User's Guide Hammerfall® DSP System HDSP 9652 ™ TotalMix 24 Bit / 96 kHz 9 ® SyncAlign ZLM ® ® SyncCheck PCI Busmaster Digital I/O System 2 + 24 Channels SPDIF / ADAT Interface 24 Bit / 96 kHz Digital Audio ADAT Sync In 2 x MIDI I/O
General 1 2 3 4 5 6 Introduction ...............................................................6 Package Contents .....................................................6 System Requirements ..............................................6 Brief Description and Characteristics.....................6 Hardware Installation................................................7 Hardware – Connectors 6.1 External Connectors ..............................................7 6.2 Internal Connectors.........................
Driver Installation and Operation - Mac OS X 18 Driver and Flash Update 19.1 Driver Installation ................................................. 30 19.2 Driver Update....................................................... 30 19.3 Flash Update........................................................ 30 19 Configuring the HDSP 9652 20.1 Settings Dialog..................................................... 31 20.2 Clock Modes – Synchronization .......................... 33 20 Mac OS X FAQ 21.
25 TotalMix: The Matrix 27.1 Overview ..............................................................57 27.2 Elements of the Matrix View ................................57 27.3 Usage...................................................................57 27.4 Advantages of the Matrix .....................................58 26 TotalMix Super-Features 28.1 ASIO Direct Monitoring (Windows only) ..............58 28.2 Selection and Group based Operation ................59 28.3 Copy Routings to other Channels ......
User's Guide HDSP 9652 General User's Guide HDSP System HDSP 9652 © RME 5
1. Introduction Thank you for choosing the RME Hammerfall DSP system. This unique audio system is capable of transferring analog and digital audio data directly to a computer from practically any device. The latest Plug and Play technology guarantees a simple installation, even for the inexperienced user. The numerous unique features and well thought-out configuration dialog puts the Hammerfall DSP at the very top of the range of computer-based audio interfaces.
5. Hardware Installation Before installing the PCI card, please make sure the computer is switched off and the power cable is disconnected from the mains supply. Inserting or removing a PCI card while the computer is in operation can cause irreparable damage to both motherboard and card! 1. Disconnect the power cord and all other cables from the computer. 2. Remove the computer's housing. Further information on how to do this can be obtained from your computer’s instruction manual. 3.
Word Clock I/O (BNC). When shipped, the word clock input is not terminated. Termination with 75 Ohm is available via jumper X105 on the Expansion Board. The included MIDI breakout cable is connected to the 9-pin Mini-DIN connector, providing two MIDI inputs and outputs. Note: If neither Word Clock I/O, MIDI I/O, nor a third ADAT I/O is required, it is not necessary to install the Expansion Board at all. 6.
7. Accessories RME offers several optional accessories. Also parts of the HDSP 9652 are available separately. Part Number 36003 36004 36006 36007 36008 36009 Description Optical cable, TOSLINK, 0.5 m (1.6 ft) Optical cable, TOSLINK, 1 m (3.3 ft) Optical cable, TOSLINK, 2 m (6.6 ft) Optical cable, TOSLINK, 3 m (9.9 ft) Optical cable, TOSLINK, 5 m (16.4 ft) Optical cable, TOSLINK, 10 m (33 ft) Standard lightpipe with TOSLINK connectors, RME approved quality.
Although the contents of this User’s Guide have been thoroughly checked for errors, RME can not guarantee that it is correct throughout. RME does not accept responsibility for any misleading or incorrect information within this guide. Lending or copying any part of the guide or the RME Driver CD, or any commercial exploitation of these media without express written permission from RME Intelligent Audio Solutions is prohibited. RME reserves the right to change specifications at any time without notice.
User's Guide HDSP 9652 Driver Installation and Operation - Windows User's Guide HDSP System HDSP 9652 © RME 11
10. Driver and Firmware 10.1 Driver Installation After the PCI card has been installed correctly (see 5. Hardware Installation), and the computer has been switched on, Windows will recognize the new hardware component and start its ‘Hardware Wizard’. Insert the RME Driver CD into your CD-ROM drive, and follow further instructions which appear on your computer screen. The driver files are located in the directory \WDM on the RME Driver CD.
10.3 De-Installing the Drivers A de-installation of the HDSP driver files is not necessary – and not supported by Windows anyway. Thanks to full Plug & Play support, the driver files will not be loaded after the hardware has been removed. If desired these files can then be deleted manually. Unfortunately Windows Plug & Play methods do not cover the additional autorun entries of TotalMix, the Settings dialog, and the registration of the ASIO driver.
11. Configuring the HDSP 9652 11.1 Settings Dialog Configuration of the HDSP 9652 is done via its own settings dialog.
Options AEB activates the internal connector as ADAT1 input instead of the optical TOSLINK. An expansion board (AEB4-I, AEB8-I, TEB) can be connected here. TMS activates the transmission of Channel Status data and Track Marker information for the SPDIF input. WDM Devices Not before Vista the OS had been capable to handle more than 32 WDM stereo devices. Therefore under W2k/XP it often makes sense to intentionally limit their number. SPDIF In Defines the input for the SPDIF signal.
About This tab includes information about the driver and the card’s firmware version. Lock Registry uses a password to prevent changes of the settings stored in the registry. All settings are still changeable temporarily. As the settings are always loaded from the registry when starting the computer, this method provides an easy way to define a specific initial state of the HDSP system. 11.
To cope with some situations which may arise in studio practice, setting ‘Pref Sync Ref’ is essential. One example: An ADAT recorder is connected to the ADAT1 input (ADAT1 immediately becomes the sync source) and a CD player is connected to the SPDIF input. Try recording a few samples from the CD and you will be disappointed. Few CD players can be synchronized. The samples will inevitably be corrupted, because the signal from the CD player is read with the (wrong) clock from the ADAT i.e. out of sync.
12. Operation and Usage 12.1 Playback The HDSP system can play back audio data only in supported modes (channels, PCM) and formats (sample rate, bit resolution). Otherwise an error message appears (for example at 22 kHz and 8 bit). In the audio application being used, HDSP must be selected as output device. This can often be found in the Options, Preferences or Settings menus under Playback Device, Audio Devices, Audio etc. We strongly recommend switching off all system sounds (via >Control Panel /Sounds<).
12.2 DVD-Playback (AC-3/DTS) AC-3 / DTS When using popular DVD software players like WinDVD and PowerDVD, their audio data stream can be sent to any AC-3/DTS capable receiver via the 9652’s AES and SPDIF output. For this to work an output wave device has to be selected in >Control Panel/ Sounds and Multimedia/ Audio< or >Control Panel/ Sound/Playback<. Also check 'use preferred device only'. The DVD software's audio properties now show the options 'SPDIF Out' or similar.
12.3 Notes on WDM The driver offers a WDM streaming device per stereo pair, like HDSP 9652 ADAT (1+2). WDM streaming is Microsoft's current driver and audio system, directly embedded into the operating system. WDM streaming is hardly usable for professional music purposes, as all data is processed by the so called Kernel Mixer, causing a latency of at least 30 ms.
WDM Stereo device HDSP 9652 ADAT (1+2) HDSP 9652 ADAT (3+4) HDSP 9652 ADAT (5+6) HDSP 9652 ADAT (7+8) HDSP 9652 ADAT (9+10) HDSP 9652 ADAT (11+12) HDSP 9652 ADAT (13+14) HDSP 9652 ADAT (15+16) HDSP 9652 ADAT (17+18) HDSP 9652 ADAT (19+20) HDSP 9652 ADAT (21+22) HDSP 9652 ADAT (23+24) HDSP 9652 SPDIF Double Speed HDSP 9652 ADAT (1+2) HDSP 9652 ADAT (3+4) HDSP 9652 ADAT (5+6) HDSP 9652 ADAT (7+8) HDSP 9652 ADAT (9+10) HDSP 9652 ADAT (11+12) HDSP 9652 ADAT (13+14) HDSP 9652 ADAT (15+16) HDSP 9652 ADAT (17+18)
Multi-Client and Multi-Channel using WDM The WDM streaming devices of our driver can operate as usual stereo devices, or as 8-channel devices. The option Interleaved in the Settings dialog determines the current mode. Interleaved not active: The WDM devices operate as usual stereo devices. The multi-client operation works as described above with WDM, ASIO and GSIF. Interleaved active: The WDM devices can also be used as 8-channel devices.
It often makes sense to monitor the input signal or send it directly to the output. This can be done at zero latency using TotalMix (see chapter 24). An automated control of real-time monitoring can be achieved by Steinberg’s ASIO protocol with our ASIO drivers and all ASIO 2 compatible programs. When 'ASIO Direct Monitoring' has been switched on, the input signal is routed in real-time to the output whenever a recording is started (punch-in). 13. Operation under ASIO 13.
13.3 Known Problems If a computer does not provide sufficient CPU-power and/or sufficient PCI-bus transfer rates, then drop outs, crackling and noise will appear. We recommend to deactivate all PlugIns to verify that these are not the reason for such effects. Additional hard disk controllers, both on-board and PCI based, often violate the PCI specs. To achieve the highest throughput they hog the PCI bus, even in their default setting. Thus when working with low latencies heavy drop outs (clicks) are heard.
14. Operation under GSIF (Gigasampler Interface) The GSIF interface of the Hammerfall DSP allows direct operation with Gigastudio, with up to 26 channels, 96 kHz and 24 bit. The new GSIF 2.0 is also supported with both audio and MIDI. The GSIF latency of the HDSP 9652 can be set between 32 and 256 samples. Above 256, only the ASIO latency will rise. Such a setting can prevent performance problems on slower machines when using ASIO and GSIF at the same time.
16. DIGICheck The DIGICheck software is a unique utility developed for testing, measuring and analysing digital audio streams. Although this software is fairly self-explanatory, it still includes a comprehensive online help. DIGICheck 5.2 operates as multi-client ASIO host, therefore can be used in parallel to any software with both inputs and outputs (!). The following is a short summary of the currently available functions: • Level Meter. High precision 24-bit resolution, 2/8/36 channels.
17. Hotline – Troubleshooting 17.1 General The newest information can always be found on our website www.rme-audio.com, section FAQ, Latest Additions. The input signal cannot be monitored in real-time • ASIO Direct Monitoring has not been enabled, and/or monitoring has been disabled globally (for example in TotalMix). The 8 ADAT channels don’t seem to work • The optical output ADAT1 has been switched to 'SPDIF'.
The ADAT timecode is not in sync • The tape is formatted to 48 kHz, but played back at 44.1 kHz (Pitch). This 'Blackface' problem cannot be solved in a satisfactory way. 17.2 Installation HDSP 9652 is found in the Device Manager (>Settings/ Control Panel/ System<), category 'Sound-, Video- and Gamecontroller'. A double click on 'HDSP 9652' starts the properties dialog. Choosing 'Resources' shows interrupt and memory range. The newest information on hardware problems can always be found on our website www.
User's Guide HDSP 9652 Driver Installation and Operation – Mac OS X User's Guide HDSP System HDSP 9652 © RME 29
18. Driver and Flash Update 18.1 Driver Installation First fit the card (see 5. Hardware Installation), then switch on the computer and install the drivers from the RME Driver CD. The driver file is located in the folder Hammerfall DSP. Installation works automatically by a double-click on the file hdsp.mpkg. RME recommends to download the latest driver version from the RME website! If done, the procedure is as follows: Double-click onto hdsp_16c.gz to expand the archive file to hdsp_16c.
19. Configuring the HDSP 9652 19.1 Settings Dialog Configuring the HDSP 9652 is done via its own settings dialog. The panel 'Settings' can be opened by clicking on the hammer icon in the dock. The mixer of the Hammerfall DSP System, TotalMix, can be opened by clicking on the mixer icon in the dock. The Hammerfall DSP’s hardware offers a number of helpful, well thought-of practical functions and options which affect how the card operates - it can be configured to suit many different requirements.
Clock Mode The unit can be configured to use its internal clock source (Master), or the clock source predefined via Pref. Sync Ref (AutoSync). Pref Sync Ref Used to pre-select the desired clock source. If the selected source isn't available, the unit will change to the next available one. The current clock source and sample rate is displayed in the AutoSync Ref display. The automatic clock selection checks and changes between the clock sources Word Clock, ADAT optical, ADAT Sync and SPDIF.
19.2 Clock Modes - Synchronisation In the digital world, all devices are either the ‘Master’ (clock source) or a ‘Slave’ synchronized to the master. Whenever several devices are linked within a system, there must always be a single master clock. The Hammerfall DSP’s intelligent clock control is very user-friendly, being able to switch between clock modes automatically. Selecting AutoSync will activate this mode. In AutoSync mode, the system constantly scans all digital inputs for a valid signal.
If several digital devices are to be used simultaneously in a system, they not only have to operate with the same sample frequency but also be synchronous with each other. This is why digital systems always need a single device defined as ‘master’, which sends the same clock signal to all the other (‘slave’) devices. RME’s exclusive SyncCheck technology (first implemented in the Hammerfall) enables an easy to use check and display of the current clock status.
20. Mac OS X FAQ 20.1 Round about Driver Installation The driver with the file suffix gz provided by RME is a compressed TAR archive. TAR bundles multiple files and folders into one file, but does not save memory space nor download time. Both TAR and gz are supported natively by OS X, a double click on the file is all you need to do. Older browsers do not recognize gz as an archive, loading the file as a document. This results in a cryptic looking text within the browser window.
20.3 Supported Sample Rates RME's Mac OS X driver supports all sampling frequencies provided by the hardware. Besides 96 kHz this also includes 32 kHz and 64 kHz. But not every software will support all the hardware's sample rates. The hardware's capabilities can easily be verified in the Audio MIDI Setup. Select Audio devices under Properties of: and choose the Hammerfall DSP. A click on Format will list the supported sample frequencies.
21.6 Various Information The driver requires 10.2.8 or higher. Older versions of OS X are not and will not be supported. Via >System Preferences/ Audio-MIDI Setup< the hardware can be configured for the system wide usage. Programs that don't support card or channel selection will use the device selected as Standard-Input and Standard-Output. (Soundstudio, Mplayer, Amplitube etc.). In the lower part of the window, the audio hardware's capabilities are shown and can be changed in some cases.
User's Guide HDSP System HDSP 9652 © RME
User's Guide HDSP 9652 Connections and TotalMix User's Guide HDSP System HDSP 9652 © RME 39
22. Digital Connections 22.1 ADAT The ADAT optical input of the HDSP system is fully compatible with all ADAT optical outputs. RME's unsurpassed Bitclock PLL prevents clicks and drop outs even in extreme varipitch operation, and guarantees a fast and low jitter lock to the digital input signal. A usual TOSLINK cable is sufficient for connection. More information on Double Speed (S/MUX) can be found in chapter 32.3. ADAT 1 In Interface for a device sending an ADAT signal to the HDSP 9652.
Note that in record or monitor modes, set emphasis bits will disappear. Recordings originally done with emphasis should always be played back with the emphasis bit set! This can be done by selecting the Emphasis switch in the Settings dialog (field SPDIF Out). This setting is updated immediately, even during playback. The HDSP 9652’s new output header is optimized for largest compatibility with other digital devices: • • • • • • • 32 kHz, 44.1 kHz, 48 kHz, 88.
23. Word Clock 23.1 Technical Description and Usage In the analog domain one can connect any device to another device, a synchronisation is not necessary. Digital audio is different. It uses a clock, the sample frequency. The signal can only be processed and transmitted when all participating devices share the same clock. If not, the signal will suffer from wrong samples, distortion, crackle sounds and drop outs.
The HDSP 9652’s word clock input can be high-impedance or terminated internally, ensuring maximum flexibility. If termination is necessary (e.g. because HDSP 9652 is the last device in the chain), bring jumper X105 on the Expansion Board into position 75 Ohm. In case the HDSP 9652 resides within a chain of devices receiving word clock, plug a T-adapter into its BNC input jack, and the cable supplying the word clock signal to one end of the adapter.
24. TotalMix: Routing and Monitoring 24.1 Overview The HDSP 9652 includes a powerful digital real-time mixer, the Hammerfall DSP mixer, based on RME’s unique, sample-rate independent TotalMix technology. It allows for practically unlimited mixing and routing operations, with all inputs and playback channels simultaneously, to any hardware outputs. Here are some typical applications for TotalMix: • Setting up delay-free submixes (headphone mixes).
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24.2 The User Interface The visual design of the TotalMix mixer is a result of its capability to route hardware inputs and software playback channels to any hardware output. The HDSP 9652 provides 26 input channels, 26 software playback channels, and 26 hardware output channels: 52 channels don't fit on the screen side by side, neither does such an arrangement provide a useful overview. The input channel should be placed above the corresponding output channel.
24.3 Elements of a Channel A single channel consists of various elements: Input channels and playback channels each have a mute and solo button. Below there is the panpot, realized as indicator bar (L/R) in order to save space. In the field below, the present level is displayed in RMS or Peak, being updated about every half a second. Overs (overload) are indicated here by an additional red dot. Next is the fader with a level meter.
You see, it is very easy to set up a specific submix for whatever output: select output channel, set up fader and pans of inputs and playbacks – ready! For advanced users sometimes it makes sense to work without Submix View. Example: you want to see and set up some channels of different submixes simultaneously, without the need to change between them all the time. Switch off the Submix View by a click on the green button.
You will certainly have noticed that the signal at the outputs 7/8 did not change while you were routing channel 4 to other outputs and setting different gain values for those. With all analog and most digital mixing desks, the fader setting would affect the level for every routed bus - not so for TotalMix. TotalMix allows for setting all fader values individually. Therefore the faders and the panpots jump to the appropriate setting as soon as another routing is chosen.
24.7 The Quick Access Panel This section includes additional options, further improving the handling of TotalMix. The Master buttons for Mute and Solo have already been described, they allow for group-based working with these functions. In the View section the single mixer rows can be made visible or invisible. If the inputs are not needed for a pristine playback mix, the whole upper row falls out of the picture after a click on the Input button.
Mouse: The original factory presets can be reloaded by holding down the Ctrl-key and clicking on any preset button. Alternatively the files described above can be renamed, moved to a different directory, or being deleted. Keyboard: Using Ctrl and any number between 1 and 8 (not on the numeric keypad) will load the corresponding factory default preset. The key Alt will load the user presets instead. When loading a preset file, for example 'Main Monitor AN 1_2 plus headphone mix 3_4.
24.9 The Monitor Panel The Monitor panel provides several options usually found on analog mixing desks. It offers quick access to monitoring functions which are needed all the time in typical studio work. Monitor Main Use the drop down menu to select the hardware outputs where your main monitors are connected to. Dim A click on this button will lower the volume of the Monitor Main output by an amount set up in the Preferences dialog (see below).
Monitor Main Dim: Amount of attenuation of the Monitor Main output in dB. Activated by the Dim button in the Monitor panel. Stereo Pan Law The Pan Law can be set to -6 dB, -4.5 dB, -3 dB and 0 dB. The value chosen defines the level attenuation in pan center position. This setting is useful because the ASIO host often supports different pan laws too. Selecting the same value here and in the ASIO host, ASIO Direct Monitoring works perfectly, as both ASIO host and TotalMix use the same pan law.
24.12 Hotkeys In many situations TotalMix can be controlled quickly and comfortably by the keyboard, making the mixer setup considerably easier and faster. The Shift-key for the fine mode for faders and panpots has already been mentioned. The Ctrl-key can do far more than changing the routing pairwise: • Clicking anywhere into the fader area with the Ctrl-key pressed, sets the fader to 0 dB. • Clicking anywhere into the pan area with the Ctrl-key pressed, sets the panorama to meaning Center.
24.13 Menu Options Always on Top: When active (checked) the TotalMix window will always be on top of the Windows desktop. Note: This function may result in problems with windows containing help text, as the TotalMix window will even be on top of those windows, so the help text isn't readable. Deactivate Screensaver: When active (checked) any activated Windows screensaver will be disabled temporarily. Ignore Position: When active, the windows size and position stored in a file or preset will not be used.
24.14 Level Meter The HDSP 9652 calculates all the display values Peak, Over and RMS in hardware, in order to be capable of using them independent of the software in use, and to significantly reduce the CPU load. Tip: This feature, the Hardware Level Meter, is used by DIGICheck (see chapter 16) to display Peak/RMS level meters of all channels, nearly without any CPU load. The level meters integrated in TotalMix - considering their size - cannot be compared with DIGICheck.
25. TotalMix: The Matrix 25.1 Overview The mixer window of TotalMix looks and operates similar to mixing desks, as it is based on a conventional stereo design. The matrix display presents a different method of assigning and routing channels, based on a single channel or monaural design. The matrix view of the HDSP has the looks and works like a conventional patchbay, adding functionality way beyond comparable hardware and software solutions.
25.4 Advantages of the Matrix The Matrix not always replaces the mixer view, but it significantly enhances the routing capabilities and - more important - is a brilliant way to get a fast overview of all active routings. It shows you in a glance what's going on. And since the Matrix operates monaural, it is very easy to set up specific routings with specific gains.
26.2 Selection and Group-based Operation Click on the white name label of channel 1 and 2 in TotalMix. Be sure to have channel 3's fader set to a different position and click on its label too. All three labels have changed to the colour orange, which means they are selected. Now moving any of these faders will make the other faders move too. This is called 'building a group of faders', or ganging faders, maintaining their relative position.
26.5 Recording a Subgroup (Loopback) TotalMix supports a routing of the subgroup outputs (=hardware outputs, bottom row) to the recording software. Unfortunately this feature is not available with the HDSP 9652, as the FPGA of the card has no resources left for a hardware implementation. Therefore this chapter describes the loopback mode when used with an external cable loop. A loopback is used to record the playback signal.
26.6 Using external Effects Devices With TotalMix a usage of external hardware - like effects devices - is easy and flexible. Example 1: The singer (microphone input channel 1) shall have some reverb on his headphones (outputs 25/26). A direct routing In 1 to Out 25/26 for monitoring had been set up already. The external reverb is connected to a free output, for example channel 8. In active mode Submix View click on channel 8 in the bottom row.
27. TotalMix MIDI Remote Control 27.1 Overview TotalMix can be remote controlled via MIDI. It is compatible to the widely spread Mackie Control protocol, so TotalMix can be controlled with all hardware controllers supporting this standard. Examples are the Mackie Control, Tascam US-2400 or Behringer BCF 2000. Additionally, the stereo output faders (lowest row) which are set up as Monitor Main outputs in the Monitor panel can also be controlled by the standard Control Change Volume via MIDI channel 1.
27.3 Setup • Open the Preferences dialog (menu Options or F3). Select the MIDI Input and MIDI Output port where your controller is connected to. • When no feedback is needed (when using only standard MIDI commands instead of Mackie Control protocol) select NONE as MIDI Output. • Check Enable MIDI Control in the Options menu. 27.4 Operation The channels being under MIDI control are indicated by a colour change of the info field below the faders, black turns to yellow.
27.5 Simple MIDI Control The stereo output faders (lowest row) which are set up as Monitor Main outputs in the Monitor panel can also be controlled by the standard Control Change Volume via MIDI channel 1. With this, the main volume of the HDSP 9652 is controllable from nearly any MIDI equipped hardware device. Even if you don't want to control all faders and pans, some buttons are highly desired to be available in 'hardware'.
Examples for sending MIDI strings*: - Set input 1 to 0 dB: B0 66 40 - Set input 17 to maximum attenuation: B1 66 0 - Set playback 1 to maximum: B4 66 7F - Set Output 16 to 0 dB: B8 75 40 *Note: Sending MIDI strings might require the use of programmer's logic for the MIDI channel, starting with 0 for channel 1 and ending with 15 for channel 16. 27.6 Loopback Detection The Mackie Control protocol requires feedback of the received commands, back to the hardware controller.
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User's Guide HDSP 9652 Technical Reference User's Guide HDSP System HDSP 9652 © RME 67
28. Tech Info Not all information to and around our products fit in a manual. Therefore RME offers a lot more and detailed information in the Tech Infos. The very latest Tech Infos can be found on our website, section Support. These are some of the currently available Tech Infos: Synchronization II (DIGI96 series) Digital audio synchronization - technical background and pitfalls. Installation problems - Problem descriptions and solutions.
29. Technical Specifications 29.1 Digital Inputs SPDIF - AES/EBU • 1 x RCA, transformer-balanced, galvanically isolated, according to AES3-1992 • High-sensitivity input stage (< 0.
29.3 Digital • • • • • • • Low Jitter Design: < 3 ns external clock, < 1 ns internal clock Internal sample rates: 32 / 44.1 / 48 / 88.2 / 96 kHz Supported sample rates through word clock: 28 kHz - 103 kHz Internal resolution: 24 bit Input PLL ensures zero dropout, even at more than 40 ns jitter Bitclock PLL for trouble-free varispeed ADAT operation Ground-free digital inputs and outputs 29.
30. Technical Background 30.1 Lock and SyncCheck Digital signals consist of a carrier and the data. If a digital signal is applied to an input, the receiver has to synchronize to the carrier clock in order to read the data correctly. To achieve this, the receiver uses a PLL (Phase Locked Loop). As soon as the receiver meets the exact frequency of the incoming signal, it is locked. This Lock state remains even with small changes of the frequency, because the PLL tracks the receiver's frequency.
30.2 Latency and Monitoring The term Zero Latency Monitoring has been introduced by RME in 1998 for the DIGI96 series of audio cards. It stands for the ability to pass-through the computer's input signal at the interface directly to the output. Since then, the idea behind has become one of the most important features of modern hard disk recording.
30.3 DS - Double Speed When activating the Double Speed mode the HDSP 9652 operates at double sample rate. The internal clock 44.1 kHz turns to 88.2 kHz, 48 kHz to 96 kHz. The internal resolution is still 24 bit. Sample rates above 48 kHz were not always taken for granted, and are still not widely used because of the CD format (44.1 kHz) dominating everything. Before 1998 there were no receiver/transmitter circuits available that could receive or transmit more than 48 kHz.
30.4 AES/EBU - SPDIF The most important electrical properties of 'AES' and 'SPDIF' can be seen in the table below. AES/EBU is the professional balanced connection using XLR plugs. The standard is being set by the Audio Engineering Society based on the AES3-1992. For the 'home user', SONY and Philips have omitted the balanced connection and use either Phono plugs or optical cables (TOSLINK). The format called S/P-DIF (SONY/Philips Digital Interface) is described by IEC 60958.
31.
