Prism Sound Orpheus

The Prism Sound Orpheus is a FireWire interface for personal recording and sound production, for professional musicians, songwriters, engineers and producers. Orpheus is ideal for music and sound recording, production & monitoring, stem-based mastering and analogue summing.

Orpheus provides Prism Sound's renowned performance and sound quality in a dedicated FireWire unit compatible with Windows XP & Vista and MAC OS X 10.4x (Intel & PPC).

Orpheus has line, microphone and instrument inputs, good foldback and stereo or surround monitoring capabilities, ADAT and SPDIF digital I/O plus support for external MIDI devices. Microphone inputs include MS matrix processing and high-performance digital sampling-rate conversion (SRC) is available for digital inputs or outputs.

Orpheus signal path
Eight analogue input channels and up to 10 digital input channels are available (SPDIF on RCA/coax plus ADAT optical) as DAW inputs through the host's audio driver. Similarly, eight analogue output channels, up to 10 digital output channels and stereo headphone outputs can play 22 different channels. For low-latency foldback or monitoring to headphones or main outputs, each output pair (1-2, 3-4 etc) can be driven with an individual local mix of any selection of inputs through the controller applet. All inputs are electronically balanced with automatic unbalanced operation. Outputs are electronically balanced with 'bootstrapping', i.e. level is maintained if one leg is grounded.

The Prism Sound Orpheus Features:

• No-compromise, full Prism Sound audio quality
• Dedicated FireWire interface
• ASIO and WDM drivers provided for Windows XP and VISTA
• Directly compatible with CORE AUDIO on Mac OS X 10.4+ (Intel & PPC)
• Eight "Prism Sound" AD and DA channels, plus SPDIF, ADAT & headphones
• Four high-end integrated mic preamps (typ.-130dBu EIN), switchable phantom
• MS Matrix processing on mic inputs
• Two instrument inputs
• Prism Sound "Overkillers" on every channel to control transient overloads
• Fully-floating (isolated) balanced architecture for optimum noise rejection
• Mono or stereo input configurations
• Outputs arranged as stereo pairs, each with individual mixer
• Low-latency "console-quality" 8-bus digital mixer for foldback monitoring
• Fader, pan, cut, solo on every mixer channel
• Dual headphone outputs each with its own front-panel volume control
• Front-panel master volume control, assignable to selected channels
• Configurable for stereo, 5.1 or 7.1 or surround monitoring
• Built-in sample rate conversion (SRC) on DIO channels
• Prism Sound 4-curve SNS noise shaping on digital outputs
• State-of-the-art clock generation with proprietary hybrid 2-stage DPLL MIDI in/out ports
• Includes Thunderbolt adapter

No-compromise, full Prism Sound audio quality
Orpheus makes no compromises on audio quality. It is the result of years of research and development into digital audio conversion and extensive dialogue with Prism Sound's customers.

Orpheus The Orpheus design brief was: Get Prism Sound quality conversion and mic preamps into a 1U box at a more accessible price point. Sound quality just wasn't negotiable. Orpheus has the same no-compromise analogue front and back ends, with the same fully-balanced-throughout architecture, the same isolation barriers protecting the analogue from digital and computer interference.

Orpheus draws on Prism Sound's years of experience in developing digital audio products, including its range of audio test equipment, adopted by a wide variety of clients across the audio industry from pro-audio to consumer electronics. This experience means that Orpheus is well-behaved both as a computer peripheral and an audio processor.

Reliability is vitally important in professional recording. Prism Sound has always made extensive use of precise software calibration techniques in its converters - pots and tweaks are always unreliable, so there are none.

The design team has gone to great lengths to minimise noise and interference, in particular hum. All of the analogue circuits have galvanic isolation, while the unit's electronically balanced I/O allows it to handle common mode interference sources as well as enabling trouble-free connection to unbalanced equipment.

It is often said that THD+N figures do not always correlate well with the perception of sound quality and this is true - partly because the traditional measures of THD+N or SINAD expressed as RMS figures are rather a broad measure. With this in mind, we have taken great care to make sure that not only is the Orpheus noise and distortion spectrum beyond reproach, but the RMS distortion result measures up to the state of the art.

Standards compliant FireWire interface
Increasing standardisation is leading to more choice for those wishing to "mix and match" editing and production software with various audio interfaces. Prism Sound has taken on board the increasing importance of native processing power for professional users and the fact that software products for standard PC and Mac platforms have been greatly enhanced in recent years.

Prism Sound is probably best known for A/D and D/A converters, not least the ADA-8XR, which already provides a solution for those needing a FireWire interface. However, the flexibility and versatility of the ADA-8XR comes with a higher price tag, reflecting the fact that no other interface provides such exceptional audio performance or can work directly into Pro Tools Core/Processing cards, as well as running a concurrent DSD processor or FireWire interface.

The solution was to create a unit that is dedicated as a FireWire interface and is compatible with Windows PC and Apple Mac computers.

Orpheus is easy to connect to your computer and to your outboard gear. For Windows XP or Vista users ASIO and WDM drivers are provided, while for Mac OS X 10.4 or later, Orpheus interfaces directly to Core Audio. For both Mac and PC platforms, there is a controller application to configure the unit and control its built-in mixer and other functions. Aside from the monitor and headphone level controls, everything else is operated solely from the Orpheus controller application. The controller software opens on-screen as a separate panel alongside your existing editing software.

Orpheus Flexible Inputs and Outputs
Our customers told us that, along with FireWire connectivity, many professional users wanted a highly integrated solution with instrument and microphone inputs, and line outputs that could be used for stereo or multi-channel monitoring and/or foldback to performers. Orpheus offers eight analogue recording channels, eight monitoring outputs, stereo digital input and output on a phono connector plus concurrent optical digital I/O ports that can interface to S/PDIF or ADAT data formats, giving Orpheus a maximum capability of 18 concurrent input and output channels plus stereo headphones.

Orpheus' eight analogue inputs support various capabilities. Orpheus has four really good mic amps with software-controlled gain in 1dB steps, individually-switchable phantom power - and very low noise and distortion. These inputs are auto-sensing, and support microphone and line input, with digitally-controlled mic gain in excess of 60dB. Two of these inputs also support direct injection (DI) instrument connections with quarter-inch jacks on the front panel. RIAA Equalization can be selected in the controller applet on channels 1 & 2 so that turntables can be connected for archiving or sampling applications. By selecting the input type (Mic or DI) , low- or high-impedance cartridges can be loaded with suitable termination impedances. All inputs have individually-selectable Prism Sound "Overkillers" built in, just as on the higher-priced ADA-8XR, to catch those fast transients. The Overkiller threshold automatically follows the operating line-up level selection (+4dBu or -10dBV). Overkillers are ideal for percussive sounds, particularly drums, where headroom can be a problem.

The co-axial digital I/O port can be switched in the Orpheus controller applet between S/PDIF and AES3 formats. This control changes the operating voltage and the Channel Status format and is complemented by two in-line adapter leads that provide external XLR connections for AES3 devices. Other connections include MIDI in and out and wordclock sync I/O.

Orpheus can also operate in a stand-alone mode using its ADAT or co-axial digital I/O connections. Once set up using the Orpheus controller applet, the unit can be disconnected from the host computer and used independently. Orpheus will retain its settings when powered down so even if it is switched off, Orpheus can be re-powered and stand-alone operation can continue with the automatically-stored settings.

Digital Mixer
Our customers also identified a need for a unit that could provide low latency foldback to performers, particularly when tracking and overdubbing. In answer to this need, Orpheus has a powerful built-in digital mixer that can be configured from the host computer to provide foldback feeds to performers, each with their own stereo mix of workstation playback and any of the inputs.

The question of latency in computer interfaces, especially USB and FireWire boxes, is an important one. Obviously there are situations where the round-trip latency needs to be really short, like in overdubbing. The problem is that even if the latency on the interface and in the driver is as short as it could ever be, a native DAW is busy with plug-ins and other software and buffer times are probably set long. The only answer is to provide local foldback mixing in the interface. This is not new, and other products feature it, but most local mixers in competitive products are just too basic. Orpheus provides 'console quality' local mixing - every output has its own independent mixer, with channel strips for all inputs and workstation feeds, complete with fader, pan/balance pot, solo and mute buttons, and full metering. Strips can be stereo or mono, and the mixes are dithered with filtered coefficients, just as in a top-end digital mixer.

There is a very small residual delay through the A/D and D/A conversion process in the foldback path, mostly from filters used for decimation and interpolation. However, with the low-latency Prism Sound DSP mixer, the worst-case delay through the A/D and D/A path is only 0.5ms and is significantly less at higher sampling rates. This is generally reckoned to be small enough not to be problematic.

Although the unit's outputs will mainly be used for monitoring or foldback, the fact that they are of such high quality makes them suitable for a range of other applications such as insertion points, analogue summing or stem-based mastering.

Orpheus Flexible Monitoring
Professional users demand more sophisticated monitoring capabilities and are getting used to surround sound with HDTV and DVD, so it is becoming important to support surround monitoring setups.

As well as wanting great analogue recording channels, the DAW user also needs top-quality monitoring. The eight analogue outputs on Orpheus allow monitor setups from multi-stereo up to 7.1 surround. Orpheus has a real volume knob which can be assigned to any or all of the analogue or digital outputs for use as a control room monitor control. There are two headphone amps, suitable for all types of headphones, each with its own independent volume control. As well as having its own workstation feed and mixer, the headphones can also be quickly switched across the other output pairs, which is handy for setting up.

Sample Rate Conversion and Noise Shaping
The digital output is equipped with the four Prism Sound SNS noise-shaping curves and includes Prism Sound's renowned synchronous sample-rate conversion, allowing outputs to various external devices at other sampling rates. The sample-rate converter can be used at the outputs as well as the inputs, so as well as dealing with unsynchronized or wrong-rate digital inputs, Orpheus can also generate, say, a live 44.1kHz output from a 96kHz session. Since Orpheus also includes the full suite of the famous Prism Sound 'SNS' noise shapers, you can also reduce to 16-bits at mastering-house quality.

Unsurpassed Jitter Rejection
In the 1990s Prism Sound pioneered testing of sampling and interface jitter and as a result our digital audio products deliver unsurpassed jitter rejection. Prism Sound digital audio products lock up fast and re-generate ultra-stable clock outputs. Another aspect of the traditional Prism Sound converter that is retained was the clocking - it's just as important as analogue-path considerations sound-wise. So whether it's providing a high-quality master clock for the rest of the room, or dealing with a jittery clock from outside, Orpheus is as rock-steady as its forbears.

Support
Over the years, Prism Sound's reputation for audio quality has been matched by its reputation for after-sales support and technical advice. Orpheus has the benefit of that support and customers have access to one of the best technical teams in the business.

The Last Word
We believe that Orpheus delivers exactly what our personal studio customers have asked for - all the performance of a Prism Sound product in a dedicated FireWire unit that handles line, microphone and instrument inputs with good foldback and monitoring capabilities, yet at a more accessible price tag. We are confident that customers using the new Orpheus converter will agree that it sounds as good as it looks.