[sdiy] First DIY synth (555 osc.'s)

[perpetual]

it's a tad different.  i sketched up a schematic last night, i'll get
that on the site today.

best,
alex

Seb Carr wrote:
> 
> I looked at the link to geocities, and the sample of the 555 osc is very
> cool, but is there a schematic for it, or is it just the osc from the
> datasheet?
> 
> Seb Carr
> 
> ----------
> >From: perpetual <perpetual at uswest.net>
> >To: synth-diy <synth-diy at node12b53.a2000.nl>
> >Subject: Re: [sdiy] First DIY synth (555 osc.'s)
> >Date: Mon, May 7, 2001, 5:37 pm
> >
> 
> >
> >> > I wanted to build a bear bones system for more of a learning experience
> then
> >> > anything else.  I planed to build the VCO and ADSR from simple circuts I
> >> > found based around 555 timer chips and I was going to use CEM chips for any
> >> > or all of the VCA,VCF and LFO (if I included one).
> >>
> >> Huh? VCO with 555, but LFO with CEM chip?
> >>
> >> > I would use batterys in lue of a powersupply.
> >>
> >> If you do so, use a VCO that is unsensitive to power supply voltage. Or
> >> you'll have to re-tune all the time when the battery goes weak...
> >
> > so i was playing with a 555 oscillator last week.  more info here:
> > www.geocities.com/aurelialuz/shadow.htm
> >
> > what i've found is that all this talk about instability is true.  this
> > thing is really temperature sensitive.  and we're not talking like a
> > couple cents over an hour, i'm talking like octave flucuations from
> > minute to minute.  this thing is powered off a battery too, so i've got
> > both demons of instability working against me.  if i was really
> > interested in creating some sort of stable oscillator, i'd look
> > elsewhere.
> >
> > but lucky for me, i care not a whim for stability.  and what's really
> > cool about this thing is when you feed a wave output from another
> > oscillator into the CV input.  it becomes something like a sub-osc., but
> > instead of creating a low note, it gives all these weird overtones, sort
> > of like an "effects" oscillator.
> >
> > also, i've always read that 555's put out a pretty weak tone, but i put
> > a pretty big poly cap in it (.18uf) and i was suprised how thick it
> > sounds.  so if you go the 555 route, the bigger the cap the better.
> >
> > best,
> > alex