[sdiy] 9v modules?

[harrybissell]

There is no real reason that you might not run the wasp on 9V with a little
modification of resistor values.

Juergen Haible mentioned that 5V might be about optimum... because you want to
run in the region where the transfer function of the N and P channel devices is
semi-linear.  Highervoltages will have a larger area where one or the other
transistor
tends to turn off completely  (well - JH said something like this)

Power in a cmos inverter based linear circuit is not going to be really low...

There are probably many other filters you could run on 9V.   I'd even suggest
that you (all)
consider using a charge pump IC to make -9V from your battery... you can do just
about ANY
filter with that supply and the efficiency of the conversion can be upwards of
90% in most
cases. Just don't hang anything on the -9V you don't NEED to and you will be
fine.

I'd also consider a Vactrol based filter for 9V operation. You have to eat the
power of 1-2 LEDs
but hey that ain't too bad...

H^) harry

john mahoney wrote:

> Seth,
> When Pat Kammerer was looking for a low voltage filter, Ken Stone wrote,
> "For 5V operation, check out the wasp filter."
>
> Question is, how to derive 5V from 9V without burning a lot of juice in the
> voltage regulator? (That is, I believe that simply running 9V into a 5V
> regulator wastes a lot of power.) There's also the question of how much
> current the filter itself will use, i.e. how long the battery life will be.
> Maybe there is a 9V Wasp filter?
>
> Another alternative: The VCF from Ray Wilson's Sound Lab Mini-Synth
> (www.musicfromouterspace.com) runs on a pair of 9V batteries, by design. You
> could get his PC Board (or not) and build only the parts of the circuit you
> need, if not the whole synth.
>
> It isn't much, but that's all I've got! ;-)
> --
> john
>
> ----- Original Message -----
> From: "denshi" <denshiblocks at yahoo.com>
> >
> > i was curious if anyone has schematics/info on 9v
> > modules such as the groups of modules that Arp made
> > (like the 2600 in seperate enclosures).  i am
> > particularly interesed in making a 9v battery powered
> > resonant low pass filter, to use with handheld
> > instruments.  thanks all!
> >
> > seth