Going simple since the missus won't let me devote time to the kind of projects that correspond to my ambitions :icon_lol: :icon_lol: :icon_lol:
so I decided to build meself a SHO, and on vero, too :o I found the board completely by accident a while ago, I don't even like this build medium, but since it's such a simple circuit, I decided to give it a try.
So I have just a couple of quick questions about it and I'ma be on my way:
1. I see a 9V1 zener in some schematics. Would all hell break loose if I omitted it, and then power the circuit from 12V or so? (basically 9V@300ma unregulated)
2. A 10k lin pot in parallel with a 10k resistor makes a 5k log pot. Amirite?
1. Use the zener, it protects the Mosfet from overvoltage and really shouldn't be omitted.
2. Sort of. I think you really want a 5k lin or 5k rev. log pot, but I'm thinking the parallel resistor might get you the Rev. Log taper you want in this case.
Definitely use the zener between Drain and Source, you risk frying your mosfet without it.
A nice read on pots (and their tapers) over at Geofex - The Secret Life of Pots
The section on changing a pot's taper to reverse log is at the bottom.
http://www.geofex.com/article_folders/potsecrets/potscret.htm (http://www.geofex.com/article_folders/potsecrets/potscret.htm)
There is an early SHO schematic that uses a couple 4148 diodes in place of the zener to protect the mosfet. However you do it, protect the mosfet.
http://analogguru.an.ohost.de/193/schematics/Zvex_SHO.gif
dave
edit:fixed spelling mess
^ That's it! :) Thanks for pointing it out, this is what I'm gonna do.
FWIW an LED would probably work too.