26 Jul
2015
26 Jul
'15
2:26 p.m.
On Sunday 26 July 2015 05:01:46 Jeremy Jongepier wrote:
On 07/26/2015 10:34 AM, Ralf Mardorf wrote:
The jitter is, for some folks minor enough they do not notice it. It is
however, there. Those of us doing CNC machinery control are very aware
of it, primarily because when moving steppers at a decent rpm, excessive
jitter costs us considerable in motion speed. Stepper torque about 3 or
4 hundred rpm depends hugely on having the step signals at a steady
rate. A 10% jitter, at a 10 kilohertz step rate costs us 50% of the
motors power because the delayed pulse is equ to a stop of 10
milliseconds, & when the USB gets around to sending the next pulse, the
rotor speed is below the desired speed, and the motor then see's a large
acceleration it cannot do in a single full step, so it stalls instead.
Stalled motor = wrecked part & possibly broken cutting tooling at a
minimum cost in the 10 dollar area but can go up rapidly for some of the
fancier tooling. Not to mention the time & material waste when you have
to start on a new part from scratch.
If you think your music you write sounds ok now, go play it on a system
that does NOT use USB in the midi chain. If you have any sense of
rythm, I think the difference WILL be quite audible to your own ears.
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>
At least don't use USB for MIDI, you might
not
be able to notice the MIDI jitter, since this also is related to
what you want to do, but USB MIDI does not provide "best quality".
In the meanwhile the whole planet is using USB for MIDI. Please
explain what is wrong with it, if possible with test results or
something else that confirms your assumption. I've never experienced
any jitter issues, not even with external MIDI gear.
Jeremy