The MPX 1 is a wonderful multi-effects processor made by the pro audio company Lexicon in the late 90s. Being a Lexicon piece, it obviously sounds great but the ability to route the signal between effects and dynamically control parameters is what sets this device apart. You can simply specify the order of the effects but you can also configure the device with two seperate signal paths that operate in parallel. This allows you to put seperate effects on the left and right channels but things get really interesting when you split the signal, process them seperately then mix them again at the end.

For effects, the MPX 1 includes excellent reverb (of course), modulation (chorusing, detune, etc..), EQ (shelf, parametric, moog) and delay. All of the parameters for these effects can be controlled dynamically via the Patching system, which uses built in LFOs, ADSRs, Envelopes, A/B triggers and a random number generator but also incoming MIDI (continuous controller, note, clock, aftertouch). Amazing control.

The MPX1 also has balanced/unbalanced analog IO and SPDIF for digital IO allowing you to connect the device into an all digital system for no signal loss. 

Note that the MPX G2 Guitar effects processor is a second generation version of the MPX 1 so it has all of the same great routing and patching with more DSP resources, lots of new effects, a digitally controllable analog amp simulatior and a lot more.

News:

• V1.10 ROMs
• Patching Quick Guide
• Quick Reference Guide.pdf

Documents:

• Delays - Detailed notes about using the delays
• Looping - Yes, you can actually loop with a MPX 1
• Parameters - Some general information
• Forum
• Users Guide
• MIDI Implementation

Tools:

• Bob Sellon's MIDI SysEx DumpTool (for moving programs between boxes like the MPX1 and a Windows based PC).
•  Wazware MIDI tools

Also see..

• Lexicon MPX 1 and MPX G2 Patching System
• Lexicon MPX 1 Parameters
• Lexicon MPX 1 Delays
• Lexicon MPX 1 Looping
• M-Audio USB Uno 1X1 MIDI Interface
• Lexicon MPX R1 MIDI Footpedal