what you should really be asking is for solutions for derriving your b+ voltage. If I remember right in old days they used what they called a vibrator. It generated a low ac voltage which is then fed to a transformer to get your high voltage. In modern compoments best choice is probably a switching psu, which is what ss amps for cars use to get there voltages.
A DHT would need some very serious shock absorbing mounting not to chime and groan reading the road.
You can, but given the fragility of the filaments it is unlikely that they will last long even with fairly draconian measures at isolating the 2A3 from road shocks. I figure one good pot hole is going to be good for an open filament or two..
Then there is the question of speaker efficiency vs available power, there is a good reason why most car stereos with any pretense at quality are capable of delivering at least 15W per channel into a 4 ohm load. A pair of 2A3 in PP could give you that kind of power, but frankly the 6BQ5 in UL would be a much better choice.
Submini types can be used everywhere else to keep size moderate and are often designed for high shock environments. (6021, 5719, 5902, 5903, etc.)
Good luck!
Then there is the question of speaker efficiency vs available power, there is a good reason why most car stereos with any pretense at quality are capable of delivering at least 15W per channel into a 4 ohm load. A pair of 2A3 in PP could give you that kind of power, but frankly the 6BQ5 in UL would be a much better choice.
Submini types can be used everywhere else to keep size moderate and are often designed for high shock environments. (6021, 5719, 5902, 5903, etc.)
Good luck!
...or accept that the technology has moved on and that just because you can doesn't mean you should.
Dunno what the ambient noise level is inside your car under real-world conditions, but I'd estimate it at upward of 24db noisier than your home at best. Idling. Air on or off.
Now do your required power calcs....
This looks like a case of wrong technology for the application to me.
Dunno what the ambient noise level is inside your car under real-world conditions, but I'd estimate it at upward of 24db noisier than your home at best. Idling. Air on or off.
Now do your required power calcs....
This looks like a case of wrong technology for the application to me.
Thoriated tungsten filaments become very brittle once used (the crystallic structure changes because of the heat); indirectly heated tubes would be much better for this purpose.
For the serious builder, a modified 12V->230VAC car SMPS will easily deliver the required plate/heater/bias voltages.
Kenneth
For the serious builder, a modified 12V->230VAC car SMPS will easily deliver the required plate/heater/bias voltages.
Kenneth
The original car radios used tubes, there are several tubes that can run 10-14V on the heaters and up to 25V on the plates. Combine those with some higher sensitivity speakers and you might be ok, it would be interesting to try.
The other option would be to look at military tubes that were designed for Avionics, as those should be able to withstand some shock and abuse and still function adequately.
Also the Milbert amp, designed by David Berning has successfully marketed and still sells it's 30W per channel tube car audio amp, course it's expensive.
The other option would be to look at military tubes that were designed for Avionics, as those should be able to withstand some shock and abuse and still function adequately.
Also the Milbert amp, designed by David Berning has successfully marketed and still sells it's 30W per channel tube car audio amp, course it's expensive.
Everybody....Thanks U very much for the response.....(sorry for my bad english)
before i post this question... , i allready made the smps 6sn7+2a3, and it work,
and sound better than... USD$25000 car power amplifier(mosfet or hybrid),
it drive my fostex 6" fullrange & fostex dome tweeter (at 92.5db/w/m)
yes it's powered via SMPS...(a good China SMPS Inverter+custom ferrite trans )
all power supply &fillament is DC regulated.
but i'm still confusing,...was fragile dht fillament vs shock and vibration
because i've been using that car amp about 2 years(1 hour/day), the 2a3 valve
still sound good (course i'm not using rca 2a3) i'm just using cheap china's 2a3,
i'm using sun audio 2a3 schem with little modification, 300V at 55ma
how long will my 2A3 will die/broke...?
before i post this question... , i allready made the smps 6sn7+2a3, and it work,
and sound better than... USD$25000 car power amplifier(mosfet or hybrid),
it drive my fostex 6" fullrange & fostex dome tweeter (at 92.5db/w/m)
yes it's powered via SMPS...(a good China SMPS Inverter+custom ferrite trans )
all power supply &fillament is DC regulated.
but i'm still confusing,...was fragile dht fillament vs shock and vibration
because i've been using that car amp about 2 years(1 hour/day), the 2a3 valve
still sound good (course i'm not using rca 2a3) i'm just using cheap china's 2a3,
i'm using sun audio 2a3 schem with little modification, 300V at 55ma
how long will my 2A3 will die/broke...?
I'd say if you've been doing this for a year already you would know the answer to that question far better than any of us.
Since it is a done deal I would just make sure you have spares for the day when a filament does finally break. Your roads must be a lot smoother than the ones around here. My 50 mile daily commute has rim smashing and tire destroying pot holes all over the place which I have memorized so that I can avoid hitting them with my car. (So glad I live in the developed world..
)
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i'll send the schem later, after draw it on pc,
now the amp still under modification, with vibration damper and shock damper with spring and little shock absorber (mcmaster.com),
and bolt in securely to body of the car. and later i wannt to take a sensor from the fuel pump/ oil pressure sensor, when engine off or car crash, the high voltage will switch off and fast bleeding via low resistance.
thanks for the input and critic, i need that, for better diy project,
now the amp still under modification, with vibration damper and shock damper with spring and little shock absorber (mcmaster.com),
and bolt in securely to body of the car. and later i wannt to take a sensor from the fuel pump/ oil pressure sensor, when engine off or car crash, the high voltage will switch off and fast bleeding via low resistance.
thanks for the input and critic, i need that, for better diy project,
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