Zener Diode

[robrhy]

Building a Fuzzdogs Phase 45 pedal.
BOM asks for a 5.1v zener diode but i only have 8.1v zener diodes.Would it be ok to use that?

[Kipper4]

Without seeing a schematic it's hard to say.
IIRC the 5v1zener would be used as a part of a biasing network.
So no I don't think the 8v1zener will work.
Welcome.

[highwater]

Kipper's guess is correct - that sets the reference voltage. An 8.1v zener won't work.

A 4.7v zener or a 5.6v zener would be fine though. You might have less headroom that way, or you might not.

For testing, I *think* you could use a 10k resistor there... it might be noisy, might not give a full sweep, and the bias trimpot would need to be re-adjusted for different power supplies and/or as the battery wears down. BUT, if the pedal doesn't work at all, you'd be able to do some debugging while you wait for the zener.

[Clint Eastwood]

If you have some ordinary diodes around, putting 7 in series would give you a resultant diode with a voltage drop of about 5 volts. In theory, in my sick minimalist mind this ought to work, but I have no idea if it will in reality....

[robrhy]

Thanks guys.Bought some 5.1 Zener diodes,all sounds fine.