The apparent simplicity of the Emerson actually hides a complexity and a finesse far greater than it seems. From the choice of the internal components to the embedded software, each step of the development process has been crucially thought through to enhance the listening experience.
The philosophy implemented in the Emerson is that of the straight wire: no sampling frequency conversion or data processing is applied, apart from volume control when used. The data are transmitted directly to the S/PDIF and AES/EBU modulators of the Emerson DIGITAL, or respectively to the digital-to-analog conversion chip in the case of the Emerson ANALOG.
This concept considerably complicates the software management when changing the type of stream on the fly, especially to ensure silent switching. Such a solution guarantees a neutral restitution, without any coloration.
Both Emerson models leverage Engineered's streaming engine, a proprietary solution based on a Sitara processor from Texas Instruments.
The embedded software, which handles the various network communication protocols and audio stream decoding, has been under continuous development for many years. Internal processes have been optimized to ensure audio data integrity, support for Hi-Res file formats (PCM and DSD), and a smooth and responsive user experience.
Two clock generators are used alternately, depending on whether the track being played back is sampled at a base frequency of 44.1kHz or 48kHz (as well as any multiples thereof). The Emerson streamers do not include a variable oscillator or a synchronization loop. The stream of audio data is therefore directly cadenced by the active clock.
Additionally, the selected oscillators offer superlative performances, with extremely low phase noise in the audible bandwidth (below -135dBc/SQR(Hz)). The distribution of the clock signals has been carefully designed to minimize jitter throughout the digital audio signal path.
The Emerson DIGITAL uses two separate modulators for the S/PDIF output and the AES/EBU output. This is the only way to meet the specifications of both standards without having to make compromises. High-speed output stages, synchronized by the main clock to avoid jitter, and the best transformers on the market ensure two independent isolated outputs and a perfect rejection of common mode problems for superior performances.
For the Emerson ANALOG, a DAC from Cirrus Logic was chosen. This is a well-proven integrated circuit capable of impressive playback quality when optimally implemented. Its power supply, output stages topology and filter circuits required a lot of adjustments, measurements and listening before validating the final solution in accordance with the product philosophy.
The quality of the power supply for sensitive electronic circuits is a decisive factor for a device of this type. Once again, a close attention has been paid to the selection of the components and topologies. The choice of using an external adapter offers the advantage of keeping the mains voltage away from the core of the device. The DC voltage supplied to the Emerson by the external power supply is smoothed by a series of common and differential mode filters and then delivered to the various components of the electronic board. Each critical section of the circuits benefits from a dedicated filtering and voltage regulator to avoid undesirable interactions.
Finally, the power supplies for the clock generators, the synchronization circuits and the analog section are particularly efficient, with an extremely low electrical noise, less than 1µV RMS (measured in a frequency bandwidth from 10Hz to 100kHz).