[sdiy] Tube!

[René Schmitz]

David Moylan schrieb:
> I've read that starved tubes voltages give 'exagerrated tubiness' but 

read as: very nonlinear transfer characteristic. Easily overdriven.
You can hardly drive these with more than a volt without banging the 
grid into conduction on the positive half of the cycle and cutting the 
tube off completely on the negative side.

IMO a single 12V starved tube stage doesn't cut the cake. Been there 
done that. I went to the higher voltages. There are some tubes (the 
subminiature ones i've used in my tubesynth) that were designed for 
plate supply voltages in the range of 80-120V, they give you a lot more 
headroom / dynamic range, while the staved mode is really no more than a 
fancy grid clipping distortion device.
For a preamp you don't really need the 250V, its only that mostly they 
were originally paired with a power amp, which requires this kind of 
voltage to deliver a serious output power.

> can't say I have any experience there.  If you have access to the low AC 
> voltage from the secondary of the power transformer you could do like 
> Paia did and use a voltage multiplier to up the voltage a bit.  I think 
> they went to 48V??

You could also use a transformer in reverse on that low voltage AC.

Cheers,
  René

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uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159