Midi to USB midi interface vs USB midi built-in

I made the same remarks in another thread regarding note-off and damper pedal. Note-off in the D1 is fixed a 64. This is apparent in the midi-table in the manual (which you can find online).
The damper-pedal that comes with the D1 is an on-off pedal (so basically a switch). The D1 however will accept a half-damper pedal. I have the D1 with Korg's DS1H pedal, and that combo works fine, it goes through all 127 midi levels, and when calibrating, Pianoteq recognizes it. It's also a better pedal (larger, heavier) than the one shipped with the D1.
It is true that the D1 is not suitable for a three-pedal unit (not Korg's own PU-2 or a third-party unit). The control changes (66, 67) for sostenuto and soft are listed in the midi table in the manual as not supported.

Hello RobertS,

the initial question is hard to answer. First you have to find a person, who has a keyboard-controller with two MIDI-Interfaces: DIN-MIDI and USB-MIDI.
Then an external MIDI-to-USB adaptor is required.

You have to trust that person, that it is able to "hear" MIDI jitter and to "hear" MIDI latency.

Even if you trust for some unknown reason, we don't know anything about the quality of the external MIDI-to-USB adaptor and quality of the internal MIDI-to-USB implementation in the keyboard. Take another adaptor and another keyboard and another person and the result may be completely different.

A measurement would be clearer. But who really can measure MIDI-jitter and -latency in situ?

Unless we have measurements, we can just try some generalization:

* It should not make a difference, if the MIDI-to-USB conversion is done inside or outside a keyboard. Probably the same (old & cheap) technology is used.

* Many MIDI-to-USB converters are using USB 1.x, which has a packet latency of 4 ms. DIN-MIDI has a resolution of ~1 ms, so USB conversion takes a few milliseconds of time more (minimum).

* MIDI-jitter might be higher when USB is included (randomly a MIDI-event reaches the current USB-packet or the 4 ms delayed next).

Thanks all for your responses. In theory it seems there should be not much of a difference, but in reality at least with my experience with vintage synth using more primitive midi gear indicates the contrary. I remember more than 10 years ago connecting several vintage synth daisy chaining midi cables and the latency was very obvious and proportional to the distance of the daisy chained cables. I also remember that avoiding Midi Thru and getting shorter midi cables connected from one multi port midi interface minimized the latency, but still there was a latency there that was noticeable. I also remember trying with different sizes of midi cables and very short midi cables (less than one meter) were much better than other cables of 3 meters. I ended up connecting my Korg Oasys 88 with a 30 cm midi cable to the interface and I always felt I was able to record tighter, more accurate Pianoteq takes with less jitter and less latency.

All these issues disappeared or were vastly improved as I started using midi thru USB cables. But I always tried with vintage keyboards, never with a new one like the Korg D1 or the Kawai ES110 and a new midi interface. Guess it is a matter of trying!

I will get a Korg D1 with a midi to USB cable so I will be able to compare it with other keyboards I have with the the midi interface built-in and will share here my subjective findings.

If I remaber well a good circuit take 0,5ms or 1ms to convert MIDI to USB or analogic to digital.

Thanks! This sounds very interesting. Though I had not noticed that it only has one pedal socket for half pedaling! This along the fact that it lacks a built int USB port and it hasn't note off velocity it seems there are too many compromises for me to accept.

That both MIDI OUTs (USB and DIN) are not usable at the same time is probably a sign, that the USB-MIDI-OUT of the Yamaha ist just carried out by an internal MIDI-to-USB-adaptor *inside* the keyboard.

If your "feeling" doesn't deceive you, this could mean that the internal keyboard MIDI-to-USB has a better MIDI latency and/or better MIDI jitter than the external OTraki MIDI-to-USB converter (given all your other devices in your chain, like USB-HUBs and MIDI-Mergers are 100% identical).

If you are having spare time in the next weeks, you could make a more objective experiment: The idea is to loopback the MIDI-out to the MIDI-in. When the keyboards tonegenerator is MIDI-Local-On you should hear two sounds - the native and the loopbacked a few milliseconds later.

If you record this tones with a waverecorder (like Audacity) you should see two wavs with a few milliseconds distance. Which will have the shorter soundgap in your soundsystem - the DIN-MIDI-loopback or the USB-MIDI-loopback?

Thanks for your little experiment.

Thanks for the interesting experiment. This implies the time it takes from the moment the key is hit til the moment the DAC plays the sound a constant. Also the loopback time is considered to be constant. But they may not be constants, specially the loopback time where the computer expectedly won't be as busy in both moments so it may not take the same time to perform the same task.

The point was to discuss the latency from the moment a key is press til the moment Pianoteq produces the sound. In a real acoustic the "latency" would be the time taken from the moment the hammer hits the cords til the moment the cords start vibrating producing sound. So there will be a little latency.

In my opinion the best way to measure the real latency of a midi keyboard would be to take a mobile phone, place it near the keyboard and start recording audio. Then press hard a keyboard key, so it will record the sound from hitting the key and then it will record the sound from the speakers playing the Pianoteq note. Then from the audio editor calculate the time taken from the moment of the first noise hitting the key til the moment the first part of the sound shows up in the waveform. Then deducting from the total time the output latency of the audio driver as reported by the DAW, it should give the real incoming midi latency of the system.

Hi RobertS,

I just speak for my system tested. The midi roundtrip times were reproducible, I tried it several times and with several midi notes. The audio from the usbmidi loopback has always been 6 ms behind the audio of the DigitalPiano triggered from the internal keyboard.

The USB-connected notebook had realtime scheduling and a linux kernel with 1000 Hz system-timer. The only significant application running was jackd with connection window open to loopconnect the B2's MIDI-OUT and MIDI-IN.
So not a system I would call "busy".

The key press was eliminated in my experiment, because the timing starts from the moment a MIDI note-on event is triggered (at the end of the key movement, when the last key contact has been closed).

But of course it is not more than one real life snapshot of the second half of your topic: "vs USB midi built-in".

End-to-end audio recordings (fingernail to speaker) were made several times in other threads of this forum. If you are more interested in those you can use the search function with string "latency" and user "groovy" ;-)

cheers