Why does my midi device have a long delay (cool-down period) between consecutive key presses?

Question

When pressing a key on my midi device and monitoring it in Midi-OX, it takes a long time (about 5 seconds) before it registers another input. Note that I'm nót talking about the delay between pressing a key and midi-OX registering it, but the delay between it registers another key after pressing one. A "cool-down period" so to speak before it recognizes another input.

I have used both Cubase and Midi-OX as software to monitor, and both have the same problem and "cool-down" period of around 5 seconds. I have tried both a PSR550 keyboard and a Yamaha Clavinova piano - again same result on both.

I use a Logilink UA0037N Adapter USB to Midi (In-Out, 1,9 m) to connect the keyboard/elec piano to my Medion Erazer laptop.

What could be the problem?

EDIT: As suggested I bought another cable: M-Audio USB Uno MIDI Interface 1 in/out. About twice as expensive (€30) and the best I could get. There is still the same delay. This cable does seem to be more sensitive for touch-sensitivity and pedals etc., but as soon as I press a key it will not react to another press (or release) for ~4 seconds.

The plot thickens though - anything other than the black-white keys on the Clavinova/PSR work perfectly fine. The pedals, buttons and pith-bender all work real-time.

Even stranger still - after any input óther than a key, the "cooldown" will reset and it will react to another key-press or release, at which point it stops reacting to any more key presses again.

So I've used different devices (PSR/Clavinova) different cables, different software (Cubase and Midi-OX) and different computers (tested everything with an old laptop as well that had usb2 instead of usb3 ports). I also looked in the PSR manual to set it to "midi output mode", which is apparently a specific mode for the keyboard when using it as a midi device. All setups and combinations have the exact same problem.

EDIT2: Turns out it WAS the cable. I just took my entire setup to a place that had dozens of different cables lying around, and eventually one worked normally. It seemed to be completely random which ones worked and which didn't though; some really cheap cables worked and some high-end brand ones didn't (though cheaper cables had the problem way more often). I really hate midi now.

Answer 1

5 seconds is beyond anything reasonable in normal operation. So we have to search for something outside of normal operation. What is common between your experiments? Obviously your computer. Then we have

I have tried both a PSR550 keyboard and a Yamaha Clavinova piano

which does not look like a commonality until we realise that a PSR550 is also from Yamaha. That makes it likely that both devices share the same kind of Midi interface and basic implementation.

Another commonality obviously is your USB-Midi interface. Looking for images of this device, it appears to be a branded copy of the standard cause for Midi problems, an adapter with a mixture of violin and bass clef on one side.

This adapter is known to garble Sysex messages and it is known to garble running status bytes which are used (among other things) for compressing note-off events into shorter Midi sequences by broadcasting them as note-on events with velocity 0.

This is the reason this garbage MIDI adapter tends to fall apart under polyphony when a keyboard utilises this sort of compression for sending notes in tight sequence.

My guess would be that either the keyboard or the adapter changes use or interpretation of running status bytes when a longer delay to the last byte has been interposed. It may well be that 5 seconds after the last note, the next note from the Yamaha keyboards will be sent without using running status byte compression (even though it would still be applicable) in order to avoid missing notes when someone replugs Midi connectors (which presumably tends to take at least 5 seconds, or at least people will not expect it to work immediately in case they are faster).

Either that, or the adapter has a timeout period after it got confused where it reverts to a sensible behavior.

It would appear that the Yamaha keyboards make the cheap adapter fall apart more conspicuously with even simpler use than what commonly makes it drop out. I would not blame the keyboard, really.

There are actually good brands for USB Midi adapters (like Roland, Yamaha, M-Audio) and lots of vintage USB1.1 adapters from those brands which are plenty fast enough at 12Mbps for most purposes (depending on the hub, you might want to avoid sharing a hub with a mouse or keyboard or other slow device). Get one of those preowned and forget about the cheap ubuquitous standard Chinese junk with the fantasy clef on it.

Answer 2

I can only guess but it's probably your midi interface.

midi/usb interfaces can be cheap - but if they're cheap... this'll happen. or at least things like this. you've tried another?

Answer 3

This cable does seem to be more sensitive for touch-sensitivity and pedals etc., but as soon as I press a key it will not react to another press (or release) for ~4 seconds. The plot thickens though - anything other than the black-white keys on the Clavinova/PSR work perfectly fine. The pedals, buttons and pith-bender all work real-time. Even stranger still - after any input óther than a key, the "cooldown" will reset and it will react to another key-press or release, at which point it stops reacting to any more key presses again.

What is the problem?

This actually points doubly strong to "running status byte" compression triggering the problem since interjecting a controller message will stop the opportunity for doing a running status byte. If the cable does not mess up the reception of this message, either the driver (are there remnants from your last USB cable's driver? Have you installed any drivers available for your current one? Usually no driver should really be necessary) or the application will be at fault.

Answer 4

"Running Status" is nothing that can be represented via USB Midi. If that is the source of the problem, it is the USB/Midi-Interface that messes this up. If your USB device string (in Linux visible with lsusb and in Windows somewhere in the device manager or something) indicates an M-Audio device, then M-Audio needs to get crossed off the list of recommendable manufacturers.

If it doesn't, it depends on whether your cable is genuine (and M-Audio indeed reverted to using bad third-party chips) to decide whether M-Audio is at fault for marking up generic garbage to a premium price tag after putting a different case on it.

I'd return it and see whether I can get something like a Terratec Midi One (which is only unidirectional and so, while handy and reliable, mostly applicable to simple uses) or one of the older preowned interfaces in a metal case (and typically with a full-size USB B socket).