On Wednesday 16 April 2014 08:44:15 david did opine: > On 04/15/2014 03:17 AM, Len Ovens wrote: > > On Tue, 15 Apr 2014, James Mckernon wrote: > >> On Mon, Apr 14, 2014 at 2:06 AM, Len Ovens <len@xxxxxxxxxxxxx> wrote: > >> I would realy like to stay away from having to use a USB or FW > >> audio IF. In fact I would like to be able to continue to use my > >> delta 66 for as long as I can before I spend more money :) The > >> > >> Thanks for the useful info in your post. Just to be clear on this > >> part: are > >> you saying you don't want to switch to USB/FW solely because you want > >> to keep using your delta 66, or because you have some definite > >> preference for > >> PCIe over USB/FW devices? If the latter, I wonder why? > > > > USB in audio is limited. Getting clear USB ports interrupt wise is not > > easy. Audio can not be on a hub or share it's usb with anything else, > > but many new MB have no mouse or kb port so the USB is already being > > used for that much. The real reason though, is latency. With the pci > > the latency can be 1/4 what it can be in USB or FW. That is the > > lowest seeting jack for USB or FW is 64/2, but I can run the d66 at > > 16/2 with no problem on a well tuned system. This does make a > > difference for live work. I know that 64/2 seems like very good > > latency (it is) but remember that the card then adds another ms in > > each direction as well as the stage distances on top of that. That is > > the time it takes the sound to reach my ear after going through the > > computer as a processor and then through the air to my ear. Maybe > > that is still not worth worrying about... but even with 30 feet of > > cord and no digital delay, I can hear the delay from my playing to > > the sound reaching my ear. > > Interesting. What is the difference between speed of sound in air and > the speed of electricity through a cable? Sound is nominally 720 miles per hour. Rather leisurely IOW. A perfect cable is C speed, 258 times faster. But cable (coaxial) actually range in speeds between 66% of C for home usable cables, to around 98% of C for 9" diameter high power broadcast stuff, C being 186,272 miles per second in a vacuum. Thats 298,035.2 kilometers per second for the metric folks here. > I think the lowest I've had my UCA-202 (USB 1.1) card work at was around > ~3msec latency (on a USB2 port) with a Debian RT kernel just fooling > around (no other RT optimizations on this 2.4GHz i7 laptop). I've had > Yoshimi problems when latency gets too low on my stock kernel. And when > I first tried Zyn, it had problems at much higher latencies than Yoshimi > did at the time. > > But I haven't done much music stuff with my new laptop. Cheers, Gene -- "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> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
