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Orpheus Operation Manual by Ian Dennis This manual is also available as 'on-line help' from the Orpheus Control Panel applet. You can access the on-line help from the 'Help' button in the top right-hand corner of the applet.
Table of Contents Part 1 General information Part 2 Introduction to Orpheus Features ..........................6 System requirements ..........................7 About this manual ..........................7 Part 3 Quick start guides Quick start for Mac ..........................10 Quick start for Windows ..........................10...
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Input Setup tab ............................... Output Setup tab ............................... Mixer tabs ............................... ADAT tab ............................... Orpheus drivers ..........................40 Part 7 Technical topics Stability and latency ..........................42 Clocking and jitter ..........................43 Dither and noise-shaping ..........................45 Analogue interconnections ..........................48...
Email: tech.support@prismsound.com Web: http://www.prismsound.com Or contact your local Prism Sound distributor as detailed on the website. WARNING! TO PREVENT FIRE OR SHOCK HAZARD DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE. DO NOT REMOVE THE COVER. NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
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Prism Sound Orpheus Operation Manual Revision 1.05 Statements of conformity This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against interference in a residential area.
MIDI interface as well as a host of advanced synchronization and monitoring facilities. In short, Orpheus is intended to provide 'studio in a box' functionality for the digital audio workstation (DAW) user. That's not so unusual - there are many other interfaces on the market which provide similar functionality.
The printed version of the manual is also provided in 'electronic' format, as a 'pdf' file, on the Orpheus software disc. The pdf file can be viewed and printed using the Adobe Acrobat Reader, which can be downloaded free at www.adobe.com.
WDM audio ports, and a bidirectional MIDI port. Note that only the first two ADAT ports (if enabled by the Orpheus Control Panel applet) are visible in the WDM case. NOTE: Do not connect the Orpheus unit to the FireWire port of the PC until instructed to do so during the installation process.
The full installation procedure is as follows: · Connect your Orpheus to the mains supply with the power-cord provided. DO NOT connect it to the Mac yet. · Insert the installation disc into a DVD-ROM drive on your Mac.
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· You may need to enter an administrator's name and password. Click 'OK': · The installation process will then complete: · When software installation is complete, close the box and connect the Orpheus unit to the FireWire port of the Mac.
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Prism Sound Orpheus Operation Manual Revision 1.05 routine Tiger online update process. A copy of the patch can be found on the Orpheus installation disc. Before installing the patch, ensure that your Mac has been updated to at least version 10.4.11. This should happen automatically if online updates are enabled.
Windows PC. You must have Windows XP, Vista (32-bit) or later, and a spare FireWire 400 (IEEE1394A) port. · Connect your Orpheus to the mains supply with the power-cord provided. DO NOT connect it to the PC yet.
Operation Manual Revision 1.05 · During installation, you will be prompted to connect the Orpheus to the FireWire port of the PC. Do so, then click 'Next': The Orpheus device's ports should now be visible to Windows and any applications as both ASIO and WDM audio ports, and a bidirectional MIDI port.
The figure above is a simplified block diagram of the Orpheus audio signal paths. Orpheus is basically a sound card, with all inputs made available to the host computer via the FireWire bus, and all outputs likewise driven from the FireWire bus. However, Orpheus' signal paths contain a range of enhanced processing and mixing functions, which are described in the following sections.
Note that there is no explicit stereo width control provided in the matrix; however width can be adjusted by balancing the gains of the mid and side inputs - the gain steps of the Orpheus microphone preamplifiers are fine and precise. In line input mode, no fine gain adjustment is available, so if the Orpheus MS matrices are used with external preamplifiers, these must have fine and accurate gain control if width adjustment is required.
In normal operation, the eight analogue outputs are fed directly with individual signals from the host PC or Mac; however, it is possible to feed the outputs from local digital mixers within the Orpheus hardware if desired - this is described in the Output mixers section below.
5.1.4.3 DO synchronization Note that it is necessary to ensure that the sample clock of any digital audio device to which Orpheus' digital outputs are connected is synchronous with Orpheus' own sample clock. This is usually achieved by synchronizing the receiving equipment to Orpheus' S/PDIF, ADAT or Wordclock output, but can be achieved by synchronizing Orpheus to the receiving device's clock or house sync (by setting DI or Wordclock as Orpheus' sync source).
Second, the headphone outputs cannot be assigned to the assignable gain control. This is because they already have dedicated volume controls on the front panel. 5.1.8 Metering system Orpheus' front panel meters can meter the level of either inputs or outputs as selected in the Unit Settings tab of the Orpheus Control Panel applet.
In the former case, the SRC simply converts any incoming digital signal of whatever sample rate to the sample rate of the Orpheus system. But if the SRC is in the digital output, it is necessary to specify what the output sample rate must be. Furthermore, it may be necessary to lock the output rate to an arbitrary external reference.
· Standby button: puts the unit into a low-power standby state. Note that the FireWire interface is still active in standby mode, so the Orpheus unit can still be recognised by the host, although its inputs and outputs are inactive. The LED in the standby button flashes to identify the unit in multi-unit setups when the 'Identify' button in the Control Panel applet is clicked.
S/PDIF output (if lit when the meters are in output mode. Rear panel Orpheus' rear panel contains all Orpheus' connections, except for the instrument inputs and headphone outputs, which are on the front panel. From left to right (viewed from rear): ·...
It is possible to operate Orpheus without a FireWire connection to a host computer. This is done by setting up the unit as required using the Orpheus Control Panel applet whilst it is connected to a host computer via its FireWire interface, then placing the unit in standby by pressing the standby button, before disconnecting the unit from the host and power source.
The hub can be initially raised with a small flat-bladed screwdriver. Retain the feet for later use. If Orpheus units are rack mounted, an empty 1U gap should be left above each Orpheus to ensure effective cooling.
Orpheus Control Panel. Accessing the Orpheus Control Panel The Orpheus Control Panel can be run directly like any other Mac or Windows program, or it can be accessed from the operating system itself, from the "Sound and Audio devices" dialogue in the Windows' Control Panel (or from the Device Manager) or from the Audio MIDI Setup in Mac OS X.
Unit Settings Global Settings. Unit Settings are applied only to the Orpheus unit which the Control Panel is currently assigned to control, whereas Global Settings apply to all connected Orpheus units as a whole. The upper area also contains buttons for...
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NOTE: It is not possible to change the sample rate in a Windows system whilst any of Orpheus' ports are in use in WDM mode. In this case it is necessary to disconnect the ports from the application before changing the sample rate.
UNLock and ASNC indicators are provided. UNLock is lit when no S/PDIF carrier is detected at the selected input; ASNC (asynchronous) is lit when the incoming carrier is not locked to Orpheus' selected sync source. All inputs have high-resolution peak metering, with overload indication 0.05dB below clipping;...
('DAW') or from a dedicated low-latency foldback mixer ('Mixer'). Each stereo mixer can mix any of Orpheus' analogue or digital inputs to the output pair, along with the DAW feed, as described in the following section. The headphone output pair has a third 'Bus' setting which allows it to monitor any of the other output pairs using the row of headphone bus radio buttons.
It is not necessary to run the Orpheus Control Panel applet for applications to be able to use Orpheus; however, the applet is needed if any but the most basic control of Orpheus' functions is required.
Revision 1.05 Technical topics The following sections contain detailed discussions of various relevant technical issues. The content of these sections is not required to operate Orpheus, but is provided merely as background information. Stability and latency Since audio production has found its way inside the computer, new problems concerning issues of stability and latency have arisen.
Operation Manual Revision 1.05 In the case of Orpheus, problems of latency and stability are improved by a couple of useful features: First of all, the operator can control the buffer delays within the Mac and Windows drivers directly, irrespective of what buffering is employed by the user's particular audio software. It is generally recommended that these buffer delays are set long, in order to provide best stability.
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Prism Sound Orpheus Operation Manual Revision 1.05 But why is clock jitter so important? Analysis of sampling jitter Analysis of sampling jitter (small variations in the sampling intervals of an A/D or D/A converter) shows that it produces a similar effect to phase modulation, where distortion components appear as ‘...
Orpheus and CleverClox Orpheus is designed to source clocks which are as stable and accurate as possible, and also with the aim of being insensitive to the quality of incoming clocks. It is designed to remove jitter from any selected reference sync source before it is used as a conversion timebase, so as to eliminate any audible effects of sampling jitter, whatever sync source is used.
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Orpheus provides a comprehensive choice of dithering and noise-shaping processes. These comprise ‘flat’ dithering, plus a selection of four Prism Sound ‘SNS’ (‘Super Noise Shaping’) algorithms. All produce high-quality 16 bit output: the choice of which one to use is purely subjective.
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SNS2 is a good starting point for most situations. The Prism Sound SNS logo shown above is found on many of the world’s finest CDs, and is recognised as a standard of technical excellence. The logo, and accompanying sleeve note, is available by contacting sales@prismsound.com.
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This is especially true for jacks, where unreliable tip connection can owing to the slightly non-conforming shape of some manufacturers' parts. Neutrik connectors are used in Orpheus, and these are recommended to ensure reliably-mating cables.
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(the outer of the instrument input jacks, or pin 1 of the mic input XLRs). Since no dedicated terminal exists on Orpheus, it is usually easiest to connect the wire to the outer of one of the deck's unbalanced output connectors. In some situations, a direct connection to local mains ground may work better.
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Prism Sound Orpheus Operation Manual Revision 1.05 · Ensure that signals passing between equipment do so at as high a level as is practical; · If switching interference is heard, try to identify the source equipment by unplugging things one by one.
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Prism Sound Orpheus Operation Manual Revision 1.05 Analog Line Inputs Electronically balanced, with fully-balanced analog signal path Configuration: Input sensitivity: Switchable ‘+4dBu’ (0dBFS=+18dBu) or ‘-10dBV’ (0dBFS=+6dBu) 14.5kR Input impedance: Unbalanced mode: Automatic -117dB (0.00014%, -0.1dBFS) Total harmonic distortion: THD+n: -111dB (0.00028%, -0.1dBFS)
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Full implementation, Consumer (S/PDIF) or Professional (AES3) Channel Status: Word-length: 24 bits, or reduction to 16 bits using flat TPDF dither or Prism Sound SNS (Super Noise-Shaping - four alternative shapes available) Via S/PDIF RCA, using RCA-XLR adapter (supplied) AES3 operation: Selectable at S/PDIF output;...
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Prism Sound Orpheus Operation Manual Revision 1.05 Except where otherwise stated, audio performance data are typical, RMS, unweighted, 20Hz..20kHz figures, measured at 997Hz, using fs=96kHz and '+4dBu' sensitivity settings. In keeping with our policy of continual development, specifications are subject to amendment without notice.
Index - D - Delay Device Manager - 2 - DI synchronization DI unlocked indicator 256x clock Digital inputs 23, 38 Digital outputs 25, 38 - A - Dither 25, 45 DO synchronizarion ADAT 27, 40 Drivers ADAT control ADAT Direct mode - E - ADAT input ADAT outputs...
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10, 12, 34 Phase-reverse Manual Phono cartridges 23, 48 Maximum number of channels Prism Sound, CleverClox Meter panel Prism Sound, SNS (Super Noise-Shaping) Meters Mic inputs 22, 38 - Q - Microphone preamplifiers Mixer controls Quick start guide, Mac Mixers...
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