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

[Seb Carr]

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