Has anyone tried using two 6AS7/6080 dual regulator tubes as pseudo diodes in a fullwave bridge rectifier?
As I can see these tubes should be quite suitable for this, they have low Rp, high max. cathode current and high heater-cathode isolation voltage.
The reason I came up with the idea is that I have some power transformers with high current 6,3V windings and non-CT HV windings.
Using silicon rectifiers together with those transformers would result in an unusable high voltage, besides I want my tube amps to be as free from silicon contaminations as possible
On second thought, I guess one 6AS7 would be enough if it is completed by two silicon diodes (a hybrid bridge rectifier).
OK, I know what I just wrote about silicon butwhat the heck...
As I can see these tubes should be quite suitable for this, they have low Rp, high max. cathode current and high heater-cathode isolation voltage.
The reason I came up with the idea is that I have some power transformers with high current 6,3V windings and non-CT HV windings.
Using silicon rectifiers together with those transformers would result in an unusable high voltage, besides I want my tube amps to be as free from silicon contaminations as possible
On second thought, I guess one 6AS7 would be enough if it is completed by two silicon diodes (a hybrid bridge rectifier).
OK, I know what I just wrote about silicon butwhat the heck...
I presume you'd be wanting to use a 5U4 for the positive half of the FWB, and the 6AS7 for the lower? In that case the cathodes will be bouncing up and down (alternately) with the full AC voltage.
Better to use damper diodes, which have more than enough heater insulation, at least in one direction.
Tim
Better to use damper diodes, which have more than enough heater insulation, at least in one direction.
Tim
???
Hi Tim ,
If a separate filament winding is used for the 6080 and is connected to the cathode , there should not be a problem with h-k , although sectional matching of 6080 do not seem too good . There was a lot of debate about 6080 in this application on the Joenet . I agree that dampers are excellent and inexpensive
316a
Sch3mat1c said:H-K insulation will be insufficient for much voltage.
Tim
Hi Tim ,
If a separate filament winding is used for the 6080 and is connected to the cathode , there should not be a problem with h-k , although sectional matching of 6080 do not seem too good . There was a lot of debate about 6080 in this application on the Joenet . I agree that dampers are excellent and inexpensive
316a
Dampers
Hello ,
As you're in Europe , try looking out for some PY500a . Mullards are excellent as are Tungsram which appear to use the same tooling but have welded anodes . There are literally tens of thousands of these available . These were used in the last generation of colour TV sets , replacements were manufactured well into the 1980's so I doubt these will run dry for several years ! Benefits include low volt drop , high current delivery , low price .
316a
Hello ,
As you're in Europe , try looking out for some PY500a . Mullards are excellent as are Tungsram which appear to use the same tooling but have welded anodes . There are literally tens of thousands of these available . These were used in the last generation of colour TV sets , replacements were manufactured well into the 1980's so I doubt these will run dry for several years ! Benefits include low volt drop , high current delivery , low price .
316a
Huh ?
Penny pinching and using valves which are cheap but have genuine advantages are two completely different things . I'm sure others out there can concur than PY500a is an excellent valve but I doubt you have tried them
316a
Joel said:"Low price" 316a? Are you penny pinchers trying to advance the state of audio or not?
Penny pinching and using valves which are cheap but have genuine advantages are two completely different things . I'm sure others out there can concur than PY500a is an excellent valve but I doubt you have tried them
316a
fdegrove said:Back to the 6080, sure you can turn any triode into a rectifier.
Just remember, as has been pointed out, you'd need to match this formidable dual triode and than use it as a rectifier.
Personally I'd rather put this excellent sounding valve to better use, after all there must still be tons of otherwise useless rectifier valve around...if ever that supply were to dry up than maybe, just maybe.
OTOH, it may be an interesting experiment nonetheless...provide both halve are reasonably matched.
Cheers,
I have some 7586 nuvistors , the only use for them I can think of at present is to turn them into cuff-links Class B is a topology I do not wish to dabble with , I do not need high power and would rather rely on a simple yet rugged power supply avoiding that nasty crossover stuff . Anyone wanting class b is welcome to it , I'll stick to pure class A
I wonder how a 6080 strapped as a rectifier would actually sound ? I'll have to dive through the archives on the Joenet to find out how the discussion there was concluded . With the cost of say a pair of EY84 , EY81 , PY801 or PY500a as mentioned I doubt it would be worthwhile even bothering trying a 6080 unless I was really bored
316a
Hi,
Being bored is must...
If you're listening to the PSU than something is definetely wrong with the design, wouldn't you say?
BTW, I've no idea what the current price is but about 10 years ago 7586s were sold to dealers at 100$ +/EA...fancy cuff-links indeed and you don't even see its' charming glow...must be a transnukestor?
Cheers,
With the cost of say a pair of EY84 , EY81 , PY801 or PY500a as mentioned I doubt it would be worthwhile even bothering trying a 6080 unless I was really bored
Being bored is must...
If you're listening to the PSU than something is definetely wrong with the design, wouldn't you say?
BTW, I've no idea what the current price is but about 10 years ago 7586s were sold to dealers at 100$ +/EA...fancy cuff-links indeed and you don't even see its' charming glow...must be a transnukestor?
Cheers,
Cufflinks
I have some expensive tastes ! Maybe I should do something really silly with the nuvistors : like using them as an amp input stage or heat them up with a blowtorch for ten minutes . They'd soon glow then !
316a
fdegrove said:BTW, I've no idea what the current price is but about 10 years ago 7586s were sold to dealers at 100$ +/EA...fancy cuff-links indeed and you don't even see its' charming glow...must be a transnukestor?
Cheers,
I have some expensive tastes ! Maybe I should do something really silly with the nuvistors : like using them as an amp input stage or heat them up with a blowtorch for ten minutes . They'd soon glow then !
316a
(has melted pennies together to make a glob of brass)
Hehe, where I live it is illegal to destroy money.
It´s government property or something like that
Nah, I checked the maximum heater-cathode voltage again and it wasn´t as high as I remembered. After all, it was just an idea.
Still I do have a few that I´ll put to use at some time.
When I think about it I have all the iron needed for a SRPP/parafeed amp similar to the one Robert Morin has designed.
Still I do have a few that I´ll put to use at some time.
When I think about it I have all the iron needed for a SRPP/parafeed amp similar to the one Robert Morin has designed.
Hi,
Go for it, seems like the way to go.
Cheers,
When I think about it I have all the iron needed for a SRPP/parafeed amp similar to the one Robert Morin has designed.
Go for it, seems like the way to go.
Cheers,
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