I really like modules with tubes, like the Safety Valve (VCA). I am trying to find other schematics for modules using a tube. However, all schematics I am able to find require a high voltage (more than 100V). Therefore, are there any other low voltage tube schematics out there? Perhaps a tube oscillator? Thanks!
The only other one I know of is this one :
But I guess there must be more on the guitar FX sites…
You might want to branch out to the guitar pedal forums. There are several dezigns that use tubes.
There are some pensize low voltage tube from Russia (and elsewhere) like the 1SH2B or US type 6418. Many of the low volatge tubes are however noisy and suffers from microphonia.
But check Frag Jan Zuerst for these gems!
Also the journal Elektor Electronics ran a few articles on running “normal” tubes on low voltage, like EL84, EL509. Guess there was one or tweo articles that ran 2004, but I am not sure … I can have a peek. Hang on …
Nope! Couldn’t find neither the journals nor copies of the articles. But the idea was to run HV tubes on LV, but special considerations had to be made.
When or IF I find the papers I’ll be back.
Check Elektor as there are some articles on the subject:
https://worldradiohistory.com/UK/Elekto … 003-10.pdf Page 21 - headphone amp
https://worldradiohistory.com/UK/Elekto … 003-09.pdf Page 16 - various ideas how to rund tubes on low volatge.