Need help resolving MIDI Clock Jitter
-
- KVRer
- Topic Starter
- 4 posts since 13 Dec, 2019
Hi,
I am an engineer working on adding MIDI clock synchronization functionality to some effect devices. I am using Logic Pro (10.3.3) to output MIDI clock from my M-Audio Profire610's MIDI Out port.
This in itself is "working", but I notice that the MIDI clock messages are not perfectly consistent. With a BPM of 120, the timing between the clock messages varies between 20.667 and 21.039 milliseconds (ideally they would be 20.833 ms for this BPM, I believe). This in turn causes timing issues with the devices I am developing. Although I'm not entirely sure it's the fault of the clock or my device's firmware
Is this amount of jitter (I believe that's the term) usually acceptable in MIDI clocks?
And if not, would my situation be improved with some combination of Expert Sleepers modules? If so, which ones? If they can help, I'd be one happy customer..
Thank you!
I am an engineer working on adding MIDI clock synchronization functionality to some effect devices. I am using Logic Pro (10.3.3) to output MIDI clock from my M-Audio Profire610's MIDI Out port.
This in itself is "working", but I notice that the MIDI clock messages are not perfectly consistent. With a BPM of 120, the timing between the clock messages varies between 20.667 and 21.039 milliseconds (ideally they would be 20.833 ms for this BPM, I believe). This in turn causes timing issues with the devices I am developing. Although I'm not entirely sure it's the fault of the clock or my device's firmware
Is this amount of jitter (I believe that's the term) usually acceptable in MIDI clocks?
And if not, would my situation be improved with some combination of Expert Sleepers modules? If so, which ones? If they can help, I'd be one happy customer..
Thank you!
MacBookPro9,1 OS:10.11.6
LogicPro 10.3.3
M-Audio Profire610
LogicPro 10.3.3
M-Audio Profire610
-
- KVRian
- 1410 posts since 22 Mar, 2002 from UK
It's certainly common. Some (most?) people would find it acceptable. But others don't, hence products like the Expert Sleepers ones.Is this amount of jitter (I believe that's the term) usually acceptable in MIDI clocks?
Any of the audio-based products (e.g. ESX-8MD, USAMO) should give you a MIDI clock with timing variation of the order of an audio sample (at 48kHz, 21us).
-
- KVRer
- Topic Starter
- 4 posts since 13 Dec, 2019
Great, thank you for the information. I'll look into those.
MacBookPro9,1 OS:10.11.6
LogicPro 10.3.3
M-Audio Profire610
LogicPro 10.3.3
M-Audio Profire610
- KVRAF
- 12355 posts since 7 May, 2006 from Southern California
I used to work in QA at M-Audio... among other things I tested accuracy of MIDI timing. The MIDI I/O on the firewire devices was particularly bad in that regard. The stand alone MIDI interfaces (MIDISport series) weren't as bad but anything that did audio in addition to MIDI had pretty bad jitter and latency.
In my Studio, I use a lot of Expert Sleepers stuff and I can attest to USAMO and ESX-8MD being much more accurate. I have also had good luck with ethernet based MIDI interfaces.
-
- KVRer
- Topic Starter
- 4 posts since 13 Dec, 2019
That's an interesting perspective. I'm looking at those two modules in particular; I'm excited to try them out.justin3am wrote: ↑Fri Dec 13, 2019 9:40 pm I used to work in QA at M-Audio... among other things I tested accuracy of MIDI timing. The MIDI I/O on the firewire devices was particularly bad in that regard. The stand alone MIDI interfaces (MIDISport series) weren't as bad but anything that did audio in addition to MIDI had pretty bad jitter and latency.
In my Studio, I use a lot of Expert Sleepers stuff and I can attest to USAMO and ESX-8MD being much more accurate. I have also had good luck with ethernet based MIDI interfaces.
MacBookPro9,1 OS:10.11.6
LogicPro 10.3.3
M-Audio Profire610
LogicPro 10.3.3
M-Audio Profire610