com/html/audio/rectifier.html
http://www.guitaramplifierblueprinting.com/rectifiers.html
BTW; I have a chinese tube-riia that use a double triode as rectifier...(6N6) - would it not be better to rewire/use a EZ80/81?
(even when it's output will be dangerously close to the rated 350V)
Arne K
Arne,
You should be fine using an EZ80/6V4. Just be sure to hold the value of the 1st filter cap. down below the absolute max. allowed.
The 6n6p data sheet shows a 750 mA. heater draw. The EZ80 data sheet shows a 600 mA. heater draw and a 350-0-350 design center voltage limit. Design center ratings are very conservative and exceeding them somewhat is usually quite safe.
You should be fine using an EZ80/6V4. Just be sure to hold the value of the 1st filter cap. down below the absolute max. allowed.
The 6n6p data sheet shows a 750 mA. heater draw. The EZ80 data sheet shows a 600 mA. heater draw and a 350-0-350 design center voltage limit. Design center ratings are very conservative and exceeding them somewhat is usually quite safe.
Hi!
I thought I'd use this thread although the question is a little different;
I got a power tranny without a centretap on the sec. winding,
but I'd still like to use tubes for rectification.
Can I use two full wave rectifiers (EZ81's for instance) and
place them in a four-diode-Greatz-bridge-way ?
😕
Cheers,
Empee
I thought I'd use this thread although the question is a little different;
I got a power tranny without a centretap on the sec. winding,
but I'd still like to use tubes for rectification.
Can I use two full wave rectifiers (EZ81's for instance) and
place them in a four-diode-Greatz-bridge-way ?
😕
Cheers,
Empee
No, the EZ81 has a common cathode, so it can only half of the bridge - the other half needs the PLATES connected together, with separate cathodes. You COULD use two 6BY5s, which have two diodes with no internal connections - but why not use a hybrid bridge? There's no solid state diode recovery noise, since there's a vacuum diode in series. And half the voltage drop, better regulation, etc.
Thanks !!
I understand what you say,
(after I drew it on a piece of paper)
😉
I will use the hybride design...
Cheers,
Empee
I understand what you say,
(after I drew it on a piece of paper)
😉
I will use the hybride design...
Cheers,
Empee
Eli's question has been answered, but just a word of warning about an "ouch!" I got some time ago.
That is about a Russian 5Y3GT I found, well and properly marked - but with an indirectly heated cathode inside! The voltage drop was quite lower than for the real thing. What the devil it actually was in USA terms I don't know.
That is about a Russian 5Y3GT I found, well and properly marked - but with an indirectly heated cathode inside! The voltage drop was quite lower than for the real thing. What the devil it actually was in USA terms I don't know.
Johan,
The 6087/5Y3WGTB and 6106 are US 5Y3 variants with cathode sleeves. Forward drop for those 2 may somewhat less than usual for a 5Y3.
GZ30 and 5Z4 could be looked at too.
The 6087/5Y3WGTB and 6106 are US 5Y3 variants with cathode sleeves. Forward drop for those 2 may somewhat less than usual for a 5Y3.
GZ30 and 5Z4 could be looked at too.
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