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dCS 974
Digital to Digital Converter
User Manual
Software version 1.0x
May 2001
© 2001 dCS Ltd
All rights reserved. Reproduction of this manual in any manner whatsoever,
1
without the written permission of dCS is strictly forbidden. Additional copies of
this manual may be obtained from dCS.
Information contained in this manual is subject to change without notice, and
whilst it is checked for accuracy, no liabilities can be accepted for errors.
Summary of the content on the page No. 2
dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 Manual part no: DOC1241121A1 Page 2 Document No: OS-MA-A0124-112.1A1 Contact dCS on + 44 1799 531 999 email to: more@dcsltd.co.uk (inside the UK replace + 44 with 0) web site: www.dcsltd.co.uk
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 PRODUCT OVERVIEW The dCS 974 DDC (Digital to Digital Converter) is a high performance real time sample rate and format converter, developed from our highly successful dCS 972. It is designed for studio applications where source material is available in one format, but outputs are required in other digital formats in real time. For example, archives might be made for storage in 24/192 or 24/176.4 formats, and then used to prod
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 Monitoring Bit Activity (page 56), Stereo Output Level (page 57), and CRC, Parity & Invalid flag errors in the input data (page 52). Test Generator High quality (160 dB) signal generator with mHz resolution (page 53). Can be dithered and/or noise shaped truncated. Ease of Use User programmable set-ups (page 61) Pre-loaded setups Remembers last settings Lockouts (page 64) Manual part no: DOC1241121A1 Page 4 Document No: OS-MA-A
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 About this Manual If you have not used a dCS 974 before, please read the section Using Your dCS 974 For The First Time on page 110. This manual has been arranged with the most commonly used sections placed first: • table of contents (page 6) • step-by-step (page 10) and applications guides (page 22) • detailed software and hardware information (page 34) • technical information (page 70) • information for first time users (page
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 CONTENTS Product Overview ...............................................................................................3 About this Manual 5 About Sample Rates 5 Contents ..............................................................................................................6 Step-by-Step Guide ..........................................................................................10 Preliminaries 10 Step 1 – Selecti
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 Noise Shaping 47 Dither 47 AES Message Edit 48 SPDIF Message Edit 48 Gain/Balance and Maximise 48 Swap Channels 49 Phase 49 Detect Silence 50 De/Pre-Emphasis 50 Display Customise 50 Error Monitor Submenu 52 Error Hold and Reset 52 Test Submenu 53 Generator Overview 53 Controlling the Generator 53 Generator Amplitude Adjustment 54 Generator Frequency Adjustment 54 Self Test 55 Info Submenu 56 Bit Activity Monitor Submenu 56 Bit
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 SDIF-2 Message Handling 90 SDIF-3 Message Handling 90 Power Consumption 91 Size, Weight and Operating Conditions 92 dCS 974 Performance Curves...........................................................................94 General Technical Information......................................................................104 Word Length Reduction 104 Using Your dCS 974 For The First Time ...........................................
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 Manual part no: DOC1241121A1 Page 9 Document No: OS-MA-A0124-112.1A1 Contact dCS on + 44 1799 531 999 email to: more@dcsltd.co.uk (inside the UK replace + 44 with 0) web site: www.dcsltd.co.uk
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 STEP-BY-STEP GUIDE This section guides you through setting up the unit for basic operation. You may find this useful if you have not used the dCS 974 for a while. Preliminaries The Quick Start Guide sheet details the menu structure and outlines the use of the front panel controls. For more information, see Navigating through the Menu – what the On-Screen symbols mean on page 36 and The Software – Menu and Setups on page 34. We
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 Step 1 – Selecting an Input TOP LEVEL Sample Rate Conversion Audio Input Select AES 1 Default Sync Source AES 2 Multi-Channel Sync AES 3 Input Sample Rate AES 4 Dual AES (1+2) Quad AES SPDIF1 (RCA) SPDIF2 (BNC SPDIF3 (TOS) PCM SDIF-2 DSD SDIF-2 DSD Quad Figure 1 – Audio Input Selection Choose one of the following five sections: Connecting to a Single AES or SPDIF source do this: Connect your source equipment to the matching in
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 Connecting to a Dual AES Source do this: Check that your source equipment is capable of Dual AES operation. do this: Connect the AES 1 (or AES A) output on your source equipment to the AES 1 input on the dCS 974 rear panel and the AES 2 (or AES B) output to the AES 2 input, using two XLR cables. Ensure the cables are not swapped. do this: Press the → → → → button twice to enter first the Sample Rate Conversion menu, then the A
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 Step 2 – Setting the Sync Source do this: Switch on the source equipment. If appropriate, load a disk / tape and set the machine in PLAY mode to ensure it is generating a digital audio data stream. The dCS 974 will be set to sync to the selected Audio Input and the Input Sample Rate will be Auto detected. The unit should lock and the Unlocked indicator should turn off. If you do not want to use an external reference clock, pro
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 Syncing to an AES/EBU Reference If you want to synchronise your system to an AES/EBU Reference from a Master Clock (such as the dCS 992) or other stable source, do the following: do this: Set the Master Clock sample rate to match the source (probably 44.1 or 48kS/s). do this: Connect either an AES/EBU or Wordclock output from the Master Clock to the clock input on the source equipment and ensure it is locked. do this: Connect
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 Step 3 - Setting a Conversion do this: If you need bit-for-bit operation in a different output format, proceed to the Format Conversion section. do this: If you want to change the sample rate or the word length or process the data in some other way, proceed to the Sample Rate Conversion section. Format Conversion TOP LEVEL Format Conversion Pure Format Conversion Off Default Audio Input Select On Sync Source Multi-Channel Sync
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 Sample Rate Conversion TOP LEVEL Sample Rate Conversion Audio Input Select 192kS/s Sync Source 176.4kS/s Multi-Channel Sync ... Input Sample Rate 12kS/s Output Sample Rate 11.025kS/s DSD Clock (DSD only) Output Mode Normal Default Filter Dual AES Quad AES DSD SDIF-2 DSD SDIF-3 Figure 4 – Sample Rate Conversion do this: If DSD output formats are required, proceed to Setting the Output Mode. Setting the Output Sample Rate do thi
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 Setting the Output mode do this: Scroll down the Sample Rate Conversion menu to Output Mode and press the → → button. The cursor should be beside Normal Choose one of the settings → → from the following list, scroll to it and press Set: • Normal. The Output Sample Rate must not be higher than 96kS/s. Single wire data will be available on all of the AES, SPDIF or SDIF-2 outputs. • Dual AES. The Output Sample Rate must be 88.2,
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 Step 4 – Connecting the Outputs Choose one of the following five sections: Connecting a Single AES or SPDIF Output do this: If the Output Sample Rate is 88.2 or 96kS/s, check that your destination equipment is capable of double speed operation. do this: If you have set Output Mode to Normal, connect the required single wire output on the dCS 974 rear panel to the matching inputs on the destination equipment using suitable cabl
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 Step 5 – Reducing the Output Wordlength If you are using Pure Format Conversion or DSD output modes, the Output Wordlength cannot be changed. Proceed to Other Settings. If you are performing a sample rate conversion with PCM outputs, the destination equipment can handle 24 bit data and you do not want to reduce the wordlength then leave the Output Wordlength set to the default of 24 bits and set Dither to Off. Proceed to Other
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dCS 974 User Manual Manual for Software Version 1.0x dCS Ltd May 2001 A wide variety of Noise Shaping and Dither setting combinations are possible. For more information, see Word Length Reduction on page 104. do this: Proceed to Other Settings. Manual part no: DOC1241121A1 Page 20 Document No: OS-MA-A0124-112.1A1 Contact dCS on + 44 1799 531 999 email to: more@dcsltd.co.uk (inside the UK replace + 44 with 0) web site: www.dcsltd.co.uk
