Lexicon JamMan - Disable MIDI Clock

Included in the Jamman software is a set of diagnostics which are typically used by service technicians. Along with the diagnostic tests, however, there is a utility for changing the MIDI channel to which the system will respond as well as tool to disable the systems response to incoming MIDI clocks.

To enter diagnostics,
- press and hold the RESET/BYPASS and FUNCTION buttons while the system is powering up. The letter 'd' will appear on the display indicating that you have entered the diagnostics.
- Turn the right hand front panel encoder until the number 12 appears on the display then press the RESET/BYPASS button. This brings you to a special diagnostic tool that outputs a very fast MIDI clock for troubleshooting MIDI problems. If you press the FUNCTION button, however, the MIDI clock input will be disabled. - Press RESET/BYPASS a second time then turn the encoder to 9
- Press RESET/BYPASS one final time to exit diagnostics and run the normal software.

Yes, this is ugly as sin which is one of the reasons it has not shown up in any application notes so far. But if you are hard core, you just might find it useful. One additional down side to this feature and to the setting of the MIDI channel is that they must be set each time the Jamman is power cycled. If the sequencer can optionally disable its output of MIDI clock and also slave to MIDI clock, the setup step can be avoided all together. Simply use MIDI channel 1 (Jamman's default) on the sequencer for Jamman data only and set the sequencer to sync to external MIDI clock with MIDI clock out disabled.

With MIDI clock IN disabled, the sequencer and JamMan can be connected as shown above but JamMan will ignore the MIDI clocks being output by the sequencer and still recognize all of the control commands. With this setup the operator simply TAPs in the first loop and a whole series of complex commands can be programmed into the sequencer with no additional operator intervention except to play their perspective instrument.

The things that can be done with this setup are amazing. New loops can be initialized, LAYERING enabled, loops muted, etc... Commands from a MIDI foot controller can even be recorded into a sequencer in real-time using the following setup:

<----- MIDI Foot Controller --<
-> Sequencer -> JamMan ------->

The only requirement is that the foot controller passes MIDI clock through. The Lake Butler Mitigator and the ART foot pedals were found to work very well for control but tended to be a bit sluggish for setting the tempo because of the rubber around the buttons.