[sdiy] Dual VCO mixing. / first synth DIY project.

[cacofone]

>Hi.... (what ever your first name really is)

Oops, Joshua


> > Yes, sounds pretty clear :)
>
>Goodie!
>
> > Gonna get started on making some VCO's and go
> > from there. I'll keep the sdiy list updated. I found a good VCO schematic
> > on the Emusic DIY page that has  tri, sq, sine, and I think it also had
> > ramp (might be wrong on the ramp) Can you suggest a VCO schematic that's
> > versatile and not that terribly hard for a beginner, or is the one there
> > recommended? I'd really like to have at least triangle, square, and I
> > really want sine, even though I know, yes, tri/square are easiest, and
> > perhaps I can add the sine in later after I've implemented square. I 
> assume
> > I'd start with square and get that to function, then add the triangle
> > followed by sine.
>
>It is customary to use a sawtooth (more common name than ramp)
>waveform core in VCOs and then waveshape pulse, triangle and sine.

I thought the difference between saw and ramp was the direction of the 
downward slope, i.e.

|\ versus /| however i don't know the difference, I thought /| was saw 
(what's printed on the tb-303, etc), but since I read from left to right, 
it makes more sense to me that would be ramp.... but consider the source, 
it can see why it would be be different.

>However, the triangle (and thus sine) does not get very well when
>cooking it from sawtooth. However, cooking sawtooth out of triangle
>and square should be fine.
>
> > Any advice is greatly appreciated.
>
>Check out the ASM-1 synth among others. This is a pretty good standard
>oscillator.

Definitely one of that I've looked at.

> > I also assume that these can be compounded using the opamps to add more
> > VCO's in the future? I've got a fairly large case that I'm intending to
> > fill (used to be a tape deck cabinet), and this is my first DIY synth 
> project.
> >
> > I read somewhere to do the power supply first, though I've seen pre-made
> > ones that are cheap, supposedly reliably, and wouldn't "waste" time. Any
> > thoughts?
>
>Either way, get a power supply early, you want to have it around to
>test out the VCOs as you get them done.
>
> > Can you or someone else elaborate a little more on what you mean by
> > inverted? I assume the polarity (-/+) but if I wanted to re-invert it, how
> > would I do so?
>
>Toss it through a similar setup but with only one input.
>
>That is, if you *really* require the right polarity.
>
>Cheers,
>Magnus


Thanks again for even more information. I'm excited and anxious to get 
started, but I want to take it slow and make sure I'm doing everything 
right in advance.

Joshua


Pulse 8 / nKode / cacofone [aim:goodtimetribe]
http://www.goodtimetribe.com - Good Time Tribe 
http://www.mp3.com/stations/d-r-e-a-m DREAM Radio Station
http://www.mp3.com/pulse8 http://www.mp3.com/nkode http://www.mp3.com/cacofone