The Lexicon MPX 1 is a 2-in/2-out multi-effects processor in a single rackspace chassis, built around what Lexicon calls its Multiple Processor FX technology. Its core selling point is reverb: Lexicon describes it as delivering "no compromise stereo reverb in combination with as many as 4 additional stereo effects," all running at once in a stereo in, stereo out configuration1. For a guitar player, that means one box can carry a Lexicon reverb alongside delay, modulation or other effects in a multi-effects setup, controlled from an interactive front panel rather than a menu dive.
Lexicon lists the MPX 1 as discontinued, so it is now a secondhand purchase1. The company still hosts a software download for it on the product page, released in July 2020 and sized at 117 KB1.
What the MPX 1 does
The MPX 1 is a reverb-first multi-effects unit. Lexicon's own description of its approach1:
"Multiple Processor FX technology combined with an interactive front panel, creates a new set of standards for others to follow"1
Lexicon product page1
In practice, the unit runs a stereo reverb algorithm and stacks as many as four more stereo effects alongside it, all in one program1. It ships with 200 preset programs, which Lexicon says are "designed for a wide variety of audio sources and applications," with database sorting to help you find the right one quickly1. That preset count and the sorting system matter for live use, where finding a specific patch between songs has to be fast.
Inputs, outputs and digital I/O
The rear panel is where the MPX 1 shows its studio heritage. Analog audio connections use XLR and 1/4" balanced (T/R/S) inputs and outputs, and there is a digital path in and out via coaxial RCA connectors1.
| Connection | Details |
|---|---|
| Analog inputs | XLR and 1/4" balanced (T/R/S) |
| Analog outputs | XLR and 1/4" balanced (T/R/S) |
| Digital input | Coaxial RCA, 24-bit S/PDIF, 44.1kHz |
| Digital output | Coaxial RCA |
| MIDI | 7-pin DIN for MIDI IN and powered bidirectional remote; 5-pin DIN for MIDI THRU and OUT |
| Footswitch | 1/4" T/R/S connector for bypass and tap |
| Footpedal | 1/4" T/R/S connector, 10kΩ to 100kΩ impedance |
| Remote power in | 2.5 mm, 9 volts AC (not included) |
A few points worth a player's attention. The 7-pin MIDI IN connector carries power for a bidirectional remote along with the MIDI data, which is how Lexicon supported a dedicated remote controller without a separate wall wart at the rack; the remote's 9V AC supply is not included1. The footswitch jack handles both bypass and tap tempo, so one switch on the floor covers the two things a guitarist most wants at their feet1. An expression pedal with 10kΩ to 100kΩ impedance plugs straight in1.
The S/PDIF digital output uses a coaxial RCA connection1, so it connects to interfaces and converters with a matching coaxial S/PDIF input.
Audio specifications
| Specification | Value |
|---|---|
| Input level | -2dBu to +20dBu balanced; -14dBu to +8dBu unbalanced |
| Output level | +18dBu |
| Input impedance | 100kΩ balanced; 50kΩ unbalanced |
| Output impedance | 600Ω unbalanced |
| Frequency response | 20Hz to 20kHz ±1dB |
| THD | 0.01%, 20Hz to 20kHz |
| Dynamic range | D/A >95dB, A/D >90dB, A/A >95dB typical, 20Hz to 20kHz, unweighted |
| Crosstalk | -60dB |
| Internal audio DSP | 20-bit; 32-bit |
| Conversion | 24-bit A/D; 24-bit D/A |
The wide balanced input range (-2dBu to +20dBu) and +18dBu output level line up with pro studio gear rather than guitar-level signals, so the MPX 1 is happiest at line level, in a rack loop or after a preamp, rather than directly after a guitar pickup1. The 0.01% THD and ±1dB frequency response figures are the kind of clean, transparent performance you expect from a studio processor: the unit is designed not to color the sound except where you ask it to1.
Environmental limits are also specified: operating temperature of 32 to 104°F (0 to 40°C) and maximum humidity of 95% without condensation1, which covers normal stage and studio conditions.
Videos
조복규
Leon Todd
Fender Studio
Questions
Is the Lexicon MPX 1 still made?
No. Lexicon lists the MPX 1 as discontinued on its product page, so units are found on the secondhand market. Lexicon still hosts a software download for it, released in July 2020, on the same page.
How many presets does the Lexicon MPX 1 have?
It carries 200 preset programs, which Lexicon says are designed for a wide variety of audio sources and applications. A database sorting feature helps you find the preset you want among them.
Can I use a footswitch for tap tempo on the MPX 1?
Yes. The rear panel has a 1/4 inch T/R/S footswitch connector that handles both bypass and tap, so a single footswitch covers tempo entry and bypassing the unit from your pedalboard or rack.
Does the MPX 1 have a digital S/PDIF input?
Yes. The digital audio input is a coaxial RCA jack carrying 24-bit S/PDIF at a 44.1kHz sample rate. There is also a coaxial RCA digital output, so the unit can sit in a digital signal chain in both directions.
How many rack spaces does the Lexicon MPX 1 take?
It takes one rack space (1U). The chassis measures 19 inches wide by 1.75 inches high by 9 inches deep, or 483 x 45 x 289 mm, and weighs 6.125 lbs (2.8 kg).
Where can I download MPX 1 software updates?
Lexicon hosts the MPX 1 software on its own product page at lexiconpro.com. The posted release is dated July 2020 and is a 117 KB download, so it is a small firmware file rather than a large bundle.
Sources (1)
- MPX1 | Lexicon Pro - Legendary Reverb and Effects | English, Lexicon Pro (lexiconpro.com), 2020