External Instrument Latency

Hey all,

I mention this problem on another old post and have not received any responses so thought I would start a new Topic to see if anyone can help me.

I have created 5 external instrument midi devices each connecting a separate midi port to a physical synthesizer (they are all rack mount synths without keyboards).

Dell PC - Intel i7-6700 3.40GHz
Memory - 64GB
Using SSD Drives
Motu 828mk3 with Focusrite OctoPre Mkii audio interface
MidiSport 8x8/s Midi interface

Windows 10
Cubase 8.04


  1. When I first start Cubase 8 all the synths respond to my midi controller (Roland A-90) with no or so little latency that I don’t hear it.
  2. After playing on any of the instruments for a minute or so, all the synths have about a .25 second latency. If I switch over to a VST Virtual instrument there is no latency.
  3. If I quit playing for a while the latency goes away.
  4. If I start playing again the latency comes back.

It seems like a buffer problem to me and there is probably a setting somewhere that will correct the problem, but I have not been able to identify it.

Any Ideas???



Could you avoid MIDISPORT and connect at least one of your synths via USB directly? Just to make sure it’s(not) on MIDISPORT side.


I thought of that but two things…

  1. All the synths are old school and only have Midi Ports, no USB ports.
  2. This same setup work just fine in Ableton.

Actually this configuration use to work. I am guessing that I tweaked a parameter somewhere, by accident, and just didn’t know I had done it. I thought it might have to do with when I added the Ivory VST because it happened at about that time. I have since removed the Ivory VST and have setup a configuration with just a single hardware synth midi device. Neither of these things have worked.

What I haven’t tried is deleting all the midi devices and set it up with two channels per instrument, one for midi and one for audio. I hope to give that a try tonight.

I have deleted the Midi Devices and now am connecting directly using 2 tracks, a midi track and an audio track. Nothing has changed and it is still broken.

Is there something like a “Factory Reset” where I can set everything back to the way it was when I first installed or do I just have to install everything all over again. I fell almost certain there is a setting that is off but I just can’t seem to find it.

Yes, use Safe Start Mode, please.