Fast VCOs for wavetable

[Arthur Harrison]

My first guess is that it would be far simpler to use an 
adequately fast VCO to begin with.  As someone 
pointed out, there are several Jim Williams' circuits 
(Linear Technology Corp.) that will work, and I would also
look at Analog Device's fast VCO ICs.
Perhaps the AD650, a 1MHz full-scale part with 0.1% 
non-linearity, would work.
(See:   http://www.analog.com/pdf/ad650.pdf)

-Art

-----Original Message-----
From: Drew Hutchison <dhutch at kadets.d20.co.edu>
To: synth-diy at mailhost.bpa.nl <synth-diy at mailhost.bpa.nl>
Date: Saturday, November 21, 1998 8:22 PM
Subject: Fast VCOs for wavetable


>Seems there has been a lot of discussion on this lately.  Anyway, here's
>my input:  It has been fairly well agreed that no VCO we know of can
>handle running at 32-64 times the speed we normally use them with enough
>stability to reference a table.  Would it be possible to run a VCO
>(Stopp's?) at a normal speed and send that through a multiplier of some
>form?  I know there are many circuits out which do this at MUCH higher
>frequencies than audio, and they seem pretty stable.  It seems like a
>phase locked loop might do it.  Any thoughts?
>
>