SansAmp, Micro lite won't play together but MIDISport works

[Audios]

Hi, I had a very strange involving Bome MIDI Translator (MT), a SansAmp PSA 1.1, and my MOTU Micro lite. I eventually narrowed down the problem to the Micro lite so I thought I’d mention it in case others had a similar problem.

I’m running MT V1.72 on my Windows 7, 64-bit PC. My PC is connected via USB to a MOTU Micro lite, the output of which goes to a SansAmp PSA 1.1. The MIDI Through of the SansAmp goes to the input of a Lexicon MX300. For debugging purposes, both the SansAmp and MX300 are set to receive on all MIDI channels to remove the possibility of a channel assignment error so both should respond identically to Program Change commands. Note that when the MX300 responds, it confirms that my PC has sent a Program Change command since it’s at the very end of the MIDI chain; it also confirms I don’t have a cabling problem.

On the input side, I have a Roland FC-300 foot controller sending Program Changes commands to MT via the MOTU Micro lite.

When I use MT as a MIDI router, i.e. I have an input of the Micro lite routed to an output of the Micro lite, everything works fine. Pressing on my FC-300 causes both my SansAmp and MX300 to change programs simultaneously.

My problem is when I use a MT translator rule to do the same thing, e.g. to intercept a program change message from the FC-300 and output a program change message. When I do so, the SansAmp responds to the first message (as does my MX300) but subsequent messages are ignored—but only by the SansAmp!!!! The MX300 responds to all of the messages.

When I shut down MT and restart it, it automatically loads the most recent translator. Without changing any settings after a restart, when I generate a program change event using the FC300, the SansAmp responds to the first Program Change message but ignores any subsequent ones. The MX300, as before, responds to every message. The SansAmp failure-to-respond suggests there is something different about the first message but the MX300 responds to all of them--so what gives???

I tried different wiring setups (e.g. putting the MX300 ahead of the SansAmp in the MIDI chain, disconnecting the MX300 altogether, using different Micro lite ports, etc.) but the results were consistently the same: the SansAmp wouldn’t respond to anything other than the first Program Change message that is generated by an MT translator, but it responds to every Program Change message when MT is in Router mode.

I thought this might be an MT bug so I posted a bit longer description of it on the Bome forum, but shortly afterwards I tried using an M-Audio MIDISport, just by swapping cables and adjusting my port settings in MT (since the Micro lite ports were no longer available). Suddenly, everything worked fine!

To verify it wasn’t a MOTU driver problem, I deleted (what turned out to be the latest) driver using Device Manager, downloaded and reinstalled the latest for Win7 64-bit, rebooted, swapped the cables back over to the Micro lite, and I had the problem again, i.e. the SansAmp would only respond to the first program change message but the MX300 worked every time.

Lastly, I swapped the MIDISport back in and everything worked again. I can only conclude the MOTU has a problem but who knows if it’s a driver bug or something harder to diagnose.

Audios