zvex Sho distortion

[TimWaldvogel]

Well radio shack sells 12v zeners and some 4148 diodes, would those work?

[TimWaldvogel]

Is there a way somebody can illustrate the "newer version" with the Zener diodes? Or can I just buy some4148s from radio shack and do it like the perf layout says?

[soggybag]

The zener protection is done by adding the zener across the gate and source. Take a look at Jack Orman's Mosfet boost.

[TimWaldvogel]

Well idk how diodes work as voltage protectors, what is so flawed about the two diodes on the original SHO layout? And how if the voltage of the diode important, like you said use 9v zeners, would 12v zeners be bad or Jack with the tone? And why wouldn't the 1n4001-1n400x's barrel diodes work? 4148s?

[cpm]

Well idk how diodes work as voltage protectors, what is so flawed about the two diodes on the original SHO layout? And how if the voltage of the diode important, like you said use 9v zeners, would 12v zeners be bad or Jack with the tone? And why wouldn't the 1n4001-1n400x's barrel diodes work? 4148s?

a 9v zenner will start conducting backwards when there is more than 9 volts, this way there will never be more than 9v across the mosfet gate-source. Mosfet gate-source may be rated to some maximum voltage, beyond there is risk of destruction, so anything that will limit below that maximum will be fine (12v zenner may be ok too). Note that an electrostatic discharge can be 100s of volts

with the diode pair across rails you hope that a positive overvoltage gets its way through the diodes into the power rails.
i think of this situation: put some big voltage there, when the supply is not connected (then the positive rail is floating, not grounded), lower diode from ground is reversed, and the ground line is actually grounded (eg through guitar cords), the voltage will be applied to the mosfet gate with the risk of killing it.