[RE: VCDO]

[Harry Bissell]

Harry Bissell writes: Gentlemen; Check out Linear Technology App note 14:
Designs for high performance V-F converters (by Jim Williams) How about a 1 Hz
to 1MHZ V-F converter, .06% linearity, 25ppm/Deg C. gain, 50nV/Deg C zero
shift, 0-10V input range. You have to add your "Expo converter Du Jour". Other
designs impressive. Expensive. And probably need a really professional job at
circuit layout to get even close to that performance. But it's probably a
better deal than trying to overdrive and audio VCO. No, I haven't tried it
myself. (Jim Williams is in a league with Bob Pease, thet're just on different
teams...)  Harry

Dave.Peachey at natwest.com wrote:
Romeo,

Well, not a bad little module this one, albeit rather awkward from the
high-speed VCO aspect.  Last I heard (May 1997), Paul Maddox
(space_banana at hotmail.com) was promoting his intended use of Gene Stopp's
ASM-1 VCO (suitably modified) to drive the counter in place of the CEM3340.
You might want to check out the Modulus web-site
(http://www.geocities.com/siliconvalley/park/2707) to see if he ever
finished this off.

I do seem to recollect that Chris Crosskey (chris.crosskey at metrics.co.uk)
was intending to collect EPROM data for this module (amongst others) - you
might want to see if he still has it.

If you're after the PCB foil diagram, I can let you have a *.gif file (66KB)
of this which I've cleaned up and used myself quite successfully.  Let me
know if you're interested and I'll forward a copy.

Cheers for now

Dave Peachey
* Home: 0(44)181-643-8036
*Home: 16 Clowser Close, Sutton, Surrey, SM1 4TP, England
* Work: 0(44)171-480-3334
*Internet: dave.peachey at natwest.com


> ----------
> From: 	8brain at spiritone.com[SMTP:8brain at spiritone.com]
> Sent: 	07 April 1999 06:12
> To: 	synth-diy at mailhost.bpa.nl
> Subject: 	VCDO
> 
> I don't know how many of you are familiar with the digishound VCDO module,
> but I've been thinking, that if someone wants to come up with a good DIY
> kit, this would be a good one.  The module uses a CEM3340 to drive an 2716
> EPROM with digitised waveforms for playback.  There must be some way to
> replace the CEM with a discrete VCO - I suppose it would have to be stable
> at a higher frequency than what normal vcos spin at.
> 
> 
> 


> --------------------------------------------- 
>	Attachment: application/ms-tnef 
>	MIME Type: application/ms-tnef 
> --------------------------------------------- 

____________________________________________________________________
Get your own FREE, personal Netscape WebMail account today at http://webmail.netscape.com.