I just built a Maestro FZ-1 FUZZ TONE to a friend and he didn't wan't to use 2x 1,5V AA batteries (which I have in my original).
At first I tried to use a LM350T voltage regulator to get +9V to +3V which I ran into the 7660S but this lover voltage caused the oscillator whine to drop down to audible levels.
So after some trial and error I got something together that works for me. It's a 7660S inverter giving -9V to a LM337T negative voltage inverter which outputs -3V.
So here's a quick vero layout that I just built so it's "verified". Do take it with a grain of salt as I'm more of a trial and error guy when it comes to electronics, don't really understand why things work when they do
I'm open to suggestions if you have a better or more elegant solution!
With some adjustment of the resistors R1 and R2 you should probably get down to -1.5 V.
And credit where credit's due, I copied the 7660S inverter section directly from IvIarks vero at tagboardeffects.blogspot.fi
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