[sdiy] A simple 12AX7 vacuum tube tester schematic..

[mcb, inc.]

On Thu, 17 Jan 2008, Travis Shire wrote:

> You don't even need an audio signal. Just scope the plate (through a
> coupling cap) while thumping on the tube.

All this talk of testing tube microphonics brings an idea to
mind:  a thermionic interpretation of the Glasglockenklavier.
Small keyboard to whack carefully selected tubes with little
hammers and the resulting noise processed and sent out...

--
Monty Brandenberg