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, without the written permission of dCS1 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. 1 dCS Ltd is Data Conversion Systems Ltd.
dCS 974 User Manual dCS Ltd Manual part no: DOC1241121A1 Contact dCS on + 44 1799 531 999 (inside the UK replace + 44 with 0) Manual for Software Version 1.0x May 2001 Page 2 Document No: OS-MA-A0124-112.1A1 email to: more@dcsltd.co.uk web site: www.dcsltd.co.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x 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.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x 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.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x 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.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 CONTENTS Product Overview ...............................................................................................3 About this Manual About Sample Rates 5 5 Contents ..............................................................................................................6 Step-by-Step Guide ..........................................................................................
dCS 974 User Manual dCS Ltd Manual for Software Version 1.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 SDIF-2 Message Handling SDIF-3 Message Handling Power Consumption Size, Weight and Operating Conditions 90 90 91 92 dCS 974 Performance Curves...........................................................................94 General Technical Information......................................................................104 Word Length Reduction 104 Using Your dCS 974 For The First Time ..................................................
dCS 974 User Manual dCS Ltd Manual part no: DOC1241121A1 Contact dCS on + 44 1799 531 999 (inside the UK replace + 44 with 0) Manual for Software Version 1.0x May 2001 Page 9 Document No: OS-MA-A0124-112.1A1 email to: more@dcsltd.co.uk web site: www.dcsltd.co.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x 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.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x 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.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x 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.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x 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: do this: do this: do this: Set the Master Clock sample rate to match the source (probably 44.1 or 48kS/s). 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.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Step 3 - Setting a Conversion do this: do this: If you need bit-for-bit operation in a different output format, proceed to the Format Conversion section. 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.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Sample Rate Conversion TOP LEVEL Sample Rate Conversion Audio Input Select Sync Source Multi-Channel Sync Input Sample Rate Output Sample Rate DSD Clock (DSD only) Output Mode Filter 192kS/s 176.4kS/s ... 12kS/s 11.025kS/s Normal Dual AES Quad AES DSD SDIF-2 DSD SDIF-3 Default Figure 4 – Sample Rate Conversion do this: If DSD output formats are required, proceed to Setting the Output Mode.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Setting the Output mode do this: 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.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x 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 equipment is capable of double speed operation. do this: If you have set Output Mode to Normal, connect the required output on the dCS 974 rear panel to the matching inputs on the equipment using suitable cables.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x 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 Settings.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x 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 Contact dCS on + 44 1799 531 999 (inside the UK replace + 44 with 0) Page 20 Document No: OS-MA-A0124-112.1A1 email to: more@dcsltd.co.uk web site: www.dcsltd.co.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Other Settings The basic set-up procedure is complete. The Sample Rate Conversion menu contains several other menu pages. For more information, see Sample Rate Conversion / Format Conversion Submenu, starting on page 41. Manual part no: DOC1241121A1 Contact dCS on + 44 1799 531 999 (inside the UK replace + 44 with 0) Page 21 Document No: OS-MA-A0124-112.1A1 email to: more@dcsltd.co.uk web site: www.dcsltd.co.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 TYPICAL APPLICATIONS Converting a 24/96 recording to CD format From 24 bit / 96kS/s source AES / EBU INPUTS PUSH PUSH AES / EBU REFERENCE LOOP PUSH PUSH PUSH SPDIF IN CH1 IN CH2 IN REMOTE OUT IN WCLK IN LOOP OUT CH1 OUT CH2 OUT LOOP IN WCLK OUT AES 1 AES 2 AES 3 AES 4 AES CLK OUT OUT SYNC INPUT BNC DSD / SDIF RCA IN LOOP OUT MAINS FUSE (2AT) ON OFF TOS AES / EBU OUTPUTS 16 bit / 44.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Upsampling a CD DIGITAL OUT CLOCK IN L Hand Crafted by The Red Hot CD Player Co. R 16 bit / 44.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 General Sample Rate Conversion and Distribution From ANY format: AES, SPDIF, Toslink, SDIF-2 at ANY sample rate: 11.025k, 12k, 16k, 22.05k, 24k, 32k, 44.1k, 48k, 88.2k or 96kS/s or Dual AES at 88.2k, 96k, 176.4k or 192kS/s or Quad AES at 176.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 PCM to DSD From PCM in ANY format: AES, SPDIF, Toslink or SDIF-2 at sample rates: 44.1k, 48k, 88.2k or 96kS/s or Dual AES at 88.2k, 96k, 176.4k or 192kS/s or Quad AES at 176.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Using a Master Clock WORDCLOCK IN DIGITAL OUT L Hand Crafted by The Red Hot CD Player Co. R 16 bit / 44.1kS/s digital audio AES 3 AES 4 Wordclock Outputs AES 2 AES/EBU Outputs more@dcsltd.co.uk AES 1 44.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Converting Quad AES to CD Format 24 bit / 176.4kS/s Quad AES from 8-track recorder AES / EBU INPUTS PUSH PUSH Optional 44.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Multi-channel Sample Rate Conversion – Using a Master Clock AES 2 AES 3 AES 4 1 AES/EBU Outputs Wordclock Outputs AES 1 more@dcsltd.co.uk 44.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Multi-channel Sample Rate Conversion – with more alignment tolerance WORDCLOCKS TO SOURCES dCS 992 Master Clock AES 3 AES 4 1 Wordclock Outputs AES 2 AES/EBU Outputs more@dcsltd.co.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Multi-channel Sample Rate Conversion – with multiple sample rates out 6 A dCS 992 Master Clock can also be used to sync up the source and more than one set of units, all at different sample rates, and be the master. DVD production may require different sample rates for different channels – this set up will give real time 48 kS/s rear channels and 96 kS/s front channels from a multi-channel 44.1kS/s source. See Figure 16 overleaf.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 THE SOFTWARE – MENU AND SETUPS TOP LEVEL Sample Rate Conversion (SRC) / Format Conversion (FC) menu Audio Input Select Sync Source Multiple Channel Sync Audio Input AES Loop AES Loop Terminated Wordclock Internal Lab Ref (10MHz) Off On 192 kS/s 176.4 kS/s 96 kS/s 88.2 kS/s 50 kS/s 48 kS/s 44.1 kS/s 32 kS/s 24 kS/s 22.05 kS/s 16 kS/s 12 kS/s 11.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Navigating through the Menu – what the On-Screen symbols mean Once the unit has powered up and the Status screen is displayed, you can start navigating through the menu. This section explains how the keys operate, and what the various on-screen indications mean. To start, pressing either the ← or → button brings up the top level of the Menu: The symbol is the cursor and an indication that there are sub-menus available below this level.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 The cursor has changed to to indicate that the bottom level has been reached. Turning the rotary control will move the cursor up and down the list. to Now press the Set button to accept Gain and the cursor changes to indicate that this parameter (Gain) may now be adjusted using the rotary control. Turn the control either way and the Gain changes in 0.1dB steps.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Top Menu The top menu contains the major entries: - Sample Rate Conversion, Format Conversion, Error Monitoring, Test, Info, Bit Activity Monitors, Level Meters and Display – as follows: In many cases, the settings in one menu do not affect those in others. In other cases they do, and where this occurs the menu will automatically adjust to allow only valid options.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Format Conversion The default setting is SRC mode on, FC mode Off. To turn FC mode on, select Format Conversion and press →. The menu below will appear: Pressing Set will toggle the state from Off to On. The unit will check to see if the Output Sample Rate is the same as the Input Sample Rate, and if it is not it asks you to press Set to change the Output Sample Rate, or any other button to cancel the attempt to turn FC mode on.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Bit Activity Monitors This menu turns on bit activity monitors on the selected input signal, for use on the audio data – it can find out how many active bits you have coming in, or identify stuck bits in other equipment. This only works for PCM inputs – the entry disappears for DSD inputs. This feature does NOT monitor the units outputs. Level Meters Controls level metering of the output data.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Sample Rate Conversion / Format Conversion Submenu The Sample Rate Conversion menu is as follows: Audio Input Select Select the required input from the list and press Set. The Dual AES option requires that the Input Sample Rate be set to 192 kS/s, 176.4 kS/s, 96 kS/s or 88.2 kS/s. The Quad AES option requires that the Input Sample Rate be set to 192 kS/s or 176.4 kS/s.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Multiple Channel Sync This option is either On or Off. The unit uses the AES Ref Loop In as a sync link. When On, if the unit detects a sync signal into the AES Ref Loop In, it will sync to it and set up as a Slave. If there is no sync signal coming into the AES Ref Loop In, it will set up as a Master. See section Multiple Channel Sync’ing, page 81 for an explanation, or the multi-channel applications from page 29 for wiring.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Input Sample Rate For PCM input modes, the input sample rate can be sensed and set automatically, using the Auto option, or forced. The latter is useful where use of 1 or 2 wire mode for higher sample rates might be ambiguous – otherwise Auto is best. It occurs at the bottom of the Input Sample Rate list: Select the required entry from the list and press Set.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 INPUT SAMPLE RATE (kS/s) OUTPUT SAMPLE RATE (kS/s) 11.025 12 16 22.05 24 32 44.1 48 88.2 96 176.4 192 DSD 11.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 For a 2 Pass conversion, convert the input to an intermediate sample rate and either feed it direct into another dCS 974 or record the result, then convert from the intermediate sample rate to the required sample rate. You can always choose one of 44.1 kS/s or 48 kS/s as the intermediate sample rate, so you can record the intermediate pass on most recording devices.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 In Out DSD PCM 192 176.4 176.4 96 96 88.2 48 44.1 DSD DSD 96 88.2 44.1 48 44.1 44.1 44.1 96 Number of Filters Available 8 8 4 4 4 4 4 4 4 4 Table 3 – Conversions with Multiple Filter Options We encourage you to experiment with the filters, to find the one that sounds best for your particular application. Do not assume that one filter is best for all 7 applications! The menu is dynamic - that is, it updates to show valid selections.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Noise Shaping Noise Shaping is a technique in which the noise energy added by truncating a longer word is pushed into the less audible parts of the spectrum - giving a useful improvement in perceived noise level. There is a trade-off between noise floor improvements in the mid-band, where the ear is most sensitive, and increased noise at the top of the audio band, which the ear does not hear but your system might.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 AES Message Edit This menu sets the message bits on the AES outputs. Professional On/Off Select then press Set to toggle between On and Off. Select then press Set to toggle between On and Off. Select the audio data format then press Set.
dCS 974 User Manual dCS Ltd IMPORTANT! Manual for Software Version 1.0x May 2001 Use positive gain with care as the unit does not monitor overloads. If in doubt, use Maximise instead. With Balance set central (i.e. L 0dB, R 0dB), no gain is applied to either channel. Panning to the right attenuates the left but does not amplify the right channel and vice versa. This arrangement helps avoid overloads. To set the balance, select Balance then press Set.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Detect Silence Detect Silence is a PCM only option that gives digital silence out if the unit detects digital silence in. This is useful where dither, and/or noise shaped truncation are being used – without it, even if the signal in goes to digital silence, the output will continue to output low level noise. It allows some automation further along the CD preparation chain. The options are: On Off IMPORTANT! Select then press Set.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 To display a parameter that is not marked, first check that no more than four parameters in the list are marked. If so, select the extra parameter and press Set - an x sign will appear in the box next to it. If five parameters are already marked, select an unwanted one and press Set; the x sign will disappear. Then select the wanted parameter and press Set.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Error Monitor Submenu The dCS 974 keeps count of CRC, Parity and Invalid errors and displays them on the Error Monitoring screen. To view this, go to the top level menu, select Error Monitor and press Status: This shows the error count on Left and Right channels separately since the last reset.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Test Submenu Generator Overview The dCS 974 includes a high quality digital signal test generator, with both sine or square wave outputs, and displays its settings on the Test Mode screen. When invoked, the generator adjusts its output format to that currently operating, and substitutes the generated output for any input signal. The generator operates at the output sample rate.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 To set up the generator, press → twice to move to the menu screen then display the Test menu: The Generator options are Off, Sine and Square. Press Set slowly to scroll through these. There is a short delay while the generator code is loaded. IMPORTANT! The initial Generator Amplitude is -18dB0.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 If you select a frequency that is more than automatically be set to outputFs 2 outputFs 2 , the frequency generator will . Select Generator: Off and press Set - it will toggle to Generator: Sine. Wait several seconds for the code to load up, then press again and it will change to Generator: Square. Press again and it will return to Generator: Off.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Info Submenu To display information about the unit, return to the top level menu, select Info and press Set. The Info screen will be displayed: The first three lines give important details about the hardware and software installed in your dCS 974. This is helpful if you experience difficulties with your unit. Line four is dCS E-mail address for use if you need any further assistance.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Level Meters Submenu Level Meter Overview The Level Meters monitor the Left and Right output signal levels. They work on all PCM signals, and can be used to monitor DSDby setting a DSD to PCM conversion. The dCS 974 can be used purely as a programmable meter. Because the meters work on the output data, the filters can be used to change the bandwidth of the meters.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 None 320ms thru 1600ms Infinite Reset Disables the Peak Hold feature. Sets the Peak Hold time. Sets an infinite Peak Hold time. Resets the Peak Hold segments to the current peak. Select the required option and press Set. Infinite allows the highest peaks in a track or long passage to be displayed – you might want this to do a manual maximise: do this: do this: do this: do this: do this: Select Infinite and press Set.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Display Submenu The final option on the top level menu is Display. Select this and press → : Bright adjusts the brightness of the display backlight and Contrast adjusts the LCD display contrast. These should be set for optimum readability. The length of the solid bars indicate the setting of each parameter - there are 27 levels for each. To adjust the brightness, select Bright and press Set. The cursor will change to the symbol.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Setups and Locking the Front Panel Storing a Setup The dCS 974 features 12 non-volatile user programmable setup stores, labelled Store 0 to Store 11. These are accessed by the rotary control and the block of four MEMORY buttons on the lower left hand corner of the unit. First set up the unit as required then press the Store button.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 If Store 4 has been named Demo, the display will now look similar to this: Press the Enter button and a message window will appear in the display to confirm that the unit is storing the setup. If you attempt to store a setup in a previously unused location without specifying a name, a message window appears for two seconds, stating “First choose a name!”.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Fixed Setups In addition to the 12 user setups, there are 12 fixed setups which cannot be changed. These are contained in the software and may be added to in future software updates. Store A Store B Store C Store D Store E Store F Store G Store H Store I Store J Store K Store L AES1 Au>24 44 Contains default settings: Auto input on AES1, sync to Audio Input, 24 bits 44.1kS/s output in Normal mode.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Either select one of these or press the Recall button again to toggle between the user-defined and fixed setups: Scroll up or down to the required store and press the Enter button. A message window will appear in the display to confirm that the unit is reading the setup. When complete, the display shows the Status screen for the current menu.
dCS 974 User Manual dCS Ltd Manual part no: DOC1241121A1 Contact dCS on + 44 1799 531 999 (inside the UK replace + 44 with 0) Manual for Software Version 1.0x May 2001 Page 65 Document No: OS-MA-A0124-112.1A1 email to: more@dcsltd.co.uk web site: www.dcsltd.co.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 THE HARDWARE – CONTROLS AND CONNECTORS Rear Panel PUSH AES / EBU REFERENCE LOOP PUSH PUSH PUSH SPDIF IN CH1 IN CH2 IN REMOTE dCS 974 more@dcsltd.co.uk OUT IN WCLK IN LOOP OUT CH1 OUT CH2 OUT LOOP IN WCLK OUT AES 1 AES 2 AES 3 AES 4 OUT AES CLK OUT SYNC INPUT BNC DSD / SDIF RCA IN LOOP OUT Disconnect mains before removing cover. See User Manual for installation instructions before connecting supply.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Signal Outputs AES/EBU Digital Outputs 3 pin XLR Male (4 off – AES 1, AES 2, AES 3, AES 4) Used for AES3 format signals. AES 1 and AES 2 (or AES 3 and AES 4) are used together in Dual AES mode. All four outputs are used together for Quad AES or DSD Quad modes. In single AES modes, AES 2, AES 3 and AES 4 outputs follow the AES 1 output.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Front Panel BIT 24 192kS/s OPERATION Status Set Dither Power Noise shaping L/R flip DSD MEMORY Direct Stream Digital Recall Edit Store Phase Enter Gain Balance Unlocked dCS 974 D to D Converter dC S Data Conversion Systems Figure 18 – Front Panel Because of the many options on the dCS 974, we have used a menu based system to control it. The hardware buttons and knobs below navigate you through it.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 LED indicators A group of LED indicators to the right of the LCD display gives a level of status indication: Dither Noise shaping L/R flip Two Phase LEDs Gain Balance Unlocked is lit if any Dither is selected. is lit if any Noise Shaping is selected. indicates that the channels are flipped. indicate if either or both channels are phase inverted. is lit if the setting is other than unity gain (i.e. 0dB).
dCS 974 User Manual dCS Ltd Manual for Software Version 1.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 DSD Filter Options DSD is a single bit very high sample rate (2.822 MS/s) format, where the single bit words are heavily noise shaped to push noise energy above the audio band. The frequency response is very high (well above 100 kHz) although at these high frequencies, noise is also present.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 13 SACD specifies ultrasonic noise in two bands. These are specs informative specs E2 and E3, and filter performance for a number of specs including these are given below. The measurements given have been made using a Fourier Transform based method.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 PCM Input and/or Output Performance Filtering The normal filtering considerations of passband ripple, cutoff frequency and rate, out of band (stop band) suppression, and transient/phase response apply to sample rate converters. The dCS 974 uses linear phase FIR filters to avoid the limit cycle problems that come with many IIR filters.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Figure 20 – Transient Performance of 96 kS/s Filter Options Spurs Sample rate conversion is a linear process, so spurs are not caused by 16 mechanisms that produce harmonic distortion. Spurs are caused by high order 17 images of the baseband input signal aliasing back into the output . The filtering in the converter has to suppress these.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Noise Noise arises from processing rounding errors, and from stop band performance. It is typically around –130dB0, but depends on the conversion being used. Group Delay The conversion process takes time, and the time is dependent on the conversion being carried out, and the filters used. Typical values in microseconds are given for four conversions in the table below. Conversion Filter 1 44.1k ⇒ 96k 88.2k ⇒ 44.1k 96k ⇒ 44.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Clocking The sample clock quality significantly determines the output performance of a DDC, in as far as items connected may have to reconstitute an analogue signal, and may ultimately derive their clock from the DDC clock. The highest quality clocks that are available are crystals, so we use these.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Sample Alignment The dCS 974 aligns samples such that SDIF WCLK OUT aligns with AES3 samples out, the rising edge of wordclock aligning with the start of the first illegal code in the X,Z subframe preamble and the falling edge aligning with the start of the Y subframe preamble. Figure 21 – Wordclock and AES3 outputs, 96 kS/s Figure 22 – Wordclock and AES3 outputs, 44.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 When SDIF WCLK IN is used as a sync source, in and out are related as 18 For below. The lower waveform is the output, the upper one is the input. 44.1 kS/s, out leads in by about 500 ns, and for 96 kS/s it is about 230 ns. Figure 23 – Wordclock in to Wordclock out, 96 kS/s Figure 24 – Wordclock in to Wordclock out, 44.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 AES3 in and out are related as below, where they are at the same sample rate, and the AES3 input is used as a sync source. The alignment is better than 40ns. Input is at the top of the displays, output is at the bottom. Signals are at the sockets on the dCS 974. Figure 25 – AES3 in to AES3 out, 96 kS/s Figure 26 – AES3 in to AES3 out, 44.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 DSD data out is aligned to Wordclock transitions, as below – the wordclock edges align with the data transitions, rather than in the middle of the data eye. If you need them the other way round, use an additional 10m of cable in the WCLK OUT path. Figure 27 – DSD data and Wordclock out Manual part no: DOC1241121A1 Contact dCS on + 44 1799 531 999 (inside the UK replace + 44 with 0) Page 80 Document No: OS-MA-A0124-112.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Multiple Channel Sync’ing Multiple channel sync’ing requires more things to be in sync than two channel work - the PLL must not be dual modulus, the DSP algorithm must load with a constant group delay, and the frame and block syncs must agree. The dCS 974 meets all these constraints with the addition of a syncing signal transmitted from a master unit to subsequent slave units.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Figure 28 – 44.1 kS/s to 96 kS/s PCM, showing AES3 alignment Figure 29 – 96 kS/s to 44.1 kS/s PCM, showing AES3 alignment Manual part no: DOC1241121A1 Contact dCS on + 44 1799 531 999 (inside the UK replace + 44 with 0) Page 82 Document No: OS-MA-A0124-112.1A1 email to: more@dcsltd.co.uk web site: www.dcsltd.co.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Figure 30 – 44.1 kS/s to DSD, showing DSD bit alignment Multiple Channel Multiple Sample Rate Synchronising DVDs can make use of mixed sample rates in their multi-channel mode – for example, 96 kS/s in the front channels and 48 kS/s in the rear channels.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Noise Shaping 22 23 The dCS 974 uses noise shaping that is optimised to the F weighting curve . It does not affect signal frequency or transient response, but shapes the frequency response of errors (Q noise, or truncation errors) so that they fall as much as possible in the less sensitive part of the spectrum. The architecture used also shapes dither, where this is added. For all the major sample rates (32 kS/s, 44.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Dither The dCS 974 uses relatively unusual dither generators to achieve the very good statistics necessary for audio purposes. Many dither generators use PRBS generators (Pseudo Random Binary Shift register generators). These are well known, well documented, and very predictable – but unfortunately their statistics are not that great.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Digital Interface Specifications AES/EBU (AES3) Type Impedance Sensitivity (unloaded) Maximum Wordlength Connector Connections Pin 1 Pin 2 Pin 3 Input Output Balanced, differential 110 110 1 ~ 10 7 24 24 XLR3 female XLR3 male Ground or shield +Signal -Signal Ω V pk-pk bits Table 11 – AES/EBU Interface Electrical Characteristics.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 SPDIF (optical) Type Maximum Wordlength Wavelength Connector Input Output Optical 24 24 660nm Toslink EIAJ CP-340 bits Table 14 – SPDIF Optical Interface Characteristics. IMPORTANT! The Toslink interface is not specified for operation at 88.2 or 96 kS/s due to limitations in the Toslink devices.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Message Handling The dCS 974 strips the message information from the incoming data. The message in the outgoing data is set using the AES Message Edit and SPDIF Message Edit menus, located under the Sample Rate Conversion menu. AES/EBU Message Handling The AES3-1992 standard was written at a time when only 3 sample rates were in common use in the audio industry. dCS started manufacture of ADCs featuring 96 and 88.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 SPDIF Message Handling The SPDIF interface (sometimes known as the Consumer AES/EBU interface) 26 transmits a data structure that conforms to the IEC 958 standard. Like the AES/EBU, this contains 28 bits of Manchester encoded data, and a 4 bit nearManchester encoded preamble in a subframe, and subframes are further assembled in a block and frame structure.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 SDIF-2 Message Handling The SDIF-2 interface is a 4 wire NRZ interface - so the DC level on each signal line may not be constant. It contains 20 bits of audio data and has a block structure of 256 stereo samples, rather than the 192 of AES/EBU. There are 8 bits of message per channel per sample - with a further 3 bits being used for an "illegal code" based sync code.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Power Consumption The dCS 974 has a linear power supply, and so power consumption changes as the supply voltage changes. The internal regulation is comparatively efficient for a linear supply, so these changes are kept to a minimum. Consumption is independent of supply voltage setting.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Size, Weight and Operating Conditions Size and Weight The dCS 974 dimensions correspond to a standard 2U 19" rack mount case. Four heavy duty feet, fitted to the base, extend the overall height to slightly greater than 2U. Dimensions Width Height, without feet Height, with feet Depth Weight note (i) note (ii) note (iii) 430 mm 88 mm 95 mm 390 mm 8.
dCS 974 User Manual dCS Ltd Manual part no: DOC1241121A1 Contact dCS on + 44 1799 531 999 (inside the UK replace + 44 with 0) Manual for Software Version 1.0x May 2001 Page 93 Document No: OS-MA-A0124-112.1A1 email to: more@dcsltd.co.uk web site: www.dcsltd.co.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 dCS 974 PERFORMANCE CURVES The graphs on the following pages show key performances of the dCS 974. • • • • • • • • • • • • • • • • • 27 Dither PDFs, showing how the dither types are effectively ideal, including noise shaped triangular dither FFTs of the dither signals used (excludes truncation, or Q, noise) Raw data for small signal truncated (± 4 lsbs) sinewave, showing source waveform, no dither, and all dither types.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Dither Only Spectra, no Signal dCS 972 SW v1.54 -110 Amplitude (dB) -120 -130 Top Hat dither, actual theoretical Triangular dither, actual theoretical Noise Shaped Triangular dither, actual theoretical -140 44.1 kS/s sampling, 16 bit dither, 1024 point FFTs, H6 window -150 0 2 4 6 8 10 12 14 16 18 20 22 Frequency (kHz) Figure 32 – Dither Spectra (FFTs) Raw Data for Source and Truncated Small Signal dCS 972 SW v1.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Spectra of -90dB 24 bit sinewave truncated to 16 bits with dither options dCS 972 SW v1.54 -60 44.1 kS/s sampling, -90 dB 1.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Spot Q Noise for DSD Filters in 400 Hz bandwidth 0 F1 F2 F3 F4 F5 F6 F7 -120dB in 20 kHz -20 Q Noise rel Full Scale DSD (dB) -40 -60 -80 -100 -120 -140 -160 -180 -200 1 10 100 1000 Frequency (kHz) Figure 36 – DSD output, spot Q Noise for the various Filter options Integrated Q Noise for DSD Filters normalised for Full Scale DSD at 0dB 20.00 F1 0.00 F2 F3 F4 -20.00 Integrated Q Noise Power (dB) F5 F6 -40.00 F7 -60.00 -80.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Spot Q Noise for DSD Filters, F Weighted in 400 Hz bandwidth 20 -80 F1 -100 0 F2 F3 -120 -20 F4 -40 F5 F6 -160 -60 F7 -180 -80 F weighting curve (right hand scale) -200 -100 -220 -120 -240 -140 -260 -160 F weighting (dB) Q Noise rel Full Scale DSD (dB) -140 -180 -280 0.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 48 kS/s to 44.1 kS/s Filters dCS 972 SW v1.54 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 0.100 10 0.075 0 Normal axis axis - to right 0.050 -10 0.025 -20 -30 Zoomed axis - to left -0.025 -40 -0.050 -50 Filt 1 -0.075 -60 Filt 2 -0.100 -70 Filt 3 -0.125 -80 Filt 4 -0.150 -90 -0.175 -100 -0.200 -110 -0.225 -120 -0.250 -130 -0.275 -140 -0.300 0 4.41 8.82 13.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 32 kS/s Noise Shape Plots dCS 972 SW v1.54 24 Noise Amplitude relative to No Shaping (dB) 18 12 2nd or 6th Order Recommended 6 0 Order 1 Order 2 -6 Order 3 Order 4 Order 5 -12 Order 6 Order 7 Order 8 -18 Order 9 Order 10 -24 0 4 8 12 16 Frequency (kHz) Figure 42 – 32 kS/s noise shaper curves 44.1 kS/s Noise Shape Plots dCS 972 SW v1.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 48 kS/s Noise Shape Plots dCS 972 SW v1.54 36 30 Noise Amplitude relative to No Shaping (dB) 24 18 2nd or 8th Order Recommended 12 6 0 Order 1 -6 Order 2 Order 3 -12 Order 4 Order 5 -18 Order 6 Order 7 -24 Order 8 Order 9 -30 Order 10 -36 0 4 8 12 16 20 24 Frequency (kHz) Figure 44 – 48 kS/s noise shaper curves 88.2 kS/s Noise Shape Plots dCS 972 SW v1.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 96kS/s Noise Shape Plot dCS 972 SW v1.54 36 30 Noise Amplitude relative to No Shaping (dB) 24 18 12 6 0 -6 -12 Order 1 -18 Order 2 -24 Order 3 3rd or 7th Order Recommended Order 4 -30 Order 5 -36 Order 6 -42 Order 7 Order 8 -48 Order 9 -54 Order 10 -60 0 4 8 12 16 20 24 28 32 36 40 44 48 Frequency (kHz) Figure 46 – 96 kS/s noise shaper curves Weighted Noise Improvement vs Shaper Order dCS 972 SW v1.
dCS 974 User Manual dCS Ltd Manual part no: DOC1241121A1 Contact dCS on + 44 1799 531 999 (inside the UK replace + 44 with 0) Manual for Software Version 1.0x May 2001 Page 103 Document No: OS-MA-A0124-112.1A1 email to: more@dcsltd.co.uk web site: www.dcsltd.co.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 GENERAL TECHNICAL INFORMATION Word Length Reduction Word length reduction (truncation) causes an error signal to be added to the wanted signal. The error signal is usually referred to as “Q noise” or Quantisation noise – the approximation is made that the errors are noise-like. This is true for large signals, but for smaller ones it is not so.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 The 0 dB reference level is taken as the minimum noise we could possibly get away with – the amount that simple 16 bit truncation (16 bit Q noise) would give, if it were well behaved, which it is not. Straight forward dither always adds noise – it can only produce signals with a noise floor higher than Q noise on its own. However, the noise power added is a few dBs for simple types.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Noise shaping on its own is not perfect. It relies on a small amount of noise in the input signal to generate the frequency shaped correction signal, and if there is very low noise in the input signal, this mechanism can break down. In reality, 31 such a situation can only occur with test signals, digitally generated signals , or silences introduced in editing.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Noise Shaper, Noise Shaper with Dither, and Dither Only Comparison dCS 972 SW v1.54 -60 16 bit truncation, Noise Shaped Triangular dither 16 bit truncation, Top Hat dither -80 16 bit truncation, 10th order noise shaping, Noise Shaped Triangular dither Amplitude, Real Data (dB) 16 bit truncation, 10th order noise shaping, no dither -100 -120 -140 44.1 kS/s sampling, 1024 point FFTs, H6 window, -90 dB 1.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 When is Dither Needed? Dither (on its own or with noise shaping) is not always needed. The condition for not being needed depends on the level of noise in the incoming signal, the amount of noise shaping being used, and the output word length. The user may want to avoid having to think about this at all – in which case, use Noise Shaped Triangular dither – or may wish to minimise noise and added noise.
dCS 974 User Manual dCS Ltd Manual part no: DOC1241121A1 Contact dCS on + 44 1799 531 999 (inside the UK replace + 44 with 0) Manual for Software Version 1.0x May 2001 Page 109 Document No: OS-MA-A0124-112.1A1 email to: more@dcsltd.co.uk web site: www.dcsltd.co.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 USING YOUR dCS 974 FOR THE FIRST TIME What’s in the Box? The contents of the box are at least: dCS 974 User Manual Quick Start Guide Power cable 2 Spare Fuses Remote cable Remote software Supply Voltage Setting The dCS 974 is shipped with its supply voltage preset for operation in the destination country. The voltage is not intended to be changed by the user.
dCS 974 User Manual dCS Ltd do this: Manual for Software Version 1.0x May 2001 Press the Recall button. When the display changes to the Recall screen, press the Recall button again. The display will change to: do this: Select Store A (the default setting) with the rotary control and press the Enter button. A message window will appear in the display to confirm that the unit is reading the setup. Then, when complete, the message will go away, the unit will lock and the Unlocked LED will go out.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Installing the Unit in a Rack The unit is supplied with 19" rack mount ears fitted. If it is to be installed in a 19" rack, the ears supplied may be used to locate it in the rack - but: IMPORTANT! The ears should not be used as the only mechanical support. The unit should rest on a shelf, or be supported in some other way. The ears will just locate it in the rack, and stop it sliding forwards.
dCS 974 User Manual dCS Ltd Manual part no: DOC1241121A1 Contact dCS on + 44 1799 531 999 (inside the UK replace + 44 with 0) Manual for Software Version 1.0x May 2001 Page 113 Document No: OS-MA-A0124-112.1A1 email to: more@dcsltd.co.uk web site: www.dcsltd.co.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 OPTIONS The following options may be fitted to new units or retrofitted at a later date. Option code VID V5 V4 V2 V1 Option Locking to video sample rates Mains voltage set to 230/240V Mains voltage set to 215/220V Mains voltage set to 115/120V Mains voltage set to 100V Table 17 - Options available Locking to Video Sample Rates We can fit additional video frequency VCXO’s (enabling frequencies such as 44.056kS/s and 47.952kS/s).
dCS 974 User Manual dCS Ltd Manual part no: DOC1241121A1 Contact dCS on + 44 1799 531 999 (inside the UK replace + 44 with 0) Manual for Software Version 1.0x May 2001 Page 115 Document No: OS-MA-A0124-112.1A1 email to: more@dcsltd.co.uk web site: www.dcsltd.co.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 MAINTENANCE AND SUPPORT Hardware Service & Maintenance dCS audio products are designed not to need regular maintenance, and contain no user serviceable parts: • • • • there are no moving parts, there are no short life or wear-out parts used, the units have no holes through which liquids or contamination can normally enter, no dust deposits build up to degrade performance.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Software Installing New Software There are two major components of software in your unit. These are the operating software, and the display software. The operating software can be downloaded via the RS-232 link from a PC COM port, using the Windows Remote software running on the PC. To use this, follow the installation instructions on the floppy discs the remote software is supplied on.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Warranty Initial Warranty dCS Ltd. warrant this product against defects in materials and workmanship for a period of 90 days from receipt by the end user. Warranty repairs must only be carried out by dCS or an authorised dCS Distributor. Extended Warranty The period of the Warranty cover may be extended to 1 year from receipt by the end user at no extra cost, by registering your purchase with dCS.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Update or Calibration You may wish to have your unit updated occasionally. dCS offer this service we will install any modifications or updates that have occurred since your unit was first shipped, and give the unit a full retest to current standards. The price will depend on the hardware changes necessary – so contact your dealer or us. In order to ensure speedy turn around please contact us prior to returning the unit.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 TROUBLESHOOTING FAQs The unit fails to lock to a source signal. • • • • Check that Audio Input Select is set to the correct input. Check that Input Sample Rate is either set to Auto or set to suit the source device. Check that Sync Source is set correctly - try setting it to Audio Input. Check for damaged cables. The unit locks but no signal is received.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Output audio bandwidth is low. • During sample rate conversion, the signal is digitally filtered - this is essential for good performance. The output audio bandwidth will usually be slightly less than half the lowest sample frequency involved in the conversion. A stereo output signal is expected but signal is present on one channel only. • • • Check that Balance is not set to one side.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 “Invalid Fs Out for Fs In” message. • • You have selected a combination that cannot be handled in one pass - see the table in the section Output Sample Rate on page 43 for valid single pass combinations. Choose an intermediate sample rate and convert in two passes. For example, if you need to convert from 32 kS/s to 11.025 kS/s, first convert to 44.1 kS/s and record then convert the recording from 44.1 kS/s to 11.025 kS/s.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 If You Need More Help Contact dCS. Our office hours are 8:00 a.m. to 5:00 p.m. Monday to Friday, UK time (UTC or UTC + 1hr). Contact us by phone or fax on: Inside the UK Telephone 01799 531 999 Fax 01799 531 681 Table 18 – dCS Phone Numbers Outside the UK +44 1799 531 999 +44 1799 531 681 You can write to us at: dCS Ltd Mull House Great Chesterford Court Great Chesterford Saffron Walden CB10 1PF UK Our E-Mail address: more@dcsltd.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 INDEXES AND SOFTWARE VERSION NUMBERS This manual is for software version 1.0x. v1.0x versions differ only in a few minor bug fixes. Definitions of Units dB0 Level in decibels, referred to a full scale sine wave in a sampled system. So, 0 dB0 is full scale. dB0DSD Level in decibels, referred to the defined full scale sine wave in a DSD system. So, 0 dB0DSD is the zero dB audio reference level.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Figures Figure 1 – Audio Input Selection ....................................................................... 11 Figure 2 – Sync Source Selection ..................................................................... 13 Figure 3 – Pure Format Conversion .................................................................. 15 Figure 4 – Sample Rate Conversion .................................................................
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Keywords and Phrases customising the display................................. 50 # ← button ........................................................68 2 24 bit operation..............................................19 24/96 to CD....................................................22 2-pass conversions............................43, 44, 45 A aborting a store or recall................................64 AES Clock output ..................
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 I Dual AES to single wire .................................23 E Edit button................................................61, 68 editing a store name ......................................61 Enter button .............................................62, 68 error hold .......................................................52 Error Monitor menu..................................39, 52 error reported by destination device............
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 Maximise, using .............................................49 Memory buttons, using ..................................61 menu tree.......................................................35 menu, navigating ...........................................36 menu, using ...................................................36 message handling .........................................70 mode, FC .................................................
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 selecting an input...........................................11 selecting DSD Quad input .............................12 selecting DSD SDIF input..............................12 selecting Dual AES input ...............................12 selecting Quad AES input..............................12 selecting SDIF-2 input ...................................11 Self Test, display ...........................................
dCS 974 User Manual dCS Ltd Manual part no: DOC1241121A1 Contact dCS on + 44 1799 531 999 (inside the UK replace + 44 with 0) Manual for Software Version 1.0x May 2001 Page 130 Document No: OS-MA-A0124-112.1A1 email to: more@dcsltd.co.uk web site: www.dcsltd.co.
dCS 974 User Manual dCS Ltd Manual for Software Version 1.0x May 2001 2nd Owner Owner Registration Transfer To transfer the balance of the Extended Warranty to a new owner, please complete the form below in block capitals and forward it, with the Extended Warranty Certificate, to dCS at the address below within 30 days of the sale. dCS Ltd Mull House Great Chesterford Court Great Chesterford Saffron Walden CB10 1PF U.K.
