KALLIOPE (a.k.a. Calliope, meaning “beautiful voice”) is the eldest of the Muses, goddesses of music, song and dance in Greek mythology. Kalliope is the goddess of epic poetry and eloquence.
In any audio system, there are certain points along the signal path that are more crucial than others. These are the intersections where the signal is converted from one form of energy into another. Such transformations occur when the needle of a phono cartridge traverses the micro-grooves of a vinyl record, converting kinetic energy into an electrical signal. At the opposite end of the signal path, loudspeakers must transform electrical input into acoustic output.
But perhaps the most critical transformation of all is the conversion of the output of digital sources into an analogue signal, ideally without loss or distortion of any kind. Despite the lofty claims of many manufacturers, what is lost or changed at this point can never be recovered or restored.
In acknowledgment of the on-going refinement of digital audio sources and the rapid evolution of high-resolution digital audio formats, Gryphon Audio Designs now presents the Gryphon Kalliope digital to analogue converter to stand as the gateway that conveys the musical signal from one domain to the next in utterly pristine condition.
Three Reasons Why Bits Are Not Just Bits
The well-worn phrase “Bits is bits” encapsulates the widespread misconception that any reasonably constructed digital system will result in “Pure, Perfect Sound Forever,” in the lamentable promotional slogan coined by the inventors of the compact disc.
1.) Digital audio is not a simple one-dimensional row of numbers, where all that is required is to keep the correct numbers in the correct order. In fact, it is a data stream of numbers flowing through time. And the right number at the wrong time is (almost) as bad as the wrong number.
Gryphon Kalliope ensures effective correction/prevention of timing errors (jitter) using sophisticated circuit topology and exclusive, custom-built components.
2.) Following digital to analogue conversion, an analogue filter is required to remove high frequency noise. The deleterious side effects of a typical steep-slope “brickwall” filter include temporal smearing, energy loss, compromised resolution and reduced transparency.
Gryphon Kalliope employs advanced technologies and an innovative, minimalist single-component filter with no adverse audible impact.
3.) Advocates of the “bits is bits” attitude tend to ignore the fact at the end of all digital signal processing there is an analogue stage. The circuit design, component selection, power supply and layout of this stage are all just as critical now in the digital era as they ever were in the analogue age.
Gryphon Kalliope draws on decades of experience in the design and construction of some of the finest analogue audio systems the world has ever known.
Kalliope is far from Gryphon’s first foray into the digital arena. Throughout the digital era, Gryphon Audio Designs have stood for major innovations, paving the way for others to follow. In 1998, Gryphon introduced the world to the sonic benefits of 88.2 kHz asynchronous sample rate conversion in the CDP-1 CD player, the world’s first implementation of this advanced technology.
Gryphon Adagio, launched in 2001, and Gryphon Mikado, released in 2003, upgraded to 24-bit/96 kHz asynchronous sample rate conversion, preserving linearity for vastly reduced distortion and noise.
In 2008, the celebrated Gryphon Mikado Signature CD player took our cornerstone philosophies of dual mono and fully symmetrical balanced operation where no one had gone before - into the digital domain, employing two stereo DAC’s per channel in full dual differential mode running 32-bit/192 kHz. This configuration drastically lowers the digital noise floor and contributes to the expansive soundstage and sharply focused stereo image of digital audio by Gryphon.
Now, with selectable 32-bit/210 kHz asynchronous sample rate conversion and a dedicated ESS SABRE ES9018 32-bit D/A converter per channel, incorporating eight individual D/A converters in Dual Differential coupling, the Gryphon Kalliope DAC builds on the brand’s unique heritage and continues to lead the way.
Stability and Control
Gryphon Kalliope reaps the full benefits of Gryphon’s uncompromising design philosophy, including strict dual mono configuration, minimal internal wiring, fully isolated separate power supplies for analogue, digital and control/display circuitry and exclusive, custom components such as precision crystal oscillators and toroidal transformers.
To ensure unlimited, pure power to all stages, transformer windings for digital and analogue sections are physically separated and the four-layer printed circuit board employs a 70 mm copper trace to ensure optimal grounding and power distribution as well as signal transfer.
For maximum control and stability, each analogue channel in Gryphon Kalliope employs a dedicated custom-built 65 VA toroidal transformer and 34,000 microFarad power capacitor banks. Built from the finest discrete components, Kalliope eschews capacitor banks based on a few large capacitors, in favour of parallel-coupled clusters of smaller, high-performance caps (a total of 28), for lower equivalent series resistance.
Kalliope’s substantial, heavily regulated high-current power supplies would not be out of place in a typical integrated amplifier.
Direct Stream Digital
In addition to PCM sources all the way up to 32 bits and 384 kHz sampling frequency, Gryphon Kalliope is among the select few digital to analogue converters that is fully compatible with the DSD (Direct Stream Digital) audio format.
Unlike the mainstream PCM (Pulse Code Modulation) standard employed for CD, WAV files, etc., DSD employs Pulse Density Modulation and a sample rate of up to 6.144 MHz.
DSD was the core of the now largely dormant Super Audio CD format, but lives on in the form of an ever expanding library of downloadable audio files widely regarded as the highest resolution presently available to the consumer.
Note: DSD files on an SACD cannot be accessed for playback via an external DAC due to copyright protection issues.
For convenience and intuitive ease of use, Gryphon Kalliope’s functions can be accessed via remote control or soft-touch buttons on the front panel: On/Standby, Mute On/Off, Input Selection, Digital Filter selection, Sample Rate Conversion On/Off, Phase +/-. The remote also includes adjustment of display brightness (100%, 75%, 50%, 25%, Off).
For PCM playback, a fast or slow linear phase non-dispersive digital filter can be selected. For DSD playback via USB, a 50, 60, or 70 Hz Infinite Impulse Response (IIR) digital roll-off filter can be selected.
Kalliope is fitted with a phase inverter, because some source components, power amplifiers and even recordings may inadvertently invert the phase of the signal. Kalliope allows the owner to correct this error while seated at the main listening position.
The Kalliope front panel menu provides control of additional features, including naming of sources, default display brightness, word clock synchronization for use with an external word clock, output attenuation of 0 dB (Off) or -6 dB to match levels to other sources and a user-selectable Auto Standby mode that can be set to force powerdown after 30 minutes, 60 minutes, 2 hours or 4 hours. A Reset function immediate restores all default settings.
The easily legible Vacuum Fluorescent Display provides confirmation of current settings.
In addition to carefully executed, galvanically isolated digital inputs (three 75 Ohm BNC and one 110 Ohm XLR) to minimise jitter and noise, Gryphon Kalliope is also fitted with a 110 Ohm XLR digital output which makes the de-jittered signal from the selected input available to other equipment.
Gryphon Kalliope eliminates phono plug S/PDIF connections, because the BNC connector is the only way to ensure a true 75 Ohm impedance for optimal data transfer.
For increasingly popular computer music sources, Gryphon Kalliope incorporates a state of the art, bit-perfect, asynchronous and galvanically isolated USB input, capable of full 32-bit/384 kHz data transmission. Because Kalliope is a native Class Two USB device, simple installation of appropriate drivers is necessary for PC users. Drivers are pre-installed on Macs.
Music playback via conventional synchronous USB is a one-way connection that uses the computer’s bus frame rate as its clock source, resulting in highly unstable timing. Adaptive USB is marginally better, as it allows the receiver chip to adapt to the drifting signal by constantly adjusting its own frequency. However, both methods introduce substantial levels of jitter.
With asynchronous USB transfer mode (unrelated to asynchronous sample rate conversion), the Gryphon Kalliope master clock is not synchronized to a clock in the computer. Instead, the Kalliope’s high-precision internal clock controls the data stream from the computer to a buffer near the DAC, eliminating a major source of timing errors.
Input signals sync to one of two clocks depending on the signal’s sample frequency, a 22.5792 MHz clock for multiples of 44.1 kHz and a 24.5760 MHz clock for multiples of 48 kHz. Operating at true multiples of the signal’s original sampling frequency ensures far more accurate timing.
While Gryphon Kalliope is fitted with a 75 Ohm BNC connector for optional synchronisation via an external word clock signal, the Kalliope’s internal, independent, specially designed, temperature-compensated crystal oscillators with accuracy better than 5 parts per million address crucial timing issues so effectively that its superb clock-extraction circuitry removes all traces of clock jitter and other clocking artefacts.
Asynchronous Sample Rate Conversion
Gryphon Kalliope offers the owner the option of upsampling PCM sources with a native resolution of up to 32-bit/192 kHz to 32-bit/210 kHz. Clock rate conversion up to 40 MHz in the DAC minimises jitter and eliminates the need for steep-slope analogue filtering, shifting aliasing noise upward in frequency for zero impact in the audible range, for an effectively transparent filter function.
Gryphon Kalliope employs state of the art algorithms to execute these complex mathematical calculations with extreme speed and precision.
While sample rate conversion cannot restore lost information nor generate new information, properly executed sample rate conversion in the Gryphon Kalliope does create optimal working conditions for digital and analogue circuits, allowing them to more accurately reproduce all the information that is available.
The sample rate conversion process allows the implementation of a non-invasive, gentler, simpler, high quality analogue filter consisting of a single silvered Mica capacitor with high slew rate and tight tolerances. Separate filters are used for PCM and DSD.
As a direct result of the removal of high-frequency aliasing distortion, the integrity of the audio signal is uncompromisingly maintained with a noise floor well below that of the recording itself.
Dual Differential DAC Topology
As noted earlier, Gryphon pioneered the use of multiple DAC’s configured in a Dual Differential topology with separate regulated power supplies. In addition to true balanced operation, this solution yields perfect channel separation, greatly improved out-of-band noise suppression and significantly enhanced dynamic range.
The clearly audible result is music that emerges naturally and effortlessly from a silent, black background.
After comprehensive listening sessions to seek out the best available digital-to-analogue conversion technology without regard to cost or other extraneous considerations, Gryphon equipped the Kalliope with the most sophisticated digital to analogue conversion available today.
The final analogue stages are based on carefully selected fully discrete components of the highest quality.
Gryphon Kalliope is built to extract the very best from present and future digital audio sources from the humble CD to wideband, high-resolution DSD and PCM files.
Cutting Edge Digital Prowess
With a vigilant eye on the rapid evolution of the state of digital technology, Gryphon Kalliope is built to be future-proof with modular digital audio sections that allow practical upgrading, as the opportunity arises.
The consummate build quality, engineering, mechanical integrity and functional elegance of the Gryphon Kalliope can only hint at the musical glories that await from this musical instrument designed solely to preserve the integrity and purity of the original musical event.
To experience what mere words cannot communicate, you are cordially invited to visit your nearest authorised Gryphon Audio Designs showroom for a demonstration of the cutting edge digital prowess of the Gryphon Kalliope.
Copyright © 2013 Gryphon Audio Designs