MPX 500

Release Notes
NEW SYSTEM MODE PARAMETER
R1-MPX 1 Mode has been added to the system parameter MIDI Program Change. This additional setting enables the MPX 500 to respond to program change messages from a Lexicon MPX R1 Foot Controller set to MPX 1 Mode. Parameter MIDI Program Change Settings Enabled, Disabled, R1-MPX1 Mode Default Setting Enabled
OVL INDICATOR SIGNALS DSP OVERLOAD
The OVL indicator located below the input meters reflects the internal processing state of the MPX 500, not clipping of the inputs. Intermittent flashing or constant lighting of this indicator signals the need to reduce input levels or the value of a parameter on the verge of feedback. Input overload is indicated on the meters themselves. When input clipping occurs on either channel, that channels meter changes to inverse video, signalling the need to reduce input levels. The diagram pictured at left shows clipping of the left channel as well as internal processing overload.
CHANGING SIZE AND DURATION PARAMETERS
Changing the Size parameter in Reverb and Ambience presets or the Duration parameter in Gate presets will cause the program to reload. The program must reload in order for the unit to execute the extensive audio re-routing associated with changing these parameters without producing unwanted noise. The System Mode parameter Program Load Mode determines whether the MPX 500 will mute or bypass during this reloading.

MEMORY PROTECT MODE

On page 19, the MPX 500 User Guide incorrectly states that Memory Protect Mode prevents changes to the User Bank or the System Parameters. When enabled, Memory Protect Mode does prevent changes to the User Bank. But it does not prevent changes to the System Parameters, nor does it prevent restoration of MPX 500 factory-default settings. This means that Factory Init will erase any stored programs in the User Bank.
A Harman International Company
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 Part No. 070-14117 | Rev 1 | 05/01

MPX 500 Release Notes

ADJUST KNOB ASSIGNMENTS

Lexicon

The User Guide lists incorrect Adjust knob assignments for some programs. Below is a list of these programs with their correct Adjust knob assignments: HiCut Inversion Time (0-400ms) + Feedback Time (200-1200ms) + Feedback Mid-band Reverb Time Mid-band Reverb Time Mid-band Reverb Time Mid-band Reverb Time
PARAMETERS PATCHED TO TEMPO
The Edit knobs cannot be used to adjust parameters patched to Tempo. Some MPX 500 programs link Tempo to certain parameters. In these programs, the message Patched to Tempo will appear on the display when changes to a patched parameter are attempted. Both the User Guide and the previous version of these Release Notes provide lists of programs that do not have Pre-delay patched to Tempo. Following is a complete and correct list of these programs: 3, 5, 6, 7, 63, 64, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 210, 215, 236, 237, 238. A Tempo patch was added to preset 12.
PROGRAM 114: STEREO STAGE
Program 114 is now Stereo Stage, designed to supply reverb while preserving stereo imaging in a live stage setup. Stereo imaging is preserved via time delay rather than conventional L/R panning so that a proper channel mix is maintained in both L and R speakers. To use this program, observe the following: Use the MPX 200 in-line between mixer and house amps, not as an effect that is mixed back into the main L and R signals. On your mixer, pan the input channel for each musician fully to that musicians side of the stage. Keep Mix set to 50% (the default setting when Program Load is set to Program). Adjust your Reverb level by changing the Balance parameter between full left (-50) and about -10. (Typical values should be between -45 and -40.) Set "Width" for the distance between the speakers at each side of the stage. The program loads with an assumed width of approximately 20 ft. The available range via the Adjust knob is 10-50 ft. These values assume that most audience members are seated within 30 degrees to either side of the stage centerline. If many audience members are seated further to the sides of the stage the Adjust setting can be increased, but otherwise it should be kept as low as possible. 2

MPX 500 Version 1.1 Software Upgrade
Installation Instructions & Release Notes
A Harman International Company
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 Part No. 070-14697 | Rev 0 | 06/01
2001 Lexicon, Inc. All rights reserved. This document should not be construed as a commitment on the part of Lexicon, Inc. The information it contains is subject to change without notice. Lexicon, Inc. assumes no responsibility for errors that may appear within this document.
Installation of the MPX 500 Version 1.1 Software Upgrade will reset the system configuration to factory-default settings. To preserve System Parameter settings and User Bank programs, perform the following steps: 1. Before installing the software upgrade, dump the System Parameters or the User Bank into an external MIDI device. (These are two separate dumps.) 2. Install the Version 1.1 software upgrade. 3. Send the previously saved System Parameter or User Bank dump back to the MPX 500.

WARNING

These service instructions are for use by qualified personnel only. Do not perform any servicing other than that contained in these instructions unless qualified to do so. Refer to safety summary prior to performing any service. 3

SAFETY SUMMARY

Lexicon
The following general safety precautions must be observed during all phases of operation, service, and repair of this instrument. Failure to comply with these precautions or with specific warnings elsewhere in these instructions violates safety standards of design manufacture and intended use of the instrument. Lexicon, Inc. assumes no liability for failure to comply with these requirements. GROUND THE INSTRUMENT To minimize shock hazard, the instrument chassis and cabinet must be connected to an electrical ground. The instrument is equipped with a 3-conductor AC power cable. The power cable must be either plugged into an approved 3-contact electrical outlet or used with a 3-contact to 2-contact adapter with the grounding wire (green) firmly connected to an electrical ground (safety ground) at the power outlet. The power jack and mating plug of the power cable meet International Electrotechnical Commission (IEC) safety standards. DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE Do not operate the instrument in the presence of flammable gasses or fumes. Operation of any electrical instrument in such an environment constitutes a definite safety hazard. KEEP AWAY FROM LIVE CIRCUITS Operating personnel must not remove instrument covers. Component replacement and internal adjustments must be made by qualified maintenance personnel. Do not replace components with power cable connected. Under certain conditions, dangerous voltages may exist even with the power cable removed. To avoid injuries, always disconnect power and discharge circuits before touching them. DO NOT SERVICE OR ADJUST ALONE Do not attempt internal service or adjustment unless another person capable of rendering first aid and resuscitation is present. DO NOT SUBSTITUTE PARTS OR MODIFY INSTRUMENT Because of the danger of introducing additional hazards, do not install substitute parts or perform any unauthorized modification to the instrument. DANGEROUS PROCEDURE WARNINGS Warnings such as the example below precede potentially dangerous procedures throughout this manual. Instructions contained in the warnings must be followed. Dangerous voltages capable of causing death are present in this instrument. Use extreme caution when handling, testing, and adjusting.

MPX 500 Version 1.1 Software SAFETY SYMBOLS
Following are symbols that appear throughout this user guide: Appears on the component to indicate the presence of uninsulated, dangerous voltage inside the enclosure voltage that may be sufficient to constitute a risk of shock. Appears on the component to indicate important operating and maintenance instructions in the accompanying literature.

CAUTION

ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS
The following practices minimize possible damage to EPROMs resulting from electrostatic discharge or improper insertion: Keep parts in original containers until ready for use. Avoid having plastic, vinyl, or styrofoam in the work area. Wear an anti-static wrist strap. Discharge personal static before handling devices. Remove and insert boards with care. When removing boards, handle only by non-conductive surfaces and never touch open-edge connectors except at a static-free workstation.* Minimize handling of EPROMs. Handle each EPROM by its body. Do not slide EPROMs or boards over any surface. Insert EPROMs with the proper orientation, and watch for bent pins on EPROMs. Use anti-static containers for handling and transport. To make a plastic-laminated workbench anti-static, wash with a solution of Lux liquid detergent, and allow to dry without rinsing.
Calls attention to a procedure, practice, condition, or the like that, if not correctly performed or adhered to, could result in injury or death.
Calls attention to a procedure, practice, condition, or the like that, if not correctly performed or adhered to, could result in damage to or destruction of part or all of the product.
Calls attention to information that is essential to highlight.
Lexicon This kit does not include two Phillips head screwdrivers (sizes 0 and 1) and a wrench or nut driver, which are also needed.
Turn off and disconnect all power to the unit prior to installing the software upgrade.
INSTALLATION INSTRUCTIONS
Performing this upgrade is an easy process. But to avoid problems, please follow these instructions carefully. Pay particular attention to the precautions listed in the safety summary, and those that appear throughout these instructions. Any damage caused during installation is not covered under warranty.

CONTENTS

This update kit includes: 1 MPX 500 EPROM 1 EPROM Extractor Tool Installation and Release Notes (this document) 1 Anti-static wrist strap
MPX 500 Version 1.1 Software
2. Carefully remove the side panels by pulling them out (as shown in the illustration below). Begin pulling at the end closest to the front panel.

STEP 1 - OPEN THE UNIT

1. Using a size 1 Phillips head screwdriver, remove the screws (Lexicon Part No. 640-02812) on the top and bottom of the unit (three on top, three on bottom).

Top View of Unit

Bottom View of Unit
3. Remove the screw (Lexicon Part No. 640-02812) and nut (Lexicon Part No. 643-01732) closest to the AC receptacle. This is the only screw with a nut attached.
Screw & Nut Inside the Unit Back 9 Larger Screws
4. Remove the nine larger screws (Lexicon Part No. 641-11466) on the rear panel.
INSTRUCTIONS (continued) STEP 1 - OPEN THE UNIT (continued)
5. Using a size 0 Phillips head screwdriver, remove the four smaller screws (Lexicon Part No. 641-12759) near the MIDI IN & OUT/THRU ports.
Lexicon 7. Remove the U-shaped chassis cover by gently pulling it straight back, away from the front panel.

4 Smaller Screws

8. Put the anti-static wrist strap on before proceeding to the next step.
6. Using a wrench or nut driver, remove the five plastic nuts (Lexicon Part No. 643-11682) attached to the 1/4 connectors.

5 Plastic Nuts

B. Hold the body of the EPROM and, exerting gentle pressure downward, roll it slightly to force the pins into a position parallel to the work surface (see diagram below).
STEP 2 - INSTALL THE EPROM
1. Refer to the illustration below to locate the EPROM on the MPX 500 main board (location U9).
3. Using the EPROM extractor tool (see diagram below) remove the EPROM at location U9 and insert the new EPROM in its place. Be careful to align the EPROM correctly to avoid bending any pins. When the EPROM is inserted, carefully inspect each pin to ensure that it has not been bent.
2. Check the EPROM provided with the upgrade kit. Because the manufacturing process leaves the pins angled out slightly from the body of the EPROM, the pins must be straightened before insertion. Use the following procedure to straighten the pins: A. Place the EPROM on its side on a static-free, flat surface.
INSTRUCTIONS (continued) Note: STEP 2 - INSTALL THE EPROM (continued)

EPROMs that are inserted incorrectly will likely be destroyed, and may also cause damage to the board.
To reassemble the unit, follow instructions 1-7 under the heading Step 1 - Open the Unit (pages 7-8) in reverse order.

RELEASE NOTES

This following describe the enhancements contained in the MPX 500 Version 1.1 Software Upgrade: The Tap button responds to consecutive rather than alternate presses.
MPX 500 Version 1.1 Software The program knob is less sensitive. Program Tempo now works for programs stored in the User Bank. Tempo-dependent programs stored in the User Bank are now retrieved properly, even if the sample rate has changed.
Paragraph four of the original Release Notes for the MPX 500 contained a list of presets from which the Tempo patch was removed after the original User Guide was prepared. That list had a few omissions. Following is a correct version: 3, 5, 6, 7, 63, 64, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 210, 215, 236, 237, 238. A Tempo patch was added to preset #12. Random clicking in Ambience programs has been fixed.

ERRATA NOTES

On page 19, the MPX 500 User Guide incorrectly states that Memory Protect Mode prevents changes to the User Bank or the System Parameters. When enabled, Memory Protect Mode does prevent changes to the User Bank. But it does not prevent changes to the System Parameters, nor does it prevent restoration of the MPX 500 factory-default settings. This means that Factory Init will erase any stored programs in the User Bank.