Polariry Protection diode question in GCB-95

[Quixote]

Hey all! I'm currently working on my take on a Crybaby wah and I had a brief question to ask. In every sample I've seen, there's either no diode at all, or this rather peculiar "ZL9M3" diode. It's a 9.1v Zener, and I can't seem to find where the one I had went. The power supply is identical to the GCB95, so keep that in mind. Can I just replace it with a standard 1N5817 or 4004? I think my board from 1994 might've actually had that 4004. This is odd. I've really just never seen a zener used for polarity protection. Schottkies have a lower voltage drop, no?

[GGBB]

Hey all! I'm currently working on my take on a Crybaby wah and I had a brief question to ask. In every sample I've seen, there's either no diode at all, or this rather peculiar "ZL9M3" diode. It's a 9.1v Zener, and I can't seem to find where the one I had went. The power supply is identical to the GCB95, so keep that in mind. Can I just replace it with a standard 1N5817 or 4004? I think my board from 1994 might've actually had that 4004. This is odd. I've really just never seen a zener used for polarity protection. Schottkies have a lower voltage drop, no?

Zeners are often used for polarity protection because they also provide over-voltage protection. You can replace it with a 400x but you will lose the over-voltage protection.

[Quixote]

Awesome, thanks for the insight! Overvoltage isn't that crucial to me. I don't go sticking random wall outlets into my pedals anyways hahaha.

[antonis]

I doubt if a Zener without current limiting resistor can stay alive in an over-voltage situation..