kevin gilmore
Señor Stax. Señor MAXX.
Can Jam '10 Organizer
- Joined
- Jun 21, 2001
- Posts
- 3,019
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- 996
After a recent accident where someone built an electrostatic amplifier and then
modified the bias voltage generator to get 580V into a 10M load (the DVM)
and then removing the DVM and almost frying the headphones...
Here is a simple and more than 1% accurate way of measuring the bias
at the stax jack without expensive or antique equipment.
http://gilmore.chem.northwestern.edu/electrostaticbias.pdf
This requires the DVM to actually have a 10M input resistance, which
almost all new meters do, but once they are damaged by significant
overvoltages that 10M input resistance is usually a lot lower.
Use the mouser parts listed. Less than $10
put the DVM on the 1 volt scale, 580V will read 580 milivolts
modified the bias voltage generator to get 580V into a 10M load (the DVM)
and then removing the DVM and almost frying the headphones...
Here is a simple and more than 1% accurate way of measuring the bias
at the stax jack without expensive or antique equipment.
http://gilmore.chem.northwestern.edu/electrostaticbias.pdf
This requires the DVM to actually have a 10M input resistance, which
almost all new meters do, but once they are damaged by significant
overvoltages that 10M input resistance is usually a lot lower.
Use the mouser parts listed. Less than $10
put the DVM on the 1 volt scale, 580V will read 580 milivolts
