MPX 550 4. S/PDIF IN and OUT Provide digital audio input and output. Two RCA S/PDIF connectors are available. The unit accepts inputs at 44.1 or 48kHz. 5. ANALOG OUTPUTs Provide analog audio output. Balanced outputs are available on either XLR or 1/4 inch Tip/Ring/Sleeve connectors. 6. ANALOG INPUTs Provide analog audio input. Balanced inputs are available on either XLR or 1/4 inch Tip/Ring/Sleeve connectors.

CONNECTING THE UNIT

The INPUT and OUTPUT connectors on the MPX 550 are 1/4 inch Tip/Ring/Sleeve and XLR sockets. Either may be used. Connections should be made utilizing high-quality shielded cables. The MPX 550 produces effects from either mono or stereo sources. Either input can be used for mono sources. It is recommended to use stereo outputs whenever possible. Only material with Dual Mono routing is designed for mono outputs. Use either output connector if mono output is required.
Power off the unit prior to connecting the footswitch; otherwise, Bypass functions will be enabled.

Dual-Function Footswitch

A dual-function footswitch with a set of labels to indicate Tap and Bypass functionality is available at Lexicon dealers or at www.lexicon.com.

BYPASS

FOOTSWITCH
A footswitch connected to the rear panel FOOTSWITCH connector can be used to control front panel Tap and Bypass functions. A momentary footswitch can be wired to a Tip/Ring/Sleeve connector. A stereo Y-connector allows two identical switches to be used.
TYPICAL CONNECTIONS TO A CONSOLE

LEFT Out

RIGHT Out
LEFT In Aux Send 1 Aux Send 2

RIGHT In

SETTING AUDIO LEVELS Note:
As with all audio products, it is good practice to first power on all outboard equipment, then the mixer, then the speakers.
Lexicon The Input Trim knob allows the unit to be driven by an input level within a range of +8 to +20dBu. The minimum setting (fully counterclockwise) should be optimal for +4dBu (balanced) inputs. The maximum setting (fully clockwise) should be optimal for -10dBV (unbalanced) inputs.

OUTPUT INPUT

1. Load Program 1. 2. Set the Mix parameter to Dry (Edit Page 1, EDIT knob 4). 3. Using high-level program material, begin with a low input level and advance it slowly. 4. When audible distortion is reached or when the display clip indicators light and remain lit, lower the input level until the clip meters appear only on the highest peaks. 1. Press the front panel System button to activate System Mode. Output Level, the first System Mode parameter, will be displayed. 2. Turn EDIT knob 3 to set the Output Level parameter. Unity gain for a +4dBu input device should be -12dB. 3. Press the System button again to deactivate System Mode.

Basic Operation

Selecting and Loading Programs. 2-2 Editing Programs. 2-3 The Adjust Parameter. 2-3 Storing Programs. 2-4 The Compressor. 2-5 Tap Tempo. 2-6
SELECTING AND LOADING PROGRAMS
When powered on, the unit will load the last program that was loaded during the previous operating session. To select another program, turn the front panel PROGRAM knob. When the PROGRAM knob is turned clockwise, the unit will cycle forward through programs in the selected bank, then proceed to cycle forward through programs in the next bank. When turned counterclockwise, the unit will cycle backward through programs in the selected bank, then proceed to cycle backward through programs in the previous bank. When the PROGRAM knob is pushed inward and turned, the unit will cycle through program banks.
Turn the PROGRAM knob clockwise to cycle forward through all programs.
Lexicon The name and number of the selected program appear on the front panel display (see page 1-6). The Load LED will light to indicate that the selected program is cued for loading. After 4 seconds, the front panel display will revert to showing the name and number of the loaded program. However, the Load LED will remain lit to indicate that the selected program is still cued for loading. The number of the cued program will appear in inverse video below the number of the currently loaded program. To load the cued program, press the front panel Load button. The unit can be configured to automatically load programs 3/4 second after the PROGRAM knob stops turning. To do this, set the System Mode parameter Auto Load to Enabled (see page 3-7).
Press and turn the PROGRAM knob to select a program bank.
Turn the PROGRAM knob counterclockwise to cycle backward through all programs.
THE "ADJUST" PARAMETER
An "Adjust" parameter has been customized for individual programs, and in most cases controls several parameters at once to handle complicated editing processes. For instance, "Adjust" controls the liveness of space in Chamber and Room programs by changing Decay, Early Reflections, and EQ simultaneously. The "Adjust" parameter is located on Edit Page 1 and controlled with EDIT knob 1. It appears in parenthesis, such as (MidRT) pictured at the right. When EDIT knob 1 is turned, the bottom line of the front panel display shows a more complete description of the parameter function in that program. The "Adjust" parameter is MIDI-compatible with a range of 0 to 127.

When storing a user program, allow the unit to complete the entire store process before powering the unit off. If the unit is power cycled during the process, all previously stored programs may be lost.
For most music material, the release time should be about four times longer than the attack time. Both must be long enough to accommodate the bass content of the music. If the compressor is set to react faster than the waveform of the music itself, the resulting changes in output level will re-shape the waveform enough to produce undesirable audio effects. For example, 80Hz has a period of 12ms. If this is a dominant component in the music, set both the attack and release parameters to at least 12ms, even higher for better results. The compressor acts on both the left and right channels at the same time, using the sum of the two channels as its trigger. Compression presets are available in the Cmprssr Bank (see page 4-31). For other compression-only effects, send compressor output into a Dly/Eko program with the Delay parameter set to 0. The compressor does not add propagation delay to the audio path. (Note the converters introduce about 2ms of propagation delay.)

THE COMPRESSOR

The compressor is available in all programs, except Dynamics. (Dynamics uses a different compression mechanism, explained on page 4-33.) The compressor sits in the wet component of the signal in front of the effects in the loaded program. It is controlled with four parameters: CmpRatio, Threshld, CmpAttk, and CmpRels. These parameters are located on the last Edit Page for each program, except those in the Cmprssr Bank. The ratio (CmpRatio) parameter can be set to ratios of 1:1 (off), 2:1, 3:1, 4:1, 5:1, and 10:1. The threshold (Threshld) parameter can be set within a 0 to -32dB range. These settings are relative to 0dBFS (digital saturation). The compressor is disabled if either the ratio parameter is set to 1:1 or the threshold parameter is set high enough to prevent the incoming signal from crossing the compression threshold. The attack (CmpAttk) and release (CmpRels) parameters determine how fast the compressor responds, within 3dB of the output level dictated by the incoming signal.

TAP TEMPO MATCHING RHYTHM
Tap Tempo can be used to match the delay times and modulation rates of tempo-based programs with those of the music. The Tap/Cancel button LED will flash whenever a tempo-based program is loaded. The current tempo rate appears in the top-right corner of the front panel display. It is not required to enter what "could be" the delay time in milliseconds. Just press the Tap/Cancel button twice, and the unit will calculate the appropriate delay time. To change tempo, press the Tap/Cancel button twice again in the new rhythm. Tempo can also be set with a footswitch (see page 1-10) or MIDI control device (see page 6-4).

AUDIO TAP

To use audio input to set tempo: 1. Press and hold the Tap/Cancel button until the message "Detecting audio." appears at the top of the front panel display. (The optional dual footswitch allows the musician to continue playing the instrument while pressing and holding the Tap button.) Tempo parameters available for the loaded program will also appear on the front panel display. 2. Still holding the Tap/Cancel button, play two short notes in rhythm. 3. Release the Tap/Cancel button. The message "Knob 3 to change" will appear at the top of the front panel display to indicate that EDIT knob 3 is now available to adjust tempo.
MPX 550 4. If desired, turn EDIT knob 3 to further adjust tempo in bpm (beats per minute). 5. Press the Tap/Cancel button to exit this mode.
parameter Tempo Mode to Global. The unit will ignore individual tempo settings and apply the current tempo setting to each program as it is loaded.
Audio tap is a must for live performances. It offers a simple method of setting delay times and modulation rates to match the music. The Bypass button can be used to force the unit to pass only dry audio, to mute the outputs immediately, or to mute the inputs to the loaded program. Its function depends on the setting of the System Mode parameter Bypass Mode (see page 3-5). When Bypass Mode is set to Dry, the unit sends only dry, unprocessed audio to the outputs. When set to Full Mute, the unit mutes the outputs. When set to Input Mute, the unit mutes the inputs only. Running effects will continue their natural decay. Bypass functions can also be activated with a footswitch (see page 1-10) or MIDI control device (see page 6-4).

Selects the MIDI Channel for MPX 550 messages. When set to Off, the unit ignores messages sent on all MIDI channels. When set within a range of 1 to 16, the unit responds to messages sent on the selected MIDI channel. When set to Omni, the unit responds to messages sent on all MIDI channels. MIDI Program Change (Enabled, Disabled, R1-MPX 1) Enables and disables MIDI Program Change messages. When set to Enabled, the unit responds to MIDI Program Change messages. When set to Disabled, the unit ignores MIDI Program Change messages, preventing accidental changes. When set to R1-MPX 1, the unit responds to program change messages from a Lexicon MPX R1 Foot Controller set to MPX 1 Mode.
Controls the function of the MIDI OUT/THRU connector. When set to Out, the unit can generate its own MIDI Dumps. When set to Thru, the unit can forward - but cannot generate or modify - MIDI messages. Operating Mode (Normal, Demo, Locked)
Controls front panel knobs and buttons. When set to Normal, front panel controls perform their normal functions. When set to Demo, front panel controls are placed in a continuous program load cycle for demonstration purposes. When set to Locked, front panel controls are locked to their current settings. When front panel controls are locked:
MPX 550 The front panel PROGRAM knob is still available for selecting user programs only. Programs stored in the User Bank are still available, but cannot be modified. The System Mode parameter Auto Load is set to Enabled. Bypass functions are still available. Tempo and Patches cannot be learned. System Mode can still be activated. Auto Load
(Enabled, Disabled) Determines whether the front panel Load button must be pressed to load selected programs. When set to Enabled, programs will automatically load 3/4 second after the PROGRAM knob stops turning. When set to Disabled, programs will not load until the Load button is pressed. Display Brightness Controls the brightness of the front panel display. Turn EDIT knob 3 clockwise to make the display darker, and counterclockwise to make the display brighter.
Changes to the Operating Mode parameter will not take effect until the unit has been powered off, then powered on again. Memory Protect (Enabled, Disabled)

Protects the User Bank from accidental changes. When set to Enabled, the unit prevents changes to the User Bank. However, it does not prevent changes to System Mode parameters, nor does it prevent the restoration of factory-default settings. Restoring default settings will still erase all programs stored in the User Bank. When set to Disabled, the unit does not prevent changes to the User Bank. 3-7

MIDI DUMPS

Dump User Bank (1-16, 17-32, 33-48, 49-64) Dump System Data
Executes a MIDI Dump of User Bank programs to an external MIDI device, such as a sequencer. These programs can be dumped back to the unit. This is useful to preserve User Bank programs from deletion prior to restoring default settings. User programs are dumped in groups of 16, depending on the group selected by EDIT knob 3. Once a group is selected, press the front panel Store button to execute the Dump. When dumped back, the group will be returned to its original User Bank location. Dump Current Program Executes a MIDI Dump of the currently active program. This allows programs to be saved to an external MIDI device. Press the front panel Store button to execute the dump. When dumped back, the program will automatically become the currently active program.
Executes a MIDI Dump of all System Mode settings and Learned Patches. Press the front panel Store button to execute the dump. When dumped back, the System Mode settings and Learned Patches will take effect immediately.

RESTORE DEFAULT COMMANDS

Clear User Bank Arms a procedure to erase the contents of the User Bank. Press the front panel Store button to execute this procedure and return the User Bank to its factory-default condition. This procedure cannot be executed when a User program is running or when the System Mode parameter Memory Protect is set to Enabled. Factory Init Arms a procedure to restore parameters, System Mode parameters, User Bank programs, and Learned Patches to their factory-default conditions. Press the front panel Store button to execute this procedure.

Program Descriptions

Single Programs. 4-2
Peak Expansion Compression Tape Saturation Level Meters Typical Mastering Dynamics Control Adjustment

Chamber Programs 30 Brick Wall 31 Basement 32 LiveConcert "Adjust" (HighCut) (HighCut) (Livenes) (MidRT) (Livenes) (Livenes) (Livenes) (Livenes) (Livenes) (MidRT) Tap Eko Delay Eko Delay Eko Delay

CHAMBER

Historically, recording studio chambers were oddly shaped rooms with a loudspeaker and set of microphones to collect ambience in various parts of the room. Stereo Chamber programs produce even, relatively dimensionless reverberation with little color change as sound decays. The initial diffusion is similar to Hall programs. However, the sense of size and space is much less obvious. This characteristic, coupled with the low color of the decay tail, makes these programs useful on a wide range of material - especially the spoken voice. Chamber programs give the spoken voice a noticeable increase in loudness with low color.
33 Drum Chamber 34 Moves on. 35 Live Chamber 36 VocalChambrVocalChambrWideChamber 39 PCM60: Large

AMBIENCE

Ambience adds warmth, spaciousness, and depth to a performance without coloring its direct sound. It is commonly used to add a room sound to recorded music and speech. In music recording, Ambience can realistically add distance to close-miced signals. Ambience programs simulate reflections from room surfaces with random reflections, a gradual decay of overall level, and a gradual narrowing of bandwidth. In these programs, the Mix control adds depth - emulating the movement of a coincident pair of microphones away from the sound source into the room. Ambience Programs 40 Announcer 41 VerySmallAmb 42 Small Amb 43 MidSizeAmb 44 Studio "D" 45 Bright Amb 46 Dark Amb 47 MarbleFoyer 48 Smooth Amb 49 Guitar Amb "Adjust" (HighCut) (HighCut) (HighCut) (HighCut) (HighCut) (Decay) (Decay) (Livenes) (Decay) (HighCut) Tap
Room Programs 50 Bedroom 51 Tiled Room 52 Studio "C" 53 Small Room 54 Studio "B" 55 Rehearsal Rm 56 Studio "A" 57 Large Room 58 Fat Space 59 Chunky Space "Adjust" (Walls) (LFBoost) (MidRT) (Livenes) (MidRT) (EQ) (MidRT) (EQ) (MidRT) (EQ) Tap
Room programs simulate actual rooms where there is a strong sense of being in a small, live place. These programs are useful on drums and percussion, and can also be applied to electric guitar tracks.

TREMOLO

Tremolo is a rhythmic change in loudness, commonly employed as an expressive technique by vocalists and wind instrument players. It is also one of the oldest effects, frequently used with electric guitar, electric piano, and occasionally vocals. Different tremolo effects are largely determined by the rate (fast or slow) and waveform shape (smooth or sharp) of the change in loudness. If the effect is used in a stereo mix, the left and right can be synchronized to produce dramatic side-toside motion. The Tremolo programs offer classic tremolo shapes, such as square, sawtooth, triangle, sine, and rectified sine. The synchronization of the left and right channels can be adjusted to produce mono and stereo effects. The Tap button sets tremolo rates, making it simple to match the tempo of the music. The "Adjust" parameter (Phase) sets left and right channel waveforms out-of-phase, resulting in a panning motion.

SPECIAL FX

Special FX Programs 105 Infinite 106 The Abyss 107 Jet Flange 108 Verb>Chorus 109 TapRot Dly 110 Fader Verb 111 Low Rumble 112 Ducker Verb 113 DuckerChorus 114 Stereo Stage 115 Echoes:Beats 116 Panning Dlys 117 DreamSequenc 118 Infinite Dly 119 Diffusor "Adjust" (HighCut) (Dtuning) (Resnce) (HighCut) (Time) (Level) (Decay) (Decay) (Resnce) (Width) (Delay) (FeedBk) (Pitch) (FeedBk) (Diffusn) Tap Eko Speed (Whole Note) Rate (Drum/Horn) Echo Delay Time Dly Time, Pan Rate

Delay Time (Whole Note)

The ideal setting for the Width parameter depends on the distance between the speakers at each side of the stage. The program loads with an assumed spacing of about 20 feet, with an adjustment range of 10 to 50 feet. The width setting assumes that most audience members are seated within about 30 degrees to either side of the stage centerline. If audience members are seated further to the sides of the stage, the setting can be increased. Otherwise, it should be kept as low as possible.

STEREO STAGE

Stereo Stage provides stereo reverb while preserving the dry signal. To use this program, note the following: Use the MPX 550 in line between the mixer and house amplifiers - not as an effect mixed back into the main left and right channels on the mixer. Pan the input channels on the mixer fully to each musicians side of the stage. Keep the Mix parameter set to 50% (the default Program Load Mode setting). Adjust reverb level by setting the Efx Bal parameter between 100:0% (full left) and 60:40%.

DUAL PROGRAMS

The dual programs combine Delay with Reverb, or either Delay or Reverb with Flange, Pitch, or Chorus. Four routing configurations are used in the variations of each dual program: Dual Stereo (Parallel), Cascade, Mono Split, and Dual Mono. Flng-Dly, Pch-Dly, Chor-Dly, Dly-Rvb, Flng-Rvb, Pch-Rvb, and Chor-Rvb The first six programs in these banks feature two effects arranged in Dual Stereo (Parallel) configuration. Both effects receive signals from the left and right inputs, and both effects send signals to the left and right outputs. The last four programs in these banks feature two effects arranged in Cascade configuration. The first effect passes its signal to the second effect. For example, in Flng-Dly, Flange passes its signal to Delay. MSplit Dly, MSplit Rvb
These banks contain programs that are arranged in Mono Split configuration, which is similar to the Dual Stereo (Parallel) configuration. One effect (e.g. Flange) receives signals from the left input and the other effect (e.g. Delay) receives signals from the right input. However, both effects send signals to the left and right outputs. Dual Mono This bank contains programs that are arranged in the Dual Mono configuration. One effect (e.g. Flange) receives input from the left channel only and sends output to the left channel only. The other effect (e.g. Delay) receives input from the right channel only and sends output to the right channel only.

Chorus

DLY-RVB
Dly-Rvb Programs 150 Tap Small 151 3plTap MidSz 152 8+3pl Large 153 Pong Small 154 Xfeed MidSz 155 Xfeed Large 156 Tap > Room 157 8+3pl >Large 158 Xfeed > Room 159 Xfeed >Large "Adjust" (MidRT) (MidRT) (MidRT) (Decay) (Decay) (Decay) (Livenes) (MidRT) (Livenes) (MidRT) Tap Delay Time Delay Time Delay Time Delay Time Delay Time Delay Time Delay Time Delay Time Delay Time Delay Time Routing Dual Stereo (Parallel) Dual Stereo (Parallel) Dual Stereo (Parallel) Dual Stereo (Parallel) Dual Stereo (Parallel) Dual Stereo (Parallel) Cascade Cascade Cascade Cascade

Reverb

FLNG-RVB
Flng-Rvb Programs 160 LiteFl Small 161 LiteFl MidSz 162 LiteFl Large 163 DeepFl Small 164 DeepFl MidSz 165 DeepFl Large 166 LiteFl>Small 167 LiteFl >Room 168 DeepFl>Large 169 DeepFl >Room "Adjust" (MidRT) (MidRT) (MidRT) (MidRT) (MidRT) (MidRT) (MidRT) (Livenes) (MidRT) (Livenes) Tap Speed (Whole Note) Speed (Whole Note) Speed (Whole Note) Speed (Whole Note) Routing

PCH-RVB

Pch-Rvb Programs 170 3rd4th Room 171 4th5th Room 172 5th6th Room 173 8ve MidSiz 174 Power MidSiz 175 Detune Room 176 Fine > Small 177 Power >Large 178 4th > MidSiz 179 8ve > MidSz "Adjust" (Pitch) (Pitch) (Pitch) (Pitch) (MidRT) (Dtuning) (Pitch) (MidRT) (MidRT) (MidRT) Tap Routing Dual Stereo (Parallel) Dual Stereo (Parallel) Dual Stereo (Parallel) Dual Stereo (Parallel) Dual Stereo (Parallel) Dual Stereo (Parallel) Cascade Cascade Cascade Cascade

CHOR-RVB

Chor-Rvb Programs 180 Chor1 Small 181 Chor1 MidSiz 182 Chor1 Large 183 Chor2 Small 184 Chor2 MidSiz 185 Chor2 Large 186 Chor1 > Room 187 Chor2 > Room 188 Chor3 > Room 189 Chor1 >Small "Adjust" (MidRT) (MidRT) (MidRT) (MidRT) (MidRT) (MidRT) (Livenes) (Livenes) (Livenes) (MidRT) Tap Routing

MSPLIT DLY

MSplit Dly Programs 190 Flng + Tap 191 Flng + Pong 192 Flng + Xfeed 193 Flng + Bnce 194 DeepFl + Dly 195 5th + Tap 196 8ve + 3plTap 197 4th5th+Xfeed 198 5th6th+Xfeed 199 PchFine +Tap 200 Chor + Tap 201 Chor + Pong 202 Chor + Xfeed 203 Chor + Bnce 204 Chor+Inverse "Adjust" (FeedBk) (FeedBk) (Time) (Time) (Time) (Pitch) (Pitch) (Pitch) (Pitch) (Pitch) (FeedBk) (FeedBk) (Time) (Time) (Time) Tap 1/4 Note 1/4 Note Delay Time Delay Time Delay Time Delay Time Delay Time Delay Time Delay Time Routing Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split
Note: The Mono Split routing configuration is illustrated on page 4-18.

MSPLIT RVB

MSplit Rvb Programs 205 Tap + MidSiz 206 Pong + Large 207 Bnce + MidSz 208 Xfeed + Small 209 Xfeed+MidSiz 210 LiteFl+MidSz 211 LiteFl+Large 212 DeepFl+Small 213 DeepFl+MidSz 214 DeepFl +Room 215 4th5th +Room 216 5th6th +Room 217 4ths + Large 218 8ve + MidSz 219 PchFin+MidSz 220 Chor1 +Small 4-28 "Adjust" (MidRT) (MidRT) (MidRT) (MidRT) (MidRT) (MidRT) (MidRT) (MidRT) (MidRT) (Livenes) (Pitch) (Pitch) (MidRT) (MidRT) (Pitch) (MidRT) Tap Delay Time Delay Time Delay Time Delay Time Delay Time Routing Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split
MSplit Rvb Programs 221 Chor1+ Large 222 Chor2+MidSiz 223 Chor2+ Large 224 Chor3+MidSiz
"Adjust" (MidRT) (MidRT) (MidRT) (MidRT)
Routing Mono Split Mono Split Mono Split Mono Split

DUAL MONO

Dual Mono Programs 225 Tap | Small 226 Tap | MidSiz 227 Tap | Large 228 Tap | Room 229 DeepFl | Tap 230 DeepFl | Dot8ves | Tap 232 8ves | 3pl 233 Chor2 | Tap 234 Chor2 | DotLiteFl | Large 236 DeepFl | Large 237 8ves | MidSz 238 4ths | Large 239 Chor1 | Room "Adjust" (MidRT) (MidRT) (MidRT) (Livenes) (FeedBk) (FeedBk) (Pitch) (Pitch) (FeedBk) (FeedBk) (MidRT) (MidRT) (MidRT) (MidRT) (Livenes) Tap Delay Time Delay Time Delay Time Delay Time Speed (1/4 Note) Speed (Dotted 1/4 Note) Delay Time Delay Time Delay Time Delay Time Speed Routing Dual Mono Dual Mono Dual Mono Dual Mono Dual Mono Dual Mono Dual Mono Dual Mono Dual Mono Dual Mono Dual Mono Dual Mono Dual Mono Dual Mono Dual Mono
Note: The Dual Mono routing configuration is illustrated on page 4-18.
Comprssr Programs 240 Two to One 241 Three to One 242 3:1 Small 243 5:1 Medium 244 3:1 Large 245 GuitarComp 246 Limiter 247 Male Vocal 248 Female Vocal "Adjust" (Gain) (Gain) (Gain) (Gain) (Gain) (Gain) (Gain) (Gain) (Gain) Tap PreDelay PreDelay PreDelay PreDelay PreDelay

CMPRSSR

In all Cmprssr programs, the "Adjust" parameter controls gain within a range of 0 to 9.5dB. It can be used to match volume levels between the dry, bypassed, and compressed output obtained with typical music material. If the System Mode parameter Mix Mode is set to Program, the Mix parameter will automatically be set to Wet, allowing the compressed delay signal to be the only output signal present. If the System Mode parameter Mix Mode is set to Global, the Mix parameter must be set manually. The five compressor-reverb presets offer a reverb component in parallel with a zero-delay dry component. The compressor acts on both. The Mix parameter should be set to Wet, and the effective mix should be adjusted with the Efx Bal parameter.

Determines the level of gain reduction applied when the sound source rises above the compression threshold. It can be set in ratios of 1:1, 1.60:1, 2.00:1, 2.66:1, 3.20:1, 4.00:1, 5.33:1, 8.00:1 and 10:1. For each dB rise in input to the compressor, the ratio indicates the fraction of the dB rise in output. For example, when Ratio is set to 4.00:1, the output will rise 0.25dB for each dB rise in input to the compressor. Higher settings will result in more compression.
Determines how fast compression is reduced when sound sources fall below the compression threshold. Slower settings reduce compression gradually. Faster settings reduce compression more quickly, causing the level of the sound source to be tracked more closely.

. continued on page 4-34

TAPE SATURATION
Tape saturation emulates the sound of sources recorded on analog tapes and sources recorded digitally. Because of the natural peak saturation that occurs with analog tapes, sound sources recorded on them seem louder than the same sound sources recorded digitally. To use this effect, increase the Gain parameter setting. The amount of gain used is guided by both the output level meter and, more importantly, the ear. Gain levels that are too high can dramatically reduce the dynamic range of sound sources, possibly causing objectionable distortion - just like real tape. Gain (Min, 1 to 30, Max) Saturation Controls the amount of saturation.
Lexicon (Off, Modern, Vintage)

LEVEL METERS

Determines average output level. Lower settings prevent signal saturation. Higher settings reduce peaks within the sound source relative to the average level of the sound source, enabling the peak saturation block to reduce peak levels. The setting can be increased to its maximum level without causing digital overload. However, excessive peak saturation may distort the signal.
1. Output Level Meter Indicates output levels. The value indicates the maximum output level of the left or right channel, whichever is greater. The tick marks are placed in 3dB increments. The right most tick mark indicates 0dB or maximum output level.
MPX 550 2. Peak Expansion Meter Indicates the level of peaks above the peak expansion threshold. Low-level peaks are shown as one or two graduated bars. Slightly higher peaks of longer duration are shown as three graduated bars. High-level peaks are shown as three solid bars. 4. Input Meter

32 to 104F (0 to 40C) 95% non-condensing
RFI/ESD FCC Class B European EMC Directive 89/336/ECC
Specifications are subject to change without notice.
DECLARATION OF CONFORMITY
Application of Council Directive(s): Standard(s) to which Conformity is Declared: Manufacturer:
73/23/EEC, 89/336/EEC, and 93/68/EEC EN 55103-1, EN 55103-2, and EN 60065: 1998 Lexicon, Inc., 3 Oak Park, Bedford, MA 01730-1441 USA The equipment identified here conforms to the Directive(s) and Standard(s) specified above. Dual Channel Processor Lexicon MPX 550 February 2002 Lexicon, Inc. Vice President of Engineering 3 Oak Park Bedford, MA 01730-1441 USA Tel: 781-280-0300 Fax: 781-280-0490 A-3
Type of Equipment: Model: Date:
Adjust Parameter.2-3, 5-4 AC Input Connector.1-8 Ambience Programs.4-6 ANALOG INPUTs.1-9 ANALOG OUTPUTs.1-9 Attack Parameter.4-33 (Dynamics), 5-4 Audio Levels, Setting.1-12 Audio Tap.2-6 to 2-7 Auto Load Parameter*.3-7 Balance Parameter.5-4 Bank Name Indicator.1-7 BassMult Parameter.5-4 BassXvr Parameter.5-4 Bypass Button.1-5, 2-7, 6-4, 6-5 Bypass Mode Parameter*.2-7, 3-5 Cascade Configuration.4-18, 4-19 CD-ROM, About the.ix to xiv Chamber Programs.4-5

* System Mode Parameters

Chor-Dly Programs.4-18, 4-22 Chor-Rvb Programs.4-18, 4-26 Chorus Programs.4-10 Clear User Bank.3-9 Clock Source Parameter*.3-4 CmpAttk Parameter.2-5, 5-4 CmpRatio Parameter.2-5, 5-4 CmpRels Parameter.2-5, 5-5 Cmprssr Programs.4-31 Compression (Dynamics).4-33 Compressor.2-5 Compressor Mode Parameter*.3-5 Configuration, Routing.1-7, 4-18 Connecting the Unit.1-10 to 1-11 Connectors, Rear Panel.1-8 to 1-11 Continuous Controllers.6-2, 6-4 to 6-5 Decay Parameter.5-2, 5-5 Declaration of Conformity.A-3
Delay Parameters.5-3 Depth Parameter.5-5 Detune Programs.4-12 Diffusion Parameter.5-5 Digital Output Parameter*.3-5 Display Brightness Parameter*.3-7 Dly Fbk Parmameter.5-5 Dly HiCut Parameter.5-5 Dly Lvl 1, 2, 3 Parameters.5-5 Dly Lvl Parameter.5-5 Dly XFbk Parameter.5-5 Dly/Eko Programs.4-14 to 4-15 Dly-Rvb Programs.4-18, 4-23 DlyTapLvl Parameter.5-6 Drum Dep Parameter.5-6 Drum Res Parameter.5-6 Dual Function Footswitch.1-10 Dual Mono Configuration.4-18
Dual Mono Programs.4-18, 4-30 Dual Programs.4-18 to 4-30 Dual Stereo (Parallel) Configuration.4-18 Dump Current Program.3-8, 6-7 Dump System Data.3-8. 6-7 Dump User Bank.3-8, 6-6 Duration Parameter.5-6 Dynamics.4-32 to 4-36 EDIT Knobs.1-5, 1-7, 2-3 Edit Pages Button.1-4, 2-3 Editing Programs.2-3 Efx Bal Parameter.4-19, 5-6 EkoDly L, R Parameters.5-6 EkoFbk L, R Parameters.5-6 ExpLvl Parameter (Dynamics).4-32 ExpThrsh Parameter (Dynamics).4-32 Factory Init.3-9 Flange Programs.4-11 Flng-Dly Programs.4-18, 4-20 Flng-Rvb Programs.4-18, 4-24 Footswitch Connector.1-8, 1-10 Front Panel.1-4 to 1-7 Front Panel Display.1-5, 1-6 to 1-7 Gain Parameter (Dynamics).4-34 Gain Reduction Meter (Dynamics).4-35 Gate/Inv Programs.4-3

Global Tempo.2-7 Hall Programs.4-4 HF Rlloff Parameter.5-2, 5-6 HighSlope Parameter.5-7 Horn Dep Parameter.5-7 Horn Res Parameter.5-7 Input Level Meters.1-6 Input Levels, Setting.1-12 Input Meter (Dynamics).4-35 Input Source Parameter*.3-4 Input Trim Knob.1-4 Input/OVL Indicator.1-6 to 1-7 Inputs, Rear Panel.1-8 to 1-11 Inspection Instructions.ix to xiv Intrvl Parameter.5-7 L Dly 1, 2, 3 Parameters.5-7 Learn Mode.6-2 Level Meters (Dynamics).4-34 to 4-35 Level Parameter.5-3, 5-7 Limited Warranty.Inside Back Cover Live-FOH Programs.4-36 to 4-37 Load Button.1-5, 2-2, 2-3 Loading Programs.2-2, 6-3 LowSlope Parameter.5-7 Mastering Dynamics.4-32 to 4-36 Matching Rhythm.2-6 Memory Protect Parameter*.3-7 Messages, Front Panel Display.1-7 Meters Parameter (Dynamics).4-33 MIDI Channel Assignment.6-2 MIDI Channel Parameter*.3-6, 6-2 MIDI Clock.6-6 MIDI Clock Parameter*.3-6, 6-6 MIDI Dumps.3-3, 3-8, 6-6 to 6-7 MIDI Implementation Chart.6-8 to 6-9 MIDI IN Connector.1-8 MIDI Learn Mode.6-2 MIDI OUT/THRU Connector.1-8 MIDI Out/Thru Parameter*.3-6, 6-7 MIDI Patches Parameter*.3-6 MIDI Program Banks.6-3 MIDI Program Change Parameter*.3-6 Mix Mode Parameter*.3-5 Mix Parameter.5-3, 5-8 Mono Split Configuration.4-18 MPX 550, About the.1-2 to 1-3 MSplit Dly Programs.4-18, 4-27 MSplit Rvb Programs.4-18, 4-28 to 4-29 MstrRate Parameter.5-8 Operating Mode Parameter*.3-6 to 3-7 Output Level Meter (Dynamics).4-34 Output Level Parameter*.3-4
Output Levels, Setting.1-12 Outputs, Rear Panel.1-8 to 1-11 OVL Indicator.1-6 to 1-7 Parallel (Dual Stereo) Configuration.4-18 Parameter Glossary.5-4 to 5-11 Parameter Graphics.5-2 to 5-3 Parameters, Dynamics.4-32 to 4-34 Parameters, System Mode.3-2 to 3-7 Pch (R), (L/S) Parameter.5-8 Pch Fbk (L), (R) Parameters.5-8 Pch-Dly Programs.4-18, 4-19, 4-21 Pch-Rvb Programs.4-18, 4-25 PDly (L), (R) Parameters.5-8 Peak Expansion (Dynamics).4-32 to 4-33 Peak Expansion Meter (Dynamics).4-35 Phase Parameter.5-8 Pitch Programs.4-13 Pitch Shift.4-19 Plate Programs.4-2 Power Switch.1-5 PreDelay Parameter.5-8 Program Banks, MIDI.6-3 Program Change Messages.6-2, 6-3 to 6-4 Program Descriptions.4-1 to 4-37 PROGRAM Knob.1-5, 2-2, 2-4 Program Load Mode Parameter*.3-5
Program Name.1-7 Program Number.1-7 R Dly 1, 2, 3 Parameters.5-9 Rate Parameter.5-9 Ratio Parameter (Dynamics).4-33 Rear Panel.1-8 to 1-9 Release Parameter (Dynamics).4-33 Res 1, 2 Parameters.5-9 Resonanc Parameter.5-9 Restore Default Commands.3-3, 3-9 Room Programs.4-7 Rotary Programs.4-9 Routing Configuration.1-7, 4-18 Rt HC Parameter.5-9 RvbLvl Parameter.5-9 S/PDIF Connectors.1-9 Safety Instructions.Inside Front Cover, iv to viii, ix to xiv Saturation Parameter (Dynamics).4-34 Selecting Programs.2-2 Setting Audio Levels.1-12 Shape Parameter.5-9 Single Programs.4-2 to 4-15 Size Parameter.5-9 Special FX Programs.4-16 to 4-17 Specifications.A-2 Speed Parameter.5-10 Speed 1, 2 Parameters.5-10 Spread Parameter.5-10 Stereo Stage Program.4-17 Store Button.1-5, 2-4, 6-2 Storing Programs.2-4 Sweep Parameter.5-10 Sweep 1, 2 Parameters.5-10 Sysex Messages.6-7 System Button.1-4, 3-2 System Mode.3-2 to 3-9 System Mode Parameters.3-2 to 3-7 Table of Contents.ii to iii Tap/Cancel Button.1-5, 2-4, 2-6 to 2-7, 6-2, 6-4, 6-5 Tap Tempo.1-7, 2-6 to 2-7 Tape Saturation (Dynamics).4-34 Tempo Mode Parameter*.2-7, 3-5 Thresh Parameter (Dynamics).4-33 Threshld Parameter.2-5, 5-10 Tremolo Programs.4-8 Tune 1, 2 Parameters.5-10 Unpacking Instructions.ix to xiv Warranty.Inside Back Cover Wavform Parameter.5-11 Width Parameter.5-3, 5-11

Chorus

DLY-RVB
Programmi di Dly-Rvb 150 Tap Small 151 3plTap MidSz 152 8+3pl Large 153 Pong Small 154 Xfeed MidSz 155 Xfeed Large 156 Tap > Room 157 8+3pl >Large 158 Xfeed > Room 159 Xfeed >Large "Adjust" (MidRT) (MidRT) (MidRT) (Decay) (Decay) (Decay) (Livenes) (MidRT) (Livenes) (MidRT) Tap Delay Time Delay Time Delay Time Delay Time Delay Time Delay Time Delay Time Delay Time Delay Time Delay Time Routing Dual Stereo (Parallel) Dual Stereo (Parallel) Dual Stereo (Parallel) Dual Stereo (Parallel) Dual Stereo (Parallel) Dual Stereo (Parallel) Cascade Cascade Cascade Cascade

Reverb

FLNG-RVB
Programmi di Flng-Rvb 160 LiteFl Small 161 LiteFl MidSz 162 LiteFl Large 163 DeepFl Small 164 DeepFl MidSz 165 DeepFl Large 166 LiteFl>Small 167 LiteFl >Room 168 DeepFl>Large 169 DeepFl >Room "Adjust" (MidRT) (MidRT) (MidRT) (MidRT) (MidRT) (MidRT) (MidRT) (Livenes) (MidRT) (Livenes) Tap Speed (Whole Note) Speed (Whole Note) Speed (Whole Note) Speed (Whole Note) Routing

PCH-RVB

Programmi di Pch-Rvb 170 3rd4th Room 171 4th5th Room 172 5th6th Room 173 8ve MidSiz 174 Power MidSiz 175 Detune Room 176 Fine > Small 177 Power >Large 178 4th > MidSiz 179 8ve > MidSz "Adjust" (Pitch) (Pitch) (Pitch) (Pitch) (MidRT) (Dtuning) (Pitch) (MidRT) (MidRT) (MidRT) Tap Routing Dual Stereo (Parallel) Dual Stereo (Parallel) Dual Stereo (Parallel) Dual Stereo (Parallel) Dual Stereo (Parallel) Dual Stereo (Parallel) Cascade Cascade Cascade Cascade

CHOR-RVB

Programmi di Chor-Rvb 180 Chor1 Small 181 Chor1 MidSiz 182 Chor1 Large 183 Chor2 Small 184 Chor2 MidSiz 185 Chor2 Large 186 Chor1 > Room 187 Chor2 > Room 188 Chor3 > Room 189 Chor1 >Small "Adjust" (MidRT) (MidRT) (MidRT) (MidRT) (MidRT) (MidRT) (Livenes) (Livenes) (Livenes) (MidRT) Tap Routing

MSPLIT DLY

Programmi di MSplit Dly 190 Flng + Tap 191 Flng + Pong 192 Flng + Xfeed 193 Flng + Bnce 194 DeepFl + Dly 195 5th + Tap 196 8ve + 3plTap 197 4th5th+Xfeed 198 5th6th+Xfeed 199 PchFine +Tap 200 Chor + Tap 201 Chor + Pong 202 Chor + Xfeed 203 Chor + Bnce 204 Chor+Inverse "Adjust" (FeedBk) (FeedBk) (Time) (Time) (Time) (Pitch) (Pitch) (Pitch) (Pitch) (Pitch) (FeedBk) (FeedBk) (Time) (Time) (Time) Tap 1/4 Note 1/4 Note Delay Time Delay Time Delay Time Delay Time Delay Time Delay Time Delay Time Routing Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split Mono Split

Lexicon, Inc 3 Oak Park Bedford, MA 01730-1441 USA Tel 781-280-0300 Fax.781-280-0490 www.lexicon.com Customer Support Tel 781-280-0300 Fax.781-280-0495 (Sales) Fax.781-280-0499 (Service)
Lexicon, Inc 3 Oak Park Bedford, MA 01730-1441 USA Tel 781-280-0300 Fax 781-280-0490 www.lexicon.com Customer Support Tel 781-280-0300 Fax 781-280-0495 (Sales) Fax 781-280-0499 (Service)

Dry Tracks

This card lists the dry tracks included on the CD-ROM enclosed with this user guide.
Percussion 2 Bass Drum. 3 Snare Drum 1. 4 Snare Drum 2. 5 Stick. 6 Shaker. 7 Claps. 8 Conga. 9 Table & Udo. 10 Percussion 1. 11 Percussion 2. 12 Open Drum Kit. 13 Funk Drum Kit. 14 Fusion Drums & Bass 15 Funk Drums & Bass. 16 Fusion Drums & Bass 17 Broadband Click. 18 Narrowband Click.
.(0:30).(0:46).(0:38).(0:38).(0:39).(0:41).(0:48).(0:54).(1:00).(1:23).(1:16).(1:08).(0:33).(0:33).(1:18).(0:38).(0:38)
Guitar 19 Acoustic Chords 1. 20 Acoustic Chords 2. 21 Acoustic Chords 3. 22 Acoustic Leads. 23 Acoustic Stops. 24 Electric Solo. 25 Electric Clean & Fast 26 Electric Dirty. 27 Electric Crunch.
.(0:59).(2:13).(1:12).(0:41).(0:36).(0:44).(0:32).(1:24).(0:38)
Bass 28 Slap (120 bpm).(1:29) 29 Fingered (120 bpm).(0:49)

WARNING

Do not play Track 1 on an audio CD player. It contains the computer portion of the disc and will emit fullscale digital noise.
Voice 30 Female Vocal Female Vocal Female Vocal Male Vocal 1. 34 Male Vocal 2. 35 Vocal Group 1. 36 Vocal Group 2.
.(0:43).(0:56).(0:20).(1:20).(0:21).(0:26).(0:28)
Dual Mono (Left/Right) 46 Kick/Snare. 47 Kick/Bass. 48 African Bell/Slit Drum 49 Acoustic Guitar/Vocal 50 Electric Guitar/Vocal. 51 Church Guitars. 52 Ms. Pride/Xavier. Post 53 Ambulance. 54 Motorcycle. 55 Street Noise. 56 Propeller Place 57 Jet Airplane. 58 Pipe Band. 59 TV Music. 60 Monologue.
.(0:30).(0:37).(0:43).(0:23).(1:31).(0:36).(1:04)
Keyboard 37 Hammond 1.(0:12) 38 Hammond 2.(0:07) 39 Rhodes.(0:59) Horns 40 Horn Section Horn Section Sax Solo. 43 Tenor Sax Solo.
.(1:23).(1:36).(0:30).(2:21)
.(0:19).(1:08).(1:00).(0:58).(1:02).(1:20).(0:18).(1:06)
TOTAL TIME.(54:31) Miscellaneous 44 Flute Solo.(0:24) 45 Accordian Solo.(0:35)