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Re: EDP Response time

I remember Kim or Matthias saying that responding to EFC buttons took
twice as long as MIDI--something to do with debouncing.


On 12/9/05, a k butler <akbutler@tiscali.co.uk> wrote:
> >Again, my understanding is that the EDP was designed so that the lapse
> >between command and execution is constant, and I believe that constant
> >is 1.5ms.  A constant 1.5ms seems to be plenty accurate enough for
> >musicians needs in this context (looping).
> Matthias once told me that this 1ms is the time for one "loop" of the
> edp software.
> ( or it may have been 1,5ms)
> So within that time the software checks whether there's been a button 
> and then processes 1ms of audio. ( if I understand correctly)
> So max latency is where the button press is just after the check,
> and min latency is when the button press is just before the check.
> So latency can't be constant.
> It must have a variation ( = jitter) of 1ms.
> Actually, using stereo linked EDPs, there seems to be more
> than that, there's clearly a time difference between the 2
> edps.
> Particularly when using NextLoop there's often a 4ms delay
> between loops on the 2 edps, which produces a pronounced Haas
> effect ( audio appears to be panned).
> This seems to vary at random on each use of Nextloop.
> As slave EDP is controlled by the midi output of the master, then
> it would seem that the edp has a jitter of 4ms.
> (or maybe 2ms per edp)
> presumably that jitter still happens when a single edp is used,
> (and as far as I know, it shouldn't be any different for Midi control or 
> just that nobody notices it.  :-)
> andy butler