[sdiy] Random Tone Generator redux

Wed Mar 25 17:51:21 CET 2009

That's another good idea, having the board in and of itself have a degree of modularity. There's potential to cook the random tone gen, some variation on that, or a bend matrix... lot's of possibilities.

You'll get more harmonic content with sawtooth (teeth? heh) waves. The 4046/4024 waveshaper will do that for you, though the standard square out could be put into an external VCO's sync, kinda expanding your palette.

This is based off an MIT design, right? I can't find the link myself now, but I recall there were two samples on the page for it...

_Kyle

--- On Wed, 3/25/09, Ian Smith <taciturn_unquiet at hotmail.com> wrote:

> From: Ian Smith <taciturn_unquiet at hotmail.com>
> Subject: RE: [sdiy] Random Tone Generator redux
> To: "synth diy" <synth-diy at dropmix.xs4all.nl>
> Date: Wednesday, March 25, 2009, 7:25 AM
> 
> Hey all,
> 
> I think to keep feature creep down to whatever people feel
> comfortable with I'll set up the board so you can include or
> omit ins and outs as you prefer. I'm kinda wavering on the
> suboscillator on the output because of the low range
> switch.
> 
> I'm thinking about putting the external clocks after
> Schmitts B and C using switched jacks normalized for the
> internal clocks so you disconnect the internal clocks by
> plugging into the jack. the question is, would anything work
> to clock the 4051s or do I need to put something in to
> convert an external signal to a 0/+5V square wave?
> 
> Definitely using the transistor VCA, again with either an
> internal modulation using another Schmitt trigger or with an
> external input.
> 
> Outs from the clocks (schmitts B and C) with possible
> switches to allow clock through from the external clock
> jacks.
> 
> I feel obliged to have an output level control because most
> existing modules don't have input level controls, except
> maybe some filters that have built in mixers (MFOS). This
> brings up another qiestion of a module of multiples that
> have attenuators before every out....
> 
> If this was a stand alone unit, I would be tempted to add a
> filter or two, but as this is intended for a modular unit,
> no filter.
> 
> How do people feel about it outputting two or three
> different waveforms?
> 
> As for sound... I have to admit haven't breadboarded this
> incarnation of the thing yet, but the last one I did which
> had 4020s instead of 4024s was rather trilly between a few
> of the notes depending on how the clocks were set. I'm going
> to try to get this version breadboarded sometime next week
> because this week is a little hectic.
> 
> -Ian
> 
> > Date: Tue, 24 Mar 2009 22:16:43 -0700
> > From: lightburnx at yahoo.com
> > Subject: RE: [sdiy] Random Tone Generator redux
> > To: synth-diy at dropmix.xs4all.nl
> > 
> > 
> > I've been talking to Ian off list, and thus far we
> got:
> > 
> > -4024 as a suboscillator on the output; individual
> outs and/or summed staircase out
> > -The bigger divisions off the 4024 can work as CV or
> gates
> > -Spare Schmitts modulating existing Schmitts A, B, or
> C with Vactrols
> > -MFOS WSG tricks, like a transistor VCA
> > -Multiple, buffered taps out from within the circuit,
> pending they give dramatically different enough outputs
> > -External clock/line in (again, to Schmitts A, B, or
> C), not unlike this guitar FX design here:
> > http://www.geocities.com/tpe123/folkurban/fuzz/pwm.gif
> > 
> > As for a dirt simple filter, maybe a rotary switch
> with various cap values on the output. I reckon it'd keep
> feature creep down (not that it hasn't been chugging along
> already) to let an external filter do the work.
> > 
> > And by way of waveshaping, there's some interesting
> stuff to be had here:
> > 
> > http://www.geocities.com/picsynth/sawtooth.jpg
> > 
> > Main site: http://www.geocities.com/picsynth/
> > 
> > 
> > Indeed, I'm curious how the beast sounds as is too!
> > 
> > 
> > _Kyle
> > 
> > --- On Tue, 3/24/09, Colin Hinz  wrote:
> > 
> >> From: Colin Hinz 
> >> Subject: RE: [sdiy] Random Tone Generator redux
> >> To: "synth diy" 
> >> Date: Tuesday, March 24, 2009, 9:26 PM
> >> On Mon, 23 Mar 2009, Ian Smith
> >> wrote:
> >> 
> >>>
> >>> Hi all,
> >>>
> >>> Here's a link to a schematic that I drew up
> for that
> >> pseudo-random tone
> >>> generator.
> >>>
> >>> http://www.sdiy.org/modius13/randtonereduxschem.pdf
> >> 
> >> Interesting! How does it sound?
> >> 
> >>> If there's anything anyone can think of to add
> to it
> >> feature-wise
> >>> that would make it a decent module, I'm open
> to
> >> suggestions.
> >>> (trigger outputs, different waveforms,
> multiple voices
> >> in one
> >>> package, etc.)
> >> 
> >> Output level control, with perhaps some dumb
> simple
> >> waveshaping or
> >> filtering?
> >> 
> >> - Colin
> >> 
> >> _______________________________________________
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> >> Synth-diy at dropmix.xs4all.nl
> >> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> >> 
> > 
> > 
> >       
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