These awful jumps (in the size of dozens of samples) that happened every 10-20 seconds or so in earlier tests (which I only performed in scsynth though) seem to have completely disappeared.Wow, the NTP client on OSX 10.10 must have been quite bad then... Usually, NTP clients gradually speed up / slow down the clock until it matches the obtained NTP time. Jumps should only happen as a last resort, e.g. in case of a leap second.
Since your problem disappeared in macOS 10.15, they have probably improved the NTP client implementation in the meantime.
Christof
Am 23.05.2021 um 04:18 schrieb jamshark70@xxxxxxxxx: On Sat, May 22, 2021 at 11:33 PM <daniel-mayer@xxxxxxxx> wrote:On the flip side, compared to my original testing (https://scsynth.org/t/imperfection-of-language-based-timing/350), the bespoken issue seems to have dramatically improved. Now I have tested on OS 10.15.7 with 3.11.2 – no idea what caused the change. These awful jumps (in the size of dozens of samples) that happened every 10-20 seconds or so in earlier tests (which I only performed in scsynth though) seem to have completely disappeared. ...I wonder if NTP has anything to do with this in Mac?BINGO !!! That’s an amazing catch, James, thanks ! It solves an eternal issue ! On my old desktop (OS 10.10.5) I just disabled ”Set date and time automatically” in my system preferences, restarted the computer (not sure if necessary), ran the test again and got, as on OS 10.15.7, maximum deviations of one sample with scsynth. I’m unable to launch supernova with this SC version (3.9.3), but probably the results would be sample-accurate like with the tests on the other machine (at least with the bespoken example). @shiihs got the same big deviations when performing my tests on Linux (https://scsynth.org/t/imperfection-of-language-based-timing/350/4), so disabling NTP is probably the way to go. I’m very happy about this finding because it enables nice synthesis options with patterns being unreliable so far. E.g., a pulsar stream like that didn’t sound smoothly. With new settings and max deviations of one sample this is perfectly ok now (at least for my ears). There might be cases where the supernova variant could turn out to be better, I’d have to do further tests. // ATTENTION: with NTP you get nasty and sometimes loud bumps every some seconds ( SynthDef(\sinePerc, { |out, freq = 400, att = 0.005, rel = 0.05, amp = 0.1| OffsetOut.ar(out, EnvGen.ar(Env.perc(att, rel), doneAction: 2) * SinOsc.ar(freq, 0, amp) ! 2) }).add; ) ( x = Pbind( \instrument, \sinePerc, \freq, 500, \dur, 0.005, \att, 0.002, \rel, 0.002 ).play ) x.stop Would be interesting to check the circumstances on Windows. Greetings Daniel ----------------------------- http://daniel-mayer.at ----------------------------- _______________________________________________ sc-users mailing list info (subscription, etc.): http://www.birmingham.ac.uk/facilities/ea-studios/research/supercollider/mailinglist.aspx archive: https://listarc.bham.ac.uk/marchives/sc-users/ search: https://listarc.bham.ac.uk/lists/sc-users/search/