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 © 2002 Alesis. All rights reserved. Reproduction in whole or in part is prohibited. Change Without Notice. 7-51-0107-A 6/2002 Specifications Subject To 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. 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. CE Declaration of Conformity For the CE Declaration of Conformity, please visit the Alesis web site at: www.alesis.com · · A-2 EC-2 Manual appendix A · EC-2 96kHz A/D/D/A upgrade Installing the EC-2 into the HD24 Precautions 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. 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) 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 EC-2 96kHz A/D/D/A upgrade · appendix A Prepare to install: 1 . Disconnect the HD24's AC power cable, and make sure you are working on a clean, flat, hard surface. Ground yourself by touching a grounded metal object. An anti-static workstation with anti-static mat and wrist strap is highly recommended. Remove the existing converter PCBs and cables: 3. Locate the existing DC power cable. This cable has several thick red, orange, yellow, black, and blue wires bundled together. Pinch the tab lock holding the white connector to the back of Drive 1 and carefully disconnect it. Do the same for the connector on Drive 2, the Main PCB (the printed circuit board on the floor of the HD24), and finally the power supply itself. (This will be replaced with a new cable in step 14.) Hazardous voltages are present within the chassis. Do not remove the top panel without first unplugging the unit from AC power! 4 . Disconnect the 26-pin flexible ribbon cables from the existing converter PCBs and the main PCB, and remove them completely. New 26-pin cables are attached to the EC-2 daughterboard--the old ones will not be used. 5. Remove the 24 nuts and washers on the 1/4" input connectors, holding the PCB in place to keep it from falling. Then remove the old A/D PCB (the highest one on the back panel). 6. Do the same for the 24 nuts and washers on the 1/4" output connectors. Hold the PCB in place to prevent the D/A PCB from dropping onto the main PCB. Once the PCBs are removed, put the nuts and washers back on the jacks and store these PCBs and cables in the packaging that the EC2 came in. 2. Remove the cover from the HD24: The cover is held to the body with 5 Philips head screws on the rear, 2 on each side, and one on the top. Slide the cover directly towards the rear; don't lift it up--there are metal tabs on the back panel and along the bottom that will get bent if you do. HD24 interior with original A/D/A PCBs Main PCB A/D PCB D/A PCB Power supply DC power cable (remove) 26-pin ribbon cables (remove) Drive 1 Drive 2 A-4 EC-2 Manual appendix A · EC-2 96kHz A/D/D/A upgrade Install the new EC-2 PCBs 7. Find the daughterboard in the EC-2 package: it has two 26-pin flexible cables attached to it. Insert the ribbon connector labeled "J4 TO MAIN PCB" on the daughterboard into the 26pin header labeled on the main PCB as "J15 TO A/D PCB". NOTE: The Analog Input and Analog Output PCBs look very similar. Verify that you have the correct PCB by looking for the part number and part name in the text in the corner of the PCB. 11. Place the Analog Output PCB in the bottom set of rear panel holes (labeled OUTPUT on the rear panel) with the components facing down (so that you can read the white text on the PCB, which says "D/A PCB" and "Analog Output"). Put a few of the washers and nuts on the 1/4" jacks to hold the PCB in place. Screw them down all the way, but do not tighten yet--it should be just a little loose. 12. Place the Analog Input PCB in the top set of rear panel holes (labeled INPUT on the rear panel) with the components facing down and put a few of the washers and nuts on the 1/4" jacks to hold the PCB in place. Screw them down all the way, but do not tighten. 8 . Insert the ribbon connector labeled "J3 TO MAIN PCB" on the daughterboard into the 26pin header labeled on the main PCB as "J14 TO D/A PCB". The headers on the main PCB sit near the back center, where the old input/output PCBs used to plug in. The red side of each cable should face the right of the HD24 (closest to the fan). Verify that the cables don't have any twists in them and that there are no unconnected or exposed pins on the headers. 9. Lay the daughterboard gently on the PCBs at the rear of the hard drive cages until the Analog Input and Analog Output PCBs are installed. 10. Get the new Analog Output (D/A) PCB from its packaging. Remove the nuts and washers from the 1/4" connectors on the new Analog Output (D/A) PCB. HD24 with EC-2 installed Daughterboard PCB 1 Analog In A/D PCB 2 3 4 5 6 Analog Out D/A PCB New DC power cable EC-2 Manual A-5 EC-2 96kHz A/D/D/A upgrade · appendix A Connect the PCBs 13. Connect the daughterboard to the Input and Output PCBs: Line up the connectors to the bottom (D/A) and top (A/D) PCBs, make sure all the pins line up, then gently push the daughterboard to the rear of the HD24 using the plastic ribbon cable headers as pressure points, making a connection between all three PCBs. The connectors will only line up in one orientation. Verify that there are no pins unconnected or exposed. 14. Put the remainder of the washers and nuts on the jacks of the input and output connectors and tighten them all down (total 48 jacks). 15. Install the new DC power cable, connecting the power supply, main PCB, daughterboard, and hard drive PCBs as shown in the illustration on the previous page. Run it ...