Nord User Forum

Hi all,
I have a problem with my NL4r, when I put it to sync to external MIDI, it looses sync after a while. To test it I put an arpeggiator with a single note playing on tempo, on a 4 bar measure. At first it looks like it stays in sync, the tempo showing on the led display is right, and changes correctly when I change the clock source. But after a while playing solely the arpeggiator, it starts to drift away from tempo.
I have tried several configurations and only the NL4 drifts away.

Have you had this issue?
I am already using OS version 1.30.

Example config one: Korg N5 -> NL4 : NL4 drifts away (also tested Korg N5 -> Korg Volca Keys, and they stay in sync)
Example config two: Korg KP3+ sends to Novation X-Station which distributes to NL4 and Korg N5: NL4 drifts away from Korg N5 (again, if I substitute NL4 by Korg Volca Keys, everything is fine)

Any thoughts?

Thanks!

Interesting. In my book the NL4 was one of the best slaves to midi clock, because it beat-syncs (and not only tempo-sync like most synths), and it adapts to all tempo changes and measures, and I never had issues there. Make sure that Keysync is off?
But I am not sure if the beat-sync requires more midi data than tempo-sync, I always wonder how the NL4 detects the 1 in a 4/4 measure even if the track is started in the middle of a bar. Is that part of midi beat clock, or song position pointer? Maybe the korg does not send all the relevant data for beat-sync.

*most* midi beat-sync is done using the clock start as the reference for the downbeat. However, MIDI does not, itself, have support for the idea of time signature. SPP (song position pointer) is just an integer of the number of beats since the beginning of the song, and is therefore dependent on the local time signature idea of the receiver to interpret correctly. MTC only sends frame-accurate timing, and is time-based, not beat based. It also lacks the idea of time signature, sending only time-of-day as hours:minutes:seconds:frames.

The primary situation in which MIDI clock goes out of sync is if the receiver IS getting the MMC (MIDI Machine Control = start/stop) commands but is NOT listening to the MIDI beat clock (MIDI "clock" pulses at 24ppqn). If the two machines are set to "close enough" bpm already, they'll start in sync since they both start counting from the same downbeat when the START signal is sent, but they'll drift out of time as they run because they aren't *perfectly* in sync since one is not using the incoming timing from the MIDI clock. Likely your NL4 is listening to the MMC but ignoring the clock sync. I don't have an NL4 so I can't tell you how to check, but maybe someone here with one can help you out with that.

I can confirm that the NL4 receives the beat clock message, because that's the only message being sent by the korgs (message F8 -> Midi Timing Clock). I "listened" to the messages being sent with MIDI-OX on my laptop, and that is the only message being sent, and when I change the tempo on the source, there is no extra messages being sent, only the speed of the F8 messages change, and the NL4 changes the tempo accordingly. (See screenshot in attach).

@Execbat, yes Mst Clk Kbd Sync is Off.

I read somewhere that if, by any chance, a timing clock message is lost, than the midi slave drifts. Which is strange, because it should compensate for it. For instance:

Code: Select all

slave: ----|----|----|----|----|----|----|

           ^    ^    ^    X    ^    ^    ^
           |    |    |         |    |    |
master: ---c----c----c----c----c----c----c
           l    l    l    l    l    l    l
           o    o    o    o    o    o    o
           c    c    c    c    c    c    c
           k    k    k    k    k    k    k
          (1)  (2)  (3)  (4)  (5)  (6)  (7)


If in the above example, message 4 is lost, than the slave should understand it, because all subsequent message continue in sync with the previous tempo. Otherwise, it's understandable that message 5 would be perceived as 4, and tempo would be half during that fraction of time. Overtime, some lost messages with lead to noticeable sync drift.

So what can I do? Better MIDI cables? Better Sync sources??