22 Mar
2010
22 Mar
'10
8:13 p.m.
On Mon, Mar 22, 2010 at 11:42:58PM +0100, Nick Copeland wrote:
I think there is a bit of confusion on this thread
(and said so in one of my replies)
regarding MIDI vs CV. I still see them as separate where MIDI defines parameters
of a component such as oscillator tuning, waveform, transpose, and MIDI handles
them perfectly. Then there are modulators which are signals that change the osc
frequency and can have many sources (LFO, Env, S&H). I feel that native rate,
floating point CV is best for these. The oscillator is just an example, gain, filter
cutoff, etc, are others.
Perhaps it is just me that is confused but I still see a dichotomy where on one
side there are parameters that can be automated/quantised and on the other side
there is modulation that needs to be exact and smooth. This is the difference
between CV and control automation but the thread seems to me to be discussing
both at the same time.
I think you're absolutely right about the confusion, and
it's not just you being confused.
For me, MIDI is just 1) a way to encode data, and 2) to
get it from A to B. It has some severe limitations, one
of them being that it has no credible semantics for
continuous control. The only way is to send a stream of
parameter updates, and then it all depends on the receiver
if this results in a 'staircase' or a smooth trajectory.
The advantage of a defined rate (audio or sub-audio) 'CV'
style data type is that at least that interpretation is
defined - it is bandlimited by its sample rate and that
more or less imposes the only valid way to interpret it.
Another limitation of MIDI is its handling of context,
the only way to do this is by using the channel number.
There is no way to refer to anything higher level, to
say e.g. this is a control message for note #12345 that
started some time ago.
As far a I can see, any application dealing with control
data should offer MIDI only as one possible I/O format,
but certainly not use it internally, or be based on it.
Ciao,
--
FA
O tu, che porte, correndo si ?
E guerra e morte !