[sdiy] Pitched Noise/VCO Bank Schematic Posted

[Scott Stites]

Hi Theo,

> Interesting, a 606 cymbal noise circuit with added RM + CV.
> (give credit where due ;^p )

Ah - I didn't know that!  I do know that Ken Stone uses a similar oscillator
bank arrangement in the Cynare and - wow, taking a look at it again, he uses
EXORs too!  I hadn't consciously realized that until now (though I've surely
looked at the schematic before now).   I've victimized two respected
designers in one schematic!

I wanted to get Tom Henry's permission mainly because I took the bank
schematic straight from his book, and used the same initial frequencies he
did.

> Think I did something generating similar sounds in ?DSP? (on Atari ST, not
> real-time..)
> First generating narrow noise band samples
> (recursive additive method using a sine table,
> calculate freq= center freq + tri-lfo on each sine period start,
> write output so a cyclic sample buffer,
> run longer = higher noise density).
> Next use those noise band samples as the "partials" for normal additive
> synthesis.
> My results where less "lively" than yours though and needed some chorus or
> phasing to live-, err make that scare-up.

I imagine being DSP based makes it much more versatile - I wish I had an
inkling of understanding for programming DSP's.

Cheers,
Scott

> ----- Original Message -----
> From: Scott Stites <scottnoanh at peoplepc.com>
> To: synth diy <synth-diy at dropmix.xs4all.nl>
> Sent: Wednesday, April 14, 2004 6:12 AM
> Subject: [sdiy] Pitched Noise/VCO Bank Schematic Posted
>
>
> > Hi List,
> >
> > As promised, I've posted the schematic of the 40106/4070 VCO
Bank/Pitched
> > noise circuit *as it appears on my breadboard* - let me qualify that -
it
> > was a case of limited breadboard real estate combined with a "wonder
what
> it
> > would sound like if I did this" mentality, and is not how I would
> implement
> > it for a module (at least the CV portion).  So, no guffaws from the
> > bleachers, especially when you see how I decreased the sensitivity of
the
> CV
> > in.
> >
> > There are several obvious ways it could be improved (10M resistors in
> > parallel with the VTL5C2 resistors would be a nice start - or using
series
> > resistance instead of parallel).  Also if one were to - Bissell!  Turn
> > around and sit up straight, young man!
> >
> > As I was saying, if one were to put in pots to tune the various stages
or
> > use some other CV control scheme, it may be a neat way of using it as a
> > 'drone' bank as was discussed earlier on this list.  I'd be interested
to
> > know if there were some economical/expedient way to smooth out the
square
> > waves.  In that case, one could plunk in one of those fancy quad four
> > quadrant multiplier packages in for some fairly cool effects.  It's
really
> > just a - I saw that, Mahoney!  I've got my eye on you...
> >
> > Uh, I think it would be a nice launching point for various applications.
> >
> > I did get the oscillator bank design from Tom Henry's 'Noise Generator
> > Cookbook', and he did give me permission to put it up in this schematic,
> > though he hasn't really seen it yet.....he may very well see it and say
> > "Pull that @#$!! thing off the net NOW!  Oh my God, I'm ruined."   =-D
> >
> > It's at the top of my Birth of a Synth page here:
> >
> > http://mypeoplepc.com/members/scottnoanh/slsdiy/id18.html
> >
> > Cheers,
> > Scott
> >
> >
>