[sdiy] Control volt into computer over soundcard?

[Magnus Danielson]

From: Iain Duncan <iainduncan at telus.net>
Subject: Re: [sdiy] Control volt into computer over soundcard?
Date: Mon, 01 May 2006 21:59:39 -0700
Message-ID: <4456E73B.1020708 at telus.net>

> >>I was thinking, perhaps an amplitude modulate pulse
> >>wave at the nyquist
> >>would be good because on the computer end, then
> >>every second sample
> >>would be the correct data ( either 0 or peak amp )
> >>making riding the
> >>signal simple ( and need a very small window ). I
> >>have no idea how
> >>practical this would be to generate in electronic
> >>terms though, any
> >>suggestions?
> > 
> > 
> > That sounds like a really tough way to do it...
> > How would you guarantee that you were right at the
> > limit and would stay there without drift.

Um yes, you really would have to be synchronous to the sampler... sounds like
a hell of a way of doing it.

> Thanks Harry, I'm sure you just saves me lots of frustration. That's why
> I'm here!

That's the spritit! :O)

> > There were some previous threads on using FM methods
> > to record CVs with a sound card... check the archives
> > for some really good (and really bad) ideas
> 
> So, how do I know which are which? ;)

That's why we call it "The creative patch storage method" :P

You have to keep them sufficiently separated in frequency and naturally keep
track of which goes into which channel, just as I expect you to keep track of
which synth goes into what track when you record. You can usually figure out
after the fact which was which for both types of signals, but it is a hell
easier to keep track of things when you do it.

Another way would be to make a plain A/D and D/A card, but that may be more
software work than you may feel up to. Piggybacking on the audiocard would
work, but editing it would certainly require some dedicated software. Hohoum!

Cheers,
Magnus