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).

8
Dual Programs
When one of the Dual Programs is se-
lected, the VARIATION knob will load 16
different programs, each containing two ef-
fects.
User Programs
When User is selected with the PRO-
GRAM knob, VARIATION selects 16
memory locations available for storing your
own programs.
(When shipped, User variations 1-16
contain duplicates of a selection of the fac-
tory-installed programs.)

Use Adjust to
edit the current
program.
EditingMPX100programsiseasy.We've
arranged the critical parameters of each
program under the front panel Adjust knob,
soallyouhavetodoisturntheknobtoadjust
the program to suit you.
Youcanalsoadjustthe levelof theSingle
programs,ortheEffectsBalanceoftheDual
programs with the Effects Lvl/Bal knob.
Changes made with either knob are rec-
ognized as edits, and will cause the front
panelEditLEDtolighttoalert you to the fact
that the program has been altered.
9
Editing
Turn Effects Lvl/Bal to
adjust the level of a
Single program... ...or the balance of the
two effects in a Dual
program
The Edit LED will light to show
that the program has been
altered from its stored state.

10
Tap Tempo Functions
Varying the Rhythm
The MPX 100 Tap Tempo feature al-
lows you to set the delay times and modula-
tion rates of tempo-based programs to the
beat of the music.
To set the tempo from the front panel,
simplypresstheTapbuttontwiceintimewith
the music. That’s your tempo.No more dial-
ing up what “could be” the delay time in
milliseconds—justtaptwice—theMPX100
will figure out the time for you. When you
wanttochangetempo, justtaptwiceagainin
the new rhythm.
Audio Tap
You can also use audio input to set the
tempo of the MPX 100 delay times.
1. Press and hold the Tap button for two
seconds. (The optional dual footswitch
lets you press and hold Tap without
taking your hands off your instrument. )
2. While holding down Tap, play 2 short
notes in rhythm, then release the Tap
button.
3. The MPX 100 automatically calculates
thetempofromthespacebetweenyour
two notes.
For live performances this is a must — an
easy way to set delay rates to follow your
rhythm.
Many factory programs are stored with
their own tempo rate. You can tap in a new
tempo (and store your version in a User
location) orset the MPX100 to always recall
the last tempo used and apply it to every
program. (See System Mode.)
WhenyouselectGlobalTempofromthe
MPX 100 System mode, the last tempo
tapped in will be applied to all programs with
tempo-controlledparameters.(Youwillknow
if a program is tempo-controllable because
the Tap button LED will flash when the pro-
gram is loaded.)
TheTap LEDwillflash whenever
a tempo-based preset is loaded.

11
Bypass
Setting Tempo via MIDI
WhenusedinconjunctionwiththeLearn
feature, Tap can be set remotely from any
MIDI device. MIDI controllers, such as
Lexicon's MPX R1 Foot Controller, can be
used to send Continuous Controller mes-
sages or Program Changes tothe MPX 100
or you can send Continuous Controller or
Program Change messages from thebutton
and fader moves of many mixing consoles.
The MPX 100 will Learn these messages
and allow you to set tempo via MIDI.
Pressing the front panelBypass button
will cause the MPX 100 to pass only dry,
unprocessed audio, or to mute the inputs to
the current effect.
The MPX 100 can also receive and
utilize MIDI Clock. So, when used with a
MIDI sequencer or drum machine, the
MPX 100 automatically adjusts its internal
tempo to match. (See MIDI Operation.)
A System Mode parameter determines
which of these two options is in effect. (See
System Mode.) Bypass functions can also
be activated by footswitch or via MIDI.
Bypass can be set to mute or
bypass effects.

12
Storing Programs
When you want to save a program,
pressStore.TheStore LEDwillflash slowly
toindicatethattheMPX100 store function is
armed.(Ifyouwanttoexitwithout saving the
current program, press Store again.)
TurnthePROGRAMknobtoUser,then
useVARIATIONtoselectoneofthe16User
locations.
PressStoreagaintosaveyourprogram
to the selected location (and overwrite the
programpreviouslystoredthere).TheStore
LED will flash rapidly while the store opera-
tion is completed. The store operation is
complete when the LED stops flashing and
turns off. The Edit LED will also turn off, as
the current program is now your saved ver-
sion.
Press Store.
The Store LED will
flash slowly.
Turn PROGRAM to User and use
VARIATION to select a User location.
Press Store again.
The Store LED will flash rapidly
while the store operation is
completed.

System parameters and MIDI dumps
are activated in System mode. To enter this
mode, press and hold Bypass for approxi-
mately 2 seconds. The Bypass and Store
LEDs will blink slowly to indicate you are in
System mode.
The adjustable parameters available in
this mode are shown in the chart on the
following page.
13
System Mode
Turn the VARIATION knob to select a
parameter.PressStoretotogglethestate of
the parameter, or to execute a MIDI dump.
The Edit LED will show the current state of
each parameter.
When you have finished editing param-
etersandarereadytoresumenormalopera-
tion, return the VARIATION knob to its prior
setting,oryouwillloadanewprogrambased
on its position when you exit System Mode.
(The Tap LED will light when VARIATION
matches its prior setting.)
To exit System Mode, Press Bypass. If
you have changed any System parameters,
the Store LED will flash rapidly.

14
Variation State when Edit LED is:
Setting Parameter On Off
1 Bypass Mute Bypass*
2 Patching Disabled Enabled*
3 Program Load Mute Bypass*
4 Digital Output Dry Wet*
5 MIDI OUT/THRU Out* Thru
6 MIDI Pgm Change Disabled Enabled*
7 MIDI Clock Receive Disabled Enabled*
8 Tempo Program* Global
MIDI Dumps (Press Store to Transmit)
14 Dump User Programs
15 Dump Current Program
16 Dump System and Learned patches
Press and hold Bypass
for 2 seconds... ...The Bypass and Store
LEDs will blink slowly to
indicate you are in
System mode.
Turn VARIATION to select a parameter.
System
parameters MIDI
Dumps
Press Store to
toggle the
parameter state
(or to execute a
MIDI dump).
System Mode Parameters
Turn VARIATION until the Tap LED goes on
to find the last loaded program...then press
Bypass to exit System Mode.
* Factory Default

15
System Mode Parameters
1 Bypass Mute/Bypass
This parameter sets the Bypass button (or
thefootswitch,orMIDIcontrollerassignedto
Bypass)tomutetheinputs,or to bypass the
processed audio (passing only dry audio to
the outputs).
2 Patching Disable/Enable
This parameter allows you to temporarily
suspend (Disable) and restore (Enable) any
Learned patches.
3 Program Load Mute/Bypass
This parameter determines whether the
MPX 100 will engage wet mute or simply
bypass processed audio during program
load.
4 Digital Output Dry/Wet
For certain recording and monitoring appli-
cations,thisparameterallows you tochoose
topassonlydryaudio,ortoresumeoutputof
the full, processed signal.
5 MIDI OUT/THRU Out/Thru
SetstherearpanelMIDIOUT/THRU jackfor
eitherMIDIOUT orMIDITHRUfunctionality.
6 MIDI Pgm Change Disable/Enable
The setting of this parameter determines
whether or not the MPX 100 will recognize
MIDIProgramChangemessagesforloading
programs.
7 MIDI Clock Receive Disable/Enable
The setting of this parameter determines
whether or not the MPX 100 will recognize
MIDI Clock messages.
8 Tempo Program/Global
Determineswhetherthecurrenttempoofthe
MPX 100 will be applied to all programs
(Global), or whether program-specific tem-
pos are restored on each program load.
14-16 MIDI Dumps
These selections allow you to execute MIDI
Dumps. See MIDI Operation.

16

17
The 240 programs in the MPX 100 are
designed to provide a full palette of high
caliber ambience, reverb, delay, pitch shift
and other effects. As you audition the pro-
grams, be sure to vary the Adjust knob.
The Adjust knob has beencarefully cus-
tomizedforeachindividualprogram.Inmany
cases it controls several effect parameters
simultaneouslytoprovidesimplecontrol ofa
complicatededitingprocess.InmanyCham-
ber and Room programs, for example, Ad-
just controls the "liveness" of the space by
changing decay, EQ and early reflections all
at the same time.
Program Descriptions
The behavior of the Adjust knob is also
customized for different functions. Some-
times it acts as a linear control (at its mini-
mum value when turned fully counterclock-
wise—likeavolumecontrol)andsometimes
it acts as a bi-polar control (at its minimum
value when centered — like a cut/boost EQ
control).
The following section provides a general
description of each MPX 100 programalong
with tables that detail all of the program
versions available with the VARIATIONS
knob. These details include the function of
the Adjust knob and the Tap button (for
variations that use tempo-controlled rate or
delay times).
... or it may increase
values as it is turned
to either side of its
center position.
Adjust can increase
values linearly...