While working on the Lexicon LXP-1 editor, I noticed that all of the midi messages were coming back as a through message. Great news! Midi is working as expected. However, I need to put this into out mode so thought I’d flick the switch.
I turned the Lexicon around, had a look and could not find it. I then went back to the manual and sigh, page 1-3 states:
MIDI THRU. Any data received at the MIDI IN connector is sent here without change. An internal jumper can be set to change this into a MIDI OUT con nector.
Lexicon LXP-1 User Manual, p1-3
Oh joy.
I have to open up the Lexicon and change a jumper. I really cannot understand why there is not a switch on outside because it is such a well programmed box in relation to midi.
After a quick Google, I found the following from the service manual:
This test requires internal jumpering to allow a MIDI OUT function to be performed instead of the factory-set MIDI THRU function. To prepare the LXP-1 for this test, perform the the following:
- Open the unit and locate internal jumper pins W2 & W3 on the pc board near MIDI jacks.
- Move internal jumper location at W3 to W2,
- Connect a MIDI cable from the jack labeled: MIDI IN to the jack labeled: MIDI THRU.
…Remove the internal jumper from W2 and reset to W3 to restore the LXP-1 MIDI THRU function. …
Lexicon LXP-1 Service Manual, page 2-3
So the next stage is opening it up safely, so that I can change that jumper.
Okay, so I now know the problem. My next question is, how difficult is it to open an LXP-1.
According to AI, the solution for this is as follows:
To open a Lexicon LXP-1, you need to first remove all the nuts and washers from the rear jacks, including the toothed washer with the flying lead that connects circuit common to the case, and then unhook that lead. Once this is done, the entire top, bottom, and side casing, which is a single extrusion, should slide off.
Step-by-step guide to opening the LXP-1:• Locate the rear panel: Turn the unit to access its rear panel. • Remove rear panel hardware: Unscrew and remove all the nuts and washers from the rear jacks. • Identify the flying lead: Look for a flying lead connected to one of the rear jacks, which has a toothed washer on it. This lead connects the circuit common to the case. • Unhook the flying lead: Carefully unhook this flying lead from its connection point. • Slide off the casing: With the lead disconnected, the entire outer casing of the LXP-1 should now be able to slide off.
Okay, so not so bad after all. A little bit of a pain but seems okay.
Due to AI being AI in 2025, best to cross reference. I found a good thread on Gearspace which can be found here (link). From David Rick
It’s been over a decade since I had to repair one, but my recollection is that the top, bottom, and sides are a single extrusion that slides off. You need to remove all the nuts and washers from the rear jacks, and there’s also a toothed washer over one of the jacks with a flying lead that connects circuit common to the case. Unhook that and the whole thing should slide apart.
Looks good.
I will photo and document.