EDP Response time

[a k butler <akbutler@tiscali.co.uk>]

>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 
press,
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 
FCB7)
just that nobody notices it.  :-)

andy butler