Lexicon MPX 100 User manual

User Guide
MPX 100 Dual Channel Processor
Stereo 44.1kHz S/PDIF Digital Output

Lexicon Part #070-11935
Unpacking and Inspection
After unpacking the unit, save all packing materials in case youever need to re-ship. Thoroughly inspect the unit and packing materials for signs of damage.
Report any shipment damage to the carrier at once; report equipment malfunction to your dealer.
Notice
This equipment generates and uses radio frequency energy and if not installed and used properly, that is, in strict accordance with the manufacturer's instructions, may cause
interference to radio and television reception. It has been type tested and found to comply with the limits for a Class B computing device in accordance with the specifications in
Subpart J of Part 15 of FCC Rules, which are designated to provide reasonable protection against such interference in a residential installation. However, there is no guarantee
thatinterferencewillnotoccurinaparticularinstallation.Ifthisequipmentdoescauseinterferencetoradioortelevisionreception,whichcanbedeterminedbyturningtheequipment
OFF and ON, the user isencouraged to try tocorrect the interference by one or more of the following measures: reorient the receiving antenna; relocate the computerwith respect
to the receiver; move the computer away from the receiver; plug the computerinto a different outlet sothat the computer and receiver are on different branch circuits. If necessary,
the user should consult the dealer or an experienced radio/television technician for additional suggestions. The user may find the following booklet prepared by the Federal
Communications Commission helpful: "How to identify and Resolve Radio/TV Interference Problems." This booklet is available from the U.S. Government Printing Office,
Washington, DC 20402, Stock No. 004-000-00345-4.
Le présent appareil numérique n'émet pas de bruits radioélectriques dépassant les limites applicables aux appareils numériques de la class B prescrites dans le Règlement sur
le brouillage radioélectrique édicté par le ministère des Communications du Canada.
Acknowledgement
All product names indicated by a Trade Mark are registered by their respective manufacturers.
Lexicon Inc.
3 Oak Park
Bedford MA 01730 USA
Telephone [phone]
Fax [phone]
Copyright 1998, Lexicon Inc.
All Rights Reserved.

Program Descriptions............................................................17
Single Programs ..................................................................18
Dual Programs.....................................................................32
Special FX ...........................................................................41
User Programs ....................................................................42
Restoring Factory Defaults
MIDI Operation........................................................................43
MPX 100 MIDI Behavior...........................................................43
Assigning a MIDI Channel for Program Load...........................44
Using Program Change Messages for Program Load
Learning Continuous Controllers..............................................46
Activating Bypass or Tap Functions with Program Change
Messages ............................................................................47
Clearing a Learned Assignment...............................................48
MIDI Clock................................................................................49
MIDI Dumps .............................................................................49
MIDI Implementation Chart ......................................................50
Specifications.........................................................................52
Getting Started .........................................................................1
Introduction............................................................................1
Front Panel Overview ............................................................2
Setting Audio Levels
Rear Panel Connections........................................................4
Audio Connections • Headphones • Footswitch
Basic Operation........................................................................7
Selecting Programs ...............................................................7
Single Programs • Dual Programs • User Programs
Editing ...................................................................................9
Tap Tempo Functions: Varying the rhythm • Audio
Tap • Setting Tempo via MIDI
Bypass.................................................................................11
Storing Programs.................................................................12
System Mode ..........................................................................13
System Mode Parameters ...................................................14
Bypass • Patching • Program Load • Digital Output
MIDI OUT/THRU • MIDI Pgm Change • MIDI Clock
Receive • Tempo • MIDI Dumps
Table of Contents

Getting Started
1
Introduction
ThankyouforyourpurchaseoftheMPX
100 Dual Channel Processor.
The MPX 100 is a true stereo dual-
channel processor with 24-bit internal pro-
cessing, 20-bit A/D-D/A and S/PDIF digital
output.PoweredbyanewversionofLexicon’s
proprietaryLexichip™,theMPX100has240
presetswithclassicreverbprogramssuchas
Ambience, Plate, Chamber and Inverse, as
well as Tremolo, Rotary, Chorus, Flange,
Pitch, Detune, 5.7 second Delay and Echo.
Dual-channel processing gives you two in-
dependent effects in a variety of configura-
tions:DualStereo(Parallel),Cascade,Mono
Split and Dual Mono. To make sure you get the most
out of the MPX 100, be sure to
read the manual.
A front panel Adjust knob allows instant
manipulationofeachpreset’scriticalparam-
eters and an Effects Lvl/Bal knob lets you
control effect level or the balance of dual
effect combinations. An easy Learn mode
allows MIDI patching of front panel controls.
In addition, tempo-controlled delays and
modulation rates lock to Tap or MIDI clock,
and Tap tempos can be controlled by audio
input, the front panel Tap button, dual
footswitch, external MIDI controller or MIDI
Program Change.
Other features include dual 2-stage
headroomindicators,a headphoneoutput,a
software-selectable MIDI OUT/THRU port,
pushbutton or footswitch selection of dry or
mutedaudiooutputanda20Hz-20kHz±1dB
Frequency Response.

Input
Setsthe levelof theincoming
signal. LEDs indicate accept-
able signal level (green), or
clipping (red).
Output
Controls the analog output level.
Front Panel Overview
VARIATION
Selects program variations for the effect bank cur-
rently selected by the PROGRAM knob (8 variations
foreachSingleeffectand16 variationsforeachDual
effect). When PROGRAMisset to User,selectsone
of 16 memory locations for user programs.
Mix
Controls the proportion of processed
(wet) to unprocessed (dry) signals.
TAP
Flashes for tempo-
based programs. Press
twice to set a tempo.
Hold to have input level
determine tempo.
(When pressed with
Store activates MIDI
Learn.)
Bypass
Mutes or bypasses the signal depending on the
setting of the SystemBypass parameter. (Press for
2 seconds to access System Parameters.)
2
Effects Lvl/Bal
Sets the level of the Single
effects and the balance of
the Dual effects.
PROGRAM
Selects program banks
(Single, Dual, or User).
Store
Initiates store procedure.
(WhenpressedwithTap,ac-
tivates MIDI Learn.)
Edit LED
Lights to indicate
program is altered
but not stored.
Adjust
Modifies the param-
eters of the current
program.

Setting Audio Levels
1. Start with INPUT set to 9:00 o'clock and
OUTPUTallthewaydown(fully counter-
clockwise).
2. Set the instrument output or effectssend
being input to the MPX 100 to a nominal
level and play, or send audio to the MPX
100.TheLevelLEDs*shouldlightgreen.
IftheClipLEDs light redatthispoint,turn
down the output of the instrument or
effects send until the Clip LEDs remain
off during the loudest passages.
3
*TheLevelLEDsare offwhentheincomingsignal
is low (more than 30dB below overload). TheClip
LEDs light red when the signal approaches over-
load (-2.5dB). Acceptable signals will cause the
Level LEDs to light green almost continuously,
with the Clip LEDs flashing red on peaks.
3. Whilestillsendingaudio tothe MPX100,
gradually turn up the INPUT control until
the Clip LEDs show red on only the
loudest peaks.
4. Set the MIX control to Dry.
5. Turn OUTPUT to the desired level.
6. IftheMPX100isusingaconsole’ssends
and returns, set the MIX control fully
clockwise(100%wet).Ifyouareusingan
instrument amplifier, start with MIX set
halfway up.
As with any audio product, it is good
practice to first power on all outboard
gear, then the mixer, then any loud-
speakers.

Rear Panel Connections
4
MIDI
Two 5-pin DIN MIDI connectors
are provided for MIDI IN and soft-
ware selectable MIDI OUT/THRU.
POWER
Use Lexicon 9VACpower pack.
OUPUT
Single-ended (unbalanced) stereo outputs provide +8dBu
typical output level. Use the right output connector for mono
output. If no connection is made at the right output, the left
output can be used to drive headphones at modest volume.
FOOTSWITCH
1/4" TRS connector, for momentary con-
tact footswitch, allows footswitch control
of front panel Tap and Bypass functions.
INPUT
Single-ended (unbalanced) inputs accept levels
aslowas -30dBu.Inputimpedanceis500kΩ.Use
the right input for mono sources. Can be used as
direct input for guitar.
DIGITAL OUTPUT
RCA S/PDIF connector.

Headphones
A stereo signal which is adequate to drive
headphones is available at the left output
(provided no connections are made through
the right output). This feature is provided as
a convenience for practice purposes, and is
intended to provide only modest volume.
Audio Connections
Audio connections to the MPX 100 are
unbalanced and should be made with high
quality shielded cables with 1/4" tip-sleeve
phone plugs at the MPX 100 end.
TheMPX100produceseffectsfromeither
monoorstereosources. Withmonosources,
the dry signal appears, along with audio ef-
fects, at both outputs. For instruments and
sourceswithstereooutputs,usebothinputs.
We recommend using the outputs in stereo
wheneverstereoinputs areused,butifmono
output is required, use the right output jack.
The left and right signals are summed inter-
nally when only the right output is used.
Footswitch
A footswitch connected via the rear-panel
footswitch jack allows control of Tap and
Bypass. A momentary footswitch can be
wiredtoatip-ring-sleeveconnector.Astereo
Y-connector allows two identical single
switches to be used.
Power off the MPX 100 before plugging in
the footswitch. (Otherwise, Bypass will be
enabled.)
5
A dual-function footswitch with a set of labels
to identify footswitch functionality (Tap and
Bypass) is available from Lexicon dealers.

Modes of Operation
6
TheMPX100canbeusedastwoindepen-
dent Effects Processors with Dual Program
Variations 11-16. Designate two auxiliary
sends on your console and connect one to
the left MPX 100 input, and the other to the
right input. Refer to the Program Descrip-
tionstotakeadvantage of thisconfiguration.
Connecting to a Balanced Console
Mono Guitar Input with
Mono or Stereo Amplifiers Dual Processor Setup with a Console

Basic Operation
7
Use the PROGRAM knob to
select the Single, Dual or
User effect you want.
Turn VARATION to
select one of 16
programs.
Selecting Programs
All of the programs on the MPX 100 are
selectedwiththefrontpanelPROGRAMand
VARIATION knobs.
The PROGRAM knob selects Single or
Dual program banks. The VARIATION knob
selects different program versions.
The Single selections are arranged
around the left side of the PROGRAM knob;
the Dual selections and the User bank are
arranged around the right side of the knob.
Single Programs
WhenaSingleprogram isselected, turn-
ingtheVARIATIONknob topositions1-8will
load eight versions of the first effect; posi-
tions 9-16 will load eight versions of the
second effect.
For example, when Plate, Gate is se-
lected, VARIATION 1-8 will load eight differ-
ent Plate programs; VARIATION 9-16 will
load eight different Gate programs.
WhenSpecialFXis selected,theVARIA-
TION knob will load 16 different programs
(one at each knob position).