[sdiy] F->V converter

[harrybissell]

Hmmmm.... is this practical...

Yes... for a theremin.  The output of the theremin is a continuous
frequency.... and you can't move your hand very fast anyway.

Try this tachometer circuit on a guitar, and you have entered
'hopelessville'...

Guitar low notes go down to 80Hz... so if you make the ripple low enough

to track... the response time will be in the hundreds of milliseconds.

The other good thing about a theremin is that is is (lets call it)
monotonic...
you can't get from point A to point C except in continuous motion
through
point B.... so the tracking nature of the tachometer is not as bad
here...

The Bob Moog ramp and hold design (Voltage output for Etherewave
Theremin
once a board I did called the PV-1)... can get an accurate, ripple-less
CV out
within 2 cycles of the fundamental pitch. For guitar, this is still at
least 24mS...
dead slow.

I'm not sure there are any good 'audio' uses for F/V converter chips...
except possibly encoding and decoding control voltage tracks on a tape
recorder... a use
now largely obsoleted by modern computers...

(if anybody is really really interested in V/F or F/V chips and wants to
buy a sh!tpile
of them... the company I work for is about to get rid of NOS units.  I
declined to
get these for myself (because of lcak of audio uses).  Contact me
offlist and I'll
convey your offer to buy the whole lot of them (don't bother with 'I
need three'...
its all or nothing).

H^) harry

PRCamann at aol.com wrote:

> Try here for a practical use of the 2917 for audio:
>
> http://www.dogstar.dantimax.dk/theremin/disptech.htm
>
> Paul Camann