Can anyone comment on this, what do people think? I'd like to build something along the lines of this (2 or 4 channel, line level pre amps to run off 12V).
im also intrested in this (battery) subject
takamine has a preamp in there new guitars, a 12au7 tube running on six AA batteries (that's 6 volt). They claim it does some work, but not all the work of a 110/230v.
Vox, also has a preamp stompbox; a 12au7 running on 9 volt
I've searched the net for info or circuits using batteries with no luck.
can anyone help with links or info?
takamine has a preamp in there new guitars, a 12au7 tube running on six AA batteries (that's 6 volt). They claim it does some work, but not all the work of a 110/230v.
Vox, also has a preamp stompbox; a 12au7 running on 9 volt
I've searched the net for info or circuits using batteries with no luck.
can anyone help with links or info?
Re: im also intrested in this (battery) subject
That will be because valves need 100V to get going. If you deliberately want a valve to distort horribly, then you can run it at low voltage, but expect the results to be very variable and dependent on individual valves. Try a search including terms like "musician" "low-voltage" "valve" (or "tube") and "distortion".
tryff said:
That will be because valves need 100V to get going. If you deliberately want a valve to distort horribly, then you can run it at low voltage, but expect the results to be very variable and dependent on individual valves. Try a search including terms like "musician" "low-voltage" "valve" (or "tube") and "distortion".
EC8010 said:
Absolutely anything you like, I'm looking for a tube pre-amp to run of a 12V (car) supply, this is the only thing I can find so I just wondered what people thought of the design (well as much as you can comment on without schematics etc). I'd like to DIY something, I'm looking at building a VERY retro cd player for an old car, I'm talking Nixie tubes for the display and tube pre-amp, it would be based upon a SFF PC setup using a decent sound card but I just fancy some funky glowing tubes in there too. I'm thinking i really need a high voltage supply, and a very robust suitable valve, it would bea buffer not really need any gain as such. what can anyone suggest?
For a car... I did a search using "space charge" and one of the better results was the "Low voltage pre-amp" thread.
Puggie,
The 6GM8/ECC86 is your tube. It will work with "12" V. on the plate and it makes a decent cathode follower (buffer). Use a 3 V. coin cell for bias and a NPN BJT wired up as a CCS as the load.
The 6GM8/ECC86 is your tube. It will work with "12" V. on the plate and it makes a decent cathode follower (buffer). Use a 3 V. coin cell for bias and a NPN BJT wired up as a CCS as the load.
At low voltages, you can also use Nuvistors. Not easy to find these days, but no harder than space-charge tubes. Look for 6CW4, 8056, and the like.
thanks for the info guys, My knowledge fo tubes starts and finishes with swapping the 12AX7s and EL 34s in my marshall and the re-biasing the power stage. I know nothing of these strange numbers you are quoting me. any chance of more info using small words and big text for my little brain to comprehend???
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