Doepfer

Hi ele

> i'd want to make all sorts of sequences of numbers and waveforms and 
> send them out of the computer as smooth cv's.
> this is what the dac resolution is all about, right? a 12 bit dac won't 
> be able to generate a smooth slow increase from one voltage to another, 
> or replace a real sine wave lfo?
I think you hang on a rumor, that isn't really true for everyone. But it 
depends on what kind of Sound you want to do. Example:

First thing: there is no real sine LFO in modular systems (sorry, I do 
not know any), because they would require a LC-based generator. Every 
digitally created LFO will be a better sine but an analogue created one.

Second thing: The usablilty of a modulation source depends mostly on the 
usage of the modulation. Example:
You have a rythm orientated music and want to do a modulation of a VCO 
over one octave by an Soft LFO within pattern measures, lets say with a 
"frequency" of 2 bars at a tempo of 132, then the stepping of an 8bit 
modulation (256 steps!) won't be really audible. So the same soft-LFO 
resolved with 12Bit (=4096 steps) will be satisfying also for a LFO 
duration of 16 bars.
If you do the same modulation to a VCO without rythm instruments in the 
background. The stepping of 8 Bit with a 2 bar duration will be audible 
at the VCO. You will require 12Bits.

But now: If the modulation destination is not the VCO but the VCF cutoff 
frequency, then the same modulation will be satisfying completely. If 
the destination is a VCA and the audio signal is a sine, you will 
definitley hear so called zipper noises. If the audio signal in the VCA 
is a saw, you won't realize any digital modulation noise.

So you see: whether a digitally created modulation source is good or 
not, depends completely on the usage of this modulation. I am sure, we 
will find examples, where a 16-Bit Modulation won't be good enough! In 
these cases we have to use slewlimiters - thats what they are for.


> am i correct that the mcv4, for example, won't let you send any kind of 
> controller message out of any or all outputs? why these limitations of 
> only certain kinds of midi messages on certain channels?
The limitation is mostly based on the userinterface. Technically it 
would not be difficult on the D/A side, but it requires a very expensive 
userinterface (Display, alphadial,...) to handle this.

So the concept for a low-cost interface must be a fix one.

Florian