i’m a I long-time Cubase user and I’m banging my head against a wall over some MIDI Clock issues with my current rig. I’m running Cubase 7.5.20 64-bit on a modern Windows 7 64-bit PC with an Edirol UM-880 MIDI adapter. I’ve always used Cubase’s internal clock to sync external devices (synths, effects, etc.) but I started running into issues when I tried to sync a DSI Prophet 12 Module to MIDI Clock.
Whether slaving the P12 to MIDI clock over its USB MIDI connection or DIN MIDI with my Edirol, I can’t get the P12’s delay lines to sync with any consistency. When Cubase is set to 120BPM and the P12 is slaved, the P12’s tempo display vacillates +/-3BPM, and when the perceived tempo changes the delays react by warping and warbling so oddly that the delays effectively can’t be used. A few more interesting observations:
- I have Cubase set to pass MIDI clock when stopped, and the drift is mild when the P12 isn’t receiving any direct MIDI data (i.e. note ons/offs); it sits at the prescribed MIDI clock tempo with brief, intermittent deviations. But when I play notes or the DAW plays back notes, the P12’s clock deviates more rapidly and substantially. You can watch the P12’s tempo indicator change as a direct result of notes being played. The more notes and the faster played, the faster the tempo moves between values.
- The clock issues almost disappear at lower tempos 80 and below, and they are much worse at higher tempos (deviations of +/-6BPM have been observed above 200BPM).
- Oddly, the P12’s arpeggiator seems to maintain sync even when the delays freak out. I have a long-running ticket open with DSI and they say the MIDI clock for the arp and delays are derived in 2 different ways. They also assure me that they are certain that the issue is coming from my DAW/Cubase, which brings me to…
- Other devices show mild deviations in MIDI tempo, but nowhere near what I experience on the P12. I have a couple Eventide pedals, for example that show occasional tempo deviations of +/-1BPM at most, but they generally sound tight at 120BPM. Similarly, my Bass Station seems to sync up with no problem at 120BPM and it, too only shows occasional and minor tempo deviations +/-1BPM at most.
- I tried migrating the Edirol’s USB connection to a different cluster of USB ports on the PC and I tried USB 3.0 and 2.0 ports just for kicks – no change.
- I also disabled MIDI Clock output to every device but the P12 – no change.
- I hooked up the DIN MIDI input on the P12 from the thru port on an Eventide pedal that receives MIDI clock from Cubase via the Edirol. Switching back and forth between USB MIDI and DIN MIDI as clock sources, I believe the clocking is perhaps somewhat more stable over the DIN MIDI input – there’s less frequent deviation and milder swings in tempo (mostly +1/-2) – but still not usable for long delays because of how oddly the delay output warbles and warps as it tries to adjust to the drift on the fly. Maybe the Eventide is “stabilizing” the issue for the P12 to some extent?
DSI swears up and down that what I’m seeing proves that I’m having MIDI Clock issues, though I’m still somewhat skeptical given that other devices seem to sync to MIDI Clock with repeated success. The fact that the P12’s delay sync struggles whether using the Edirol connection or its own USB MIDI connection suggests that the Edirol is not the culprit, so now I’m looking at Cubase to see if it might be the issue (DSI is fairly certain it is). Note that another user on Gearslutz (where I started researching this issue) was able to repeat the issues using his P12 and Cubase 7.5.20. A very specific interaction between Cubase and the P12 perhaps? Seems unlikely, but who knows.
Are there any sure-fire ways to identify/measure MIDI Clock issues? Any other suggestions? I’ve spent a lot of time on this and it’s fairly frustrating. I’d like to rule out any Cubase issues, if possible, before talking to DSI support again.
Thanks in advance for any ideas, suggestions or other input!