Tubes at low +B...

[Alastair E]

Has anyone else tried various valves at say, only 12V +B....

Not the special 'Space-Charge' types, but common ones like the 6DJ8

I have done some low-voltage experiments all based on 12V +B, and was very surprised what can be done with ordinary valves....

[owen]

Then you'll be even more suprised what valves designed for car radios can do



Owen

[Alastair E]

Originally posted by owen
Then you'll be even more suprised what valves designed for car radios can do



Owen

I can imagine...

Heaters, 12V....

+B, regulated 6V...

[Nordic]

I'm jst putting the last few touches to it, but I am basicaly just finished with one... will post in the morning, little tired now...
But it basicaly runs of 9V B+ and 9V cell on cathode.... ecc88/6dj8/e188cc/6922 with opamp as output stage...

[Alastair E]

Have you seen this, I posted it under a different thread while trying to help out a guy with a baulky Tubalizer device....

[aletheian]

Originally posted by Alastair E
Has anyone else tried various valves at say, only 12V +B....

Not the special 'Space-Charge' types, but common ones like the 6DJ8

I have done some low-voltage experiments all based on 12V +B, and was very surprised what can be done with ordinary valves....

I have chimed in on eht other threads, so maybe this is redundant, but I'll expand on what I have tinkered with.

in terms of linear audio amplification, i have had good luck with the 6922 family as low voltage impedance buffers in front of solid state circuits, running off the SS PSU. I have built up a couple preamps and buffers for my SS power amp, and my computer soundcard that run on very low voltages, and in front of some chipamps and they worked out quite well. They were not clinically clean, but the harder sounding 6922's hit you with enough 3H that the increased 2H is not too mucky... in other words... distortion specs aside, it SOUNDS good to me. I have also used the same circuits with an output transformer for a balanced output.

For purposely trying to "tube up" the sound to approaching smarta$$ levels, I have run ecc82 a low volts, which gives horrendeous distortion figures, but sound really 'fat'. I used that for signal processing in a DAW, not hi-fi, so the nonlinearity was the point. Ecc81 worked as well, but not ecc83... at all.

I have also built up a few musical instrument amps with voltages that low. that is fun to tinker with. The voltage swing is the biggest limiting factor. since hot guitar pickups and bass pickups can hit around 9v peak or more just by themselves.

[Eli Duttman]

The 6GM8/ECC86 is a close relative of the 6DJ8/ECC88 intended for low voltage service.

6GM8 data sheet here.

While it definitely will work with 12 V. B+, you can't swing much of an audio signal. With B+ of about 25 V., you can do some good things.

[aletheian]

Originally posted by Eli Duttman
The 6GM8/ECC86 is a close relative of the 6DJ8/ECC88 intended for low voltage service.

6GM8 data sheet here.

While it definitely will work with 12 V. B+, you can't swing much of an audio signal. With B+ of about 25 V., you can do some good things.

I just ordered a pile of those things. You can find them cheap at online surplus places.

[Wavebourn]

Collins R-392 receiver works from 28V and uses particularly 6AK5 and 12AX7 tubes.

[HDaudio]

Originally posted by Alastair E
Has anyone else tried various valves at say, only 12V +B....

Not the special 'Space-Charge' types, but common ones like the 6DJ8

I have done some low-voltage experiments all based on 12V +B, and was very surprised what can be done with ordinary valves....

Hi Alastair E !
I undesrtand you have power stranfomer out with 12VAC, if you have 12 - 0 - 12 vac,and now we have 24 - 0, then put two diot and we have 24vac x 1*4 *2 = nearly 60 vdc , remember dont forget capacitor and do C-R-C about 50VDC, we have B+ verygood for 6922, and 182cc,.6C4..v use IV for DAC, preampli. v.v.
For heater we do R+R+R and x+x+x= number VDC from X ( R) go down from B+.
Same here :
Goodluck !