Alesis EC2 User Manual

EC-2

96kHz Sample Rate Upgrade

A/D and D/A Converter Cards

for the ADAT HD24 Hard Disk Recorder

OWNER’S MANUAL

VERSION 1.0

APPLIES TO ADAT HD24 SOFTWARE VERSION 1.05 AND ABOVE

EC-2 96kHz A/D/D/A upgrade • appendix A

7-51-0107-A 6/2002

EC-2 Manual

appendix A

EC-2 96kHz Upgrade Cards

This document covers only those aspects unique to the EC-2 cards and should be kept with the HD24 manual.

Table of Contents

Important Safety Instructions ................................2

Safety symbols used in this product .......................2

CE Declaration of Conformity................................2

About the EC-2.....................................................2

Installing the EC-2 into the HD24...........................3

Using the EC-2 .....................................................6

Inputs and Outputs...............................................7

About the EC-2’s audio performance......................8

When to use 88.2/96 kHz ......................................8

Extending the frequency range of other studio

equipment.................................................... 10

Using the HD24/EC-2 with computer

workstations and digital mixers..................... 11

Using the HD24/EC-2 with the Alesis AI-4

AES/EBU Interface....................................... 12

Specifications ......................................................... 13

Index

12-channel operation................................................6

AES/EBU Digital Audio Interface........................... 12

Analog Input (A/D) board .......................................5

Analog Output (D/A) board ....................................5

Antialiasing filters ...................................................8

anti-static

during installation .............................................4

converters ...............................................................8

daughterboard ........................................................3

DC power cable....................................................... 6

Digital inputs and outputs

at high sample rates ...........................................6

digital mixers

at high sample rates ......................................... 11

dynamic range.........................................................8

Latency ................................................................. 11

level change

in unbalanced input...........................................7

low-pass filters ...................................................... 10

MasterLink

exporting to..................................................... 12

microphones ......................................................... 10

MIDI sequencer .......................................................2

mixing consoles..................................................... 10

monitors

at 96 kHz......................................................... 10

Nyquist theorem......................................................8

oversampling filters................................................. 9

phase response ........................................................9

sample rates

about ................................................................8

software

upgrade ............................................................2

Synchronizing .........................................................7

Word clock............................................................ 12

workstations.......................................................... 11

EC-2 Manual A-1

EC-2 96kHz A/D/D/A upgrade • appendix A

Important Safety Instructions

Safety symbols used in this product

This symbol alerts the user that there are

important operating and maintenance instructions in the literature accompanying this unit.

This symbol warns the user of uninsulated

voltage within the unit that can cause dangerous electric shocks.

All safety warnings in the HD24 manual (pages 7 through 10) apply to the EC-2 as well.

CE Declaration of Conformity

For the CE Declaration of Conformity, please visit the Alesis web site at: www.alesis.com

About the EC-2

The EC-2 is an optional 96kHz sampling rate analog hardware upgrade designed exclusively for the Alesis ADAT HD24. It provides 24 simultaneous channels of balanced +4 dBu analog audio inputs and outputs via 48 1/4” TRS type jacks. The EC-2 is installed directly inside the HD24’s rear panel, in place of the original A/D and D/A boards, for simple system integration and flexibility. With the EC-2 installed, the HD24 can record and play back digital audio at the 96kHz or 88.2 kHz sampling rates (in addition to the standard 44.1 and 48 kHz rates) via its analog inputs and outputs. In high sample rate mode, the HD24 can record and play back up to 12 tracks at a time.

The EC-2 expansion cards are designed for use only with HD24 software version 1.05 or higher. If your HD24 has a lower software version, visit our web site at www.alesis.com to download the latest HD24 software and instructions for updating the HD24 via a standard MIDI file or via Ethernet. If you don’t have a computer or MIDI sequencer, contact your Alesis dealer or local service center to help you with the upgrade.

The EC-2 upgrade boards are a replacement for the standard HD24 analog converter boards. They do everything the standard boards do, plus:

• 24 channels of High Performance 24-bit

Analog Audio Conversion. 24 channels of

simultaneous input and output on 1/4” TRS jacks. Superior DACs and ADCs allow the EC-2 to considerably surpass the standard converter boards in THD+N and dynamic range.

• Support for Sample Rates up to 96kHz. The EC-2 boards allow you to use analog inputs and outputs at 88.2kHz and 96kHz nominal sample rates.

• Simple hookup and operation. The EC-2 is designed to install in the rear panel of the HD24 and connects to the main circuit board with the included multi-pin ribbon connectors. Once connected, the HD24 will detect the cards’ presence, and allow you to select analog inputs as the source when using the 88.2kHz and 96kHz sample rates.

A-2 EC-2 Manual

Installing the EC-2 into the HD24

appendix A • EC-2 96kHz A/D/D/A upgrade

Precautions

The EC-2 boards should only be installed by a

dealer or trained technician. End users should only attempt installation if they have experience with this type of procedure. If any of the following instructions are not clear to you, please have a dealer or trained technician install it for you. Improper installation by the end user may damage the boards and/or your HD24 and may void your warranty.

Packing List

In the EC-2 box, you should find the following items:

• This manual (P/N 7-51-0107, E2 User’s Manual)

• 96 kHz Analog Input board (P/N 9-40-0256, E2

A/D PCB)

• 96 kHz Analog Output board (P/N 9-40-0257, E2 D/A PCB)

• Daughterboard (P/N 9-40-0258, E2 D/D PCB)

• DC power cable (P/N 4-74-0031, E2 DC Power

Cable)

Overview

In the HD24, the conversion between analog and digital signals takes place on two PCBs (printed circuit boards) that are mounted directly to the input (A/D) and output (D/A) connectors that poke through the back panel. In a “stock” HD24 without 96 kHz sampling capability, each card connects directly to the main PCB on the bottom of the unit with a ribbon cable.

To add 96kHz analog recording and playback capability, both the input and output boards are completely replaced, and another board (the daughterboard) is added bridging across them. The daughterboard then connects via ribbon cables to the main PCB. The daughterboard requires a connection to the power supply, so the existing 4connector power cable must be replaced with a new 5-connector power cable.

Tools required

Before you begin, have these tools ready:

• #2 Philips-head screwdriver

• 14 mm nut driver or socket wrench

Before you begin, verify that you have everything in this packing list. When you unwrap the components, save the packing materials so you can use them to store the original parts.

EC-2 Manual A-3

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