optimum conditions of a tube in a Tube Pre??

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3nity

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Joined
Dec 30, 2005
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3,637
Location
MTL, CANADA
What i means is heatingvoltage, plate voltage?? plate current??
A lot of budget hybrid preamps don't have 190-200 voltage but what if we could develope a mod to apply more than 12-48 volts??

Sorry what i know about tubes is on Tube guitar amps! :shock:
 
The 12AX7 likes to have some high voltage to play with. That is, if you're looking for solid and low distortion sound. I can't see using anything less than 150V on the plate (which could imply 300V to 400V supply).

The low voltage circuits many folks use require the tube to be run at microamps. Very high noise level, poor output drive, super distortion. But hey, for an effect pedal, that can be exactly what you want.

The secret to tube biasing is to find a point where grid current passes through zero.

jh
 

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