Walsh circuit now up

[Paul Maddox]

Michael,

  If the 4066's are running from 5v you can only put in a 5v signal,
it may be better to use discrete FET's, then you dont have a limit
on the coefficient..

   I still think you could subtract 2.5v from the 'WLxx' and feed
this into a VCA with a CV controlling its amplitude. this would
have two BIG advantages;-
   1) no 4066's
   2) you could use a HEX VCA like the 4049 one. You  could sum
these outputs and bingo...

   Adding hard sync to the HSVCO would be pointless, you'd need
to have a sync input on U1 and also all the octal D-type f/f's
this would reset the whole function (Hard sync).

   Another question, what ratio is your HSVCO running at? I mean
if you wanted a 1Khz waveform what speed is the HSVCO running at?
I'd guess 32Khz? (5 stage divider at front end)

   makeing this polyphonic would be hard as tony has used 
clocked Dtypes..... though Im sure it wouldn't be too hard.

   Paul



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-----Original Message-----
From:	WeAreAs1 at aol.com [SMTP:WeAreAs1 at aol.com]
Sent:	Wednesday, September 22, 1999 6:33 AM
To:	oakley at techrepairs.freeserve.co.uk; synth-diy at mailhost.bpa.nl
Subject:	Re:  Walsh circuit now up

Hello Tony,

Very impressive, this Walsh VCO of yours.  I have a question for you:

In the description at your web page, you wrote:

<< The coefficient inputs are voltages that can be varied 
from 0V to +5V. This is the limit imposed by the 4066 
analogue switches. If you used the more expensive DG 
series, you would have more flexibility here, but no money! >>

Why do the 4066's impose a 5 volt limit?  Can't they be powered by up to +15 
volts or +/- 7.5 volts?  Or are you using 74HC4066's?

Also, do you have any ideas about implementing Hard Sync on your high 
frequency triangle oscillator?

Michael Bacich