[sdiy] controlling VCO with guitar

[Paul Perry]

It's not trivial to get +-15v with charge pumps - check the input voltage 
ratings on the cheap pumps.
By the time you have done all that, you might as well do what i do:

Bite the bullet and get a 14V AC (not DC) plugpack.
One wire to ground, the other to a pair of half wave rectifiers with a 
1000uF cap for rough + and - supply,
the 14V AC will give you enough headroom for a +15 and a -15 regulator.
Cheap & simple. Very robust (especially if you take the advice from the 
National Semiconductor app notes)

paul perry Melbourne Australia

----- Original Message ----- 
From: "megaohm" > Dan,
> Cool demo.
> Was checking out your site and noticed the +/-15V rails from a 9V wall 
> wart?
> How do you do that? I've seen some charge-pump circuits on the geofx site.
> Similar?
> I'm curious because I have some external box controllers for the
> modular but scratching my head when addressing the PSU. I've been
> tapping my modular's distro board for the +/-15V but that doesn't do
> me much good when I want to go elsewhere and use these on other
> synths.