AW: EDS wasp schematics?

[steve.ridley at bbc.co.uk]

Perhaps I didn't explain myself very well.  The idea was to retain the 
two 
oscillators (555s) but use the 8052 to replace the divider section.
Hence the 8052 not the 8051 - gives an extra counter/timer - one for each
DCO and one to set the baud rate for the serial port midi.  Still retains 
the
essential free-running fatness - just replace CMOS control & divide with
a microcontroller.  The 4046 PLLs would come after the 8052, so the glide
would add to the general free-for-all.

I think we're getting into the questionable issue of what defines a DCO.
At the more analogue end, we have lots of early 1980s polysynth using
the SSM2031, 555 or whatever as a master oscillator for each oscillator 
per
voice.  For example, the Siel DK600 uses two SSM2031, one for all the 
DCO1s
and one for all the DCO2s, with dividers producing the octaves and 
semitones
for each voice.  This still leaves most of the free-runningness of an 
analogue
if you play it monophonically (sp?), allows for analogue pitchbend and 
modulation and sounds good except in unison.  Seems like a good 
compromise and  ties in well with the name _Digitally_Controlled_ 
oscillator.
I think the same technique was used in a few monosynths - the Siel Mono
and the Jen SX1000 did this using the SGS M110 to do the dividing.

The next stage is to derive both DCO1 and DCO2 off the same clock.
This was used in the Korg Poly 61 (I sold mine) and (I think) in the 
Matrix 1000
and Cheetah MS6.  Detune digitally to give two VCOs.  Nearly as 
interesting as
watching paint dry...

I fear this could turn into a heated debate.....     ;-)


Steve Ridley