Question about diode function

[jflam]

I tested my diode and I got these values

.65v with negative lead on the cathod

1.18v with it reversed.

My MM instruction manual tells me that with these measurements, it is bad.

I also measured it with it powered and it reads 7.6v with neg. lead on the cathod, pos. lead on the anode. Shouldn't this be 9.1v like it is rated?

Could this cause my FF to play without fuzz?

[Jason D]

As far as I understand it, when a diode is foward biased, going with the flow of current there is a voltage drop. About 0.7v for silicon diodes, 0.3V for Ge. If it is reversed biased, oriented opposite the flow of current, it stops current from flowing. Kinda like a one way valve.

Since you are  talking about one rated for 9.1v, I would think you have a Zener diode.

Zener diodes are usually used as voltage regulators and limiters. A zener maintains a constant voltage no matter what the current is (within specified limits).

[Jason D]

Also what version of the Fuzz Face did you build that uses a diode?

[jflam]

The diode is for the JH-2 Jimi Hendrix fuzz face (it uses a zener 9.1v).

[b_rogers]

its a reverse polarity protection diode hes talking about i think..

[Jason D]

yeah, the zener is just there for protection. the circuit will work without it. so you should still be getting fuzz. your problem might be somewhere else.