Lexicon LDD-1 Owner's Manual

LDD-1

AC-3/RF Demodulator

User Guide

Unpacking and Inspection

Save all packing materials in case you ever need to ship the unit. 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.

Precautions

Save these instructions for later use.
Follow all instructions and warnings marked on the unit.
Always use with the correct line voltage. Refer to the manufacturer's operating instructions for power requirements. Be advised that different operating voltages may require the

use of a different line cord and/or attachment plug.
Do not install the unit in an unventilated rack, or directly above heat producing equipment such as power amplifiers. Observe the maximum ambient operating temperature listed

in the product specification.
Slots and openings on the case are provided for ventilation; to ensure reliable operation and prevent it from overheating, these openings must not be blocked or covered. Never

push objects of any kind through any of the ventilation slots. Never spill a liquid of any kind on the unit.
This product is equipped with a 3-wire grounding type plug. This is a safety feature and should not be defeated.
To prevent shock or fire hazard, do not expose the unit to rain or moisture, or operate it where it will be exposed to water.
Do not attempt to operate the unit if it has been dropped, damaged, exposed to liquids, or if it exhibits a distinct change in performance indicating the need for service.
This unit should only be opened by qualified service personnel. Removing covers will expose you to hazardous voltages.

This triangle, which appears on your
component, alerts you to the pres­ence of uninsulated, dangerous volt­age inside the enclosure... voltage
that may be sufficient to constitute a
risk of shock.

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

This triangle, which appears on your
component, alerts you to important
operating and maintenance instruc­tions in this accompanying litera­ture.

Acknowledgements

The CP and DC Series are manufactured under license from Dolby Laboratories Licensing Corporation. Additionally licensed under one or more of the following patents: U.S.
numbers 3,632,886, 3,746,792 and 3,959,590; Canadian numbers 1,004,603 and 1,037,877. "Dolby" and the double-D symbol are trademarks of Dolby Laboratories Licensing
Corporation.

Copyright 1997 Lexicon, Inc.
All Rights Reserved.

Lexicon Inc. • 3 Oak Park • Bedford MA 01730-1441

Telephone [phone] • Fax [phone]

Lexicon Part # 070-11659 Rev 1

LDD-1

AC-3/RF Demodulator

Congratulations on your purchase of the Lexicon LDD-1. The LDD-1 is designed to interface between
a laser disc player (with an AC-3/RF output), and any Dolby Digital decoder which accepts a standard
AC-3 signal (like our DC-1). Because “AC-3 ready” laser disc players use a separate Radio Frequency
(RF) modulated output to carry the Dolby Digital information, special considerations must be made.
While this type of transmission works perfectly well, our engineers were rightfully reluctant to inject line­level RF directly into the meticulously designed DC-1. The solution is the LDD-1.

The LDD-1 keeps potential RF interference away from the sensitive preamp/processor stage while
providing highly useful improvements in AC-3 signal quality. By placing the requisite demodulation
circuitry in its own enclosure with dedicated power supplies and grounding, the potential to degrade
digital-to-analog conversion and analog audio signals within the preamp/processor is eliminated.

The LDD-1 incorporates fully automated “intelligent” switching between S/PDIF and AC-3/RF inputs,
meaning that any laser disc will be decoded to its maximum inherent quality. A low voltage “turn on
trigger” input and output are included for interconnection to the Lexicon DC-1 and NT Series Amplifiers.
The stringently designed outboard power supply ensures maximum signal purity.

We have designed this manual to provide a brief overview of the demodulator, as well as to provide the
information necessary for safe installation and operation. We trust that the time you invest in reviewing
these brief instructions will be rewarded by the best possible performance and longevity of your
equipment.

User Guide

Introduction

1

NOTE: When power is off, the LDD-1 automatically
outputs the COAXial digital input.

LOCK

This LED will light whenever the unit

POWER

This LED will light whenever power to
the unit is supplied and enabled.

senses an AC-3/RF signal. When no such
signal is present, the LED will remain off,
and the INPUT SELECT LED will light.

Front Panel

2

LD OPTIMIZATION

3-position switch which minimizes signal errors, pro­viding optimal timing for specific brands of laser disc
players.

Recommended Settings

High Panasonic, Pioneer CLD-97 (MSB modified

Low Denon, Enlightened Audio Designs, Pioneer

Normal Marantz, Mitsubishi, McIntosh, MSB, Theta,

version), Runco

LD-S2 (MSB modified version)

Pioneer (including Elite), Yamaha

INPUT SELECT

2-position switch for selection of the type of NON-AC-3/
RF digital output you are using from your laser disc
player.

2

Connections between the LDD-1 and associated

equipment should be made with all units UNPLUGGED!

RF IN

Connect this input to the laserdisc player’s RF/AC-3
output with a 75Ω coaxial cable. Keep this cable as

POWER

short as possible to minimize RF interference.

Connect the AC adapter here. Use only the supplied Lexicon
MSA AC adapter.

Rear Panel

OUTPUT

Connect this S/PDIF output to DC-1 digital input COAX1
with a 75Ω coaxial cable.

INPUT

Connect a 5-pin DIN cord (not supplied)
from this input to the DC-1 PWR CTL
Output. This allows the LDD-1 to power on
and off with the DC-1. If nothing is hooked
up here, the unit will turn on whenever the
AC adapter is supplied power. This set-up
allows use of a switched outlet or continu­ous power. (As power consumption and
heat generation are both minimal, this will
not harm the LDD-1.)

LOOP THRU

Allows the hook-up and power cycling of addi­tional components such as the Lexicon NT
Series of power amplifiers. Refer to the DIN
configuration diagram below.

1 = Ground
2 = Ground
3 = Power On (constant

when the DC-1 is On)
4 = Unused
5 = Trigger (programmable)

3

S/PDIF INPUTS

Connect this input to the laserdisc player’s NON-AC-3 digital
output using the appropriate 75Ω coaxial cable.

Because you can switch between these inputs from the front
panel, you may use both; which gives you an extra digital
input.

4

The LDD-1 chassis is barely four inches deep to allow it to be positioned adjacent to an AC-3-capable
player’s RF output. This minimizes the required RF-signal cable length to reduce any RF interference.
As the unit uses automated switching, and draws very little power, you can literally set it and forget it.

To set up the LDD-1:

• Connect a 75Ω coaxial cable between the LDD-1 rear panel RF (AC-3) input and the laser disc
player's RF/AC-3 output. Keep this cable as short as possible to minimize RF interference.

• Connect a 75Ω coaxial (or optical) cable between the LDD-1 S/PDIF input and the laser disc
player's digital output.

• Connect a 75Ω coaxial cable betwen the LDD-1 S/PDIF output and the DC-1 COAX 1 digital input.

• Recommended: Connect a 5-pin DIN cord (not supplied) between the LDD-1 PWR CTL input and
the DC-1 PWR CTL output. This allows the LDD-1 to power on and off with the DC-1. If this
connection is not made, the LDD-1 will turn on whenever its AC adapter is supplied power.

• Optional: Connect any additional components which allow remote turn on (such as Lexicon's NT
Series of power amplifiers) to the LDD-1 rear panel PWR CTL (LOOP THRU) connector.

• Connect the AC adapter provided to the POWER jack.

Once the LDD-1 is properly connected, set the front panel INPUT SELECT switch for the appropriate
type of NON-AC-3/RF digital output you are using on your laser disc player. (Most laser disc players
have only one.) Set the LD OPTIMIZATION switch according to the chart provided on page 2. Once you
have completed the connections and setting of the front panel switches, all functions are performed
automatically. LEDs on the front panel are provided to identify the operational state.

Setup

The LDD-1 requires no maintenance. However, it is good electrical practice to clean all connectors once
a year. Clean the exterior surfaces of the unit with a soft, lint-free cloth, dampened with warm water.

5

Maintenance

Specifications

Outputs One (1) Digital via COAX

Optimization 3-position toggle switch, decoder pulse settings

Controls and Indicators LEDs indicate operational status

Connectors Inputs: 4: 2 RCA (COAX); 1 TOSLINK (Optical); 1 5-pin DIN (PWR CTL)

General Dimensions: 17.0"X x 1.75"H x 4"D

Lexicon Inc.
3 Oak Park
Bedford MA 01730-1441
Telephone [phone]
Fax [phone]

Inputs 2: 1AC-3/RF via COAX; 2 Digital (1 COAX; 1 Optical)

Toggle switches for: LD Optimization: High, Low, Normal; Input Select: Optical, COAX

Outputs: 2: 1 RCA (COAX); 1 5-pin DIN (PWR CTL Thru)
Power connector: 2.5mm, 9VAC, 1A

Weight: 2.4 lbs net; 4.4 lbs shipping
Power Requirements: 120VAC, 60Hz or 230VAC, 50Hz. Use Lexicon MSA AC Power Adapter.

Rack mount adapters are available through your Lexicon dealer.

All specifications subject to change without notice.

Lexicon Part # 070-11659 Rev 1

Printed in U.S.A.