[sdiy] Tools for testing MIDI

[brianw]

I assume that you're referring to MIDI merge.

MIDI through is purely electrical, with no latency. The caveat is that MIDI thru does not merge MIDI out with MIDI in unless something different is designed.

It might be worth pointing out that MIDI Clock is still legal even in the middle of a long SysEx data dump. MIDI System Real Time messages like MIDI Clock can occur *anywhere* - so a MIDI merge function can still get accurate clock with average jitter of 160 microseconds (0.16 milliseconds) even when passing through.

That said, there are plenty of real MIDI products on the market that drop the ball. I just hope that modern designs can get all of these little details right.

Brian


On May 21, 2026, at 12:56 PM, Florian Anwander wrote:
> If the device creates other data then this is still doable. The real challenge for a MIDI clock generator is handling MIDI-thru...
> 
> Am 20.05.26 um 22:46 schrieb Tom Wiltshire:
>> If it's *not* only sending MIDI clock, get it sending *everything* else it can possibly send all at once, and then make it pass through a massive Sysex data dump from somewhere else too. If it survives that, it's better than 95% of the MIDI stuff that's out there!