COS Engineering is founded by three close friends who are serious about audio entertainment. With an aversion to cacophony, an aspiration for style and a penchant for simplicity, we harness extensive knowledge and experience in mathematics, electronics and communication to research and design. The objective is to offer gears featuring musicality as well as aesthetics. D1, COS Engineering’s first product, makes its debut in 2014.
C O S D 1 mkII
D1, a dapper unit in cool aluminum, is a fusion of a digital-to-analog converter and a pre-amplifier. It is capable of rendering crystal clear, spacious and dynamic music and meets the demand of those with willing and fastidious ears.
STYLISH DESIGN
The exterior of D1, composed of aerospace grade aluminum alloy which seals off electric and magnetic interference from outside, is crafted finely to embody a structure of straight lines and a single circle.
ALGORITHM AND DSP
COS’s proprietary algorithm with a linear-phase delay FIR filter can up-sample original data to 176.4K or 192K, and this massive computation is handled by a powerful 3648 MMAC/sec DSP.
BUFFER and RE-CLOCKING
D1 stores digital data in a one-second buffer before converting to analog signals, under the coordination of a crystal oscillator with a jitter precision less than 1ps and a dedicated re-clocking circuitry.
DUAL POWER SUPPLY
Two torroid transformers power the digital circuit and the analog circuit separately, thereby eliminating possible interferences.
PARALLEL STRUCTURE WITH TUNING AND MATCHING
The analog circuit bifurcates into two boards to eliminate cross-talk, and the high-performance DAC chips, one on each board running as mono, are manually tuned and matched to attain a lower distortion.
FULLY BALANCED DESIGN
D1’s balanced design ensures that even harmonics match and are gracefully cancelled out. Distortions are low to the extent possible.
VOLUME CONTROL
D1’s volume control is composed of a ladder of high precision resistors and an array of analog switches which are low in resistance, noise, and distortion.
C O S D 2
The D2 is designed to turn digital data into real music. Armed with our proprietary algorithm, it offers a pitch-black background and expansive sound-stage, coupled with colorful, dynamic rendering of instruments and a palpable sense of vocal realism.
COS ALGORITHM AND DSP
COS Engineering’s proprietary algorithm up-samples original data to 176.4K or 192K, 24-bit by a process in an array of 4096 with 32-bit precision. To rule out phase contamination that may stem from the more computationally efficient IIR filter, a linear-phase delay FIR filter is chosen. This massive computation is handled by a powerful DSP capable of 3648 MMAC (millions multiply and add) per second.
BUFFER AND RE-CLOCKING
D2 receives data from digital sources, whether a PC, a CD transport, or a mobile device, aligns them in exact frames with a one-second buffer, and sends them out for interpretation by the COS algorithm. The data so processed is then converted to analog signals, under the coordination of a crystal oscillator with a jitter precision less than 1ps and a dedicated re-clocking circuitry.
POWER
D2 harnesses two selected switching mode power supplies with specially designed circuitry for lower noise. These power supplies work with 100~240VAC; there is no need to select voltage.
FULL BALANCED DESIGN
Balanced designs are applied throughout the entire audio signal path. Even-order harmonics on the differential signal pairs are carefully matched and are thus gracefully cancelled in order to achieve the lowest possible distortions.
GALVANIC ISOLATION
The galvanic isolation between digital and analog circuitries further ensures that the audio signal is not to be contaminated.
VOLUME CONTROL (D2V ONLY)
D2’s volume control is composed of a ladder of +-0.1% high precision resistors and an array of analog switches which are low in resistance, noise, and distortion. No mechanical parts are used. Frequent use does not erode its precision.
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C O S H 1
H1 is an audiophile-grade DAC plus headphone amplifier, featuring COS Engineer’s proprietary digital-to-analogue algorithm. For those who seek acoustic joy through headphones, H1 is a ‘must have’ because of the details and the smooth yet dynamically powerful sound it provides.
COS ALGORITHM AND DSP
COS’s proprietary algorithm with a linear-phase delay FIR can up-sample original data to 176.4K or 192K, and this massive computation is handled by a powerful 3648 MMAC/second DSP.
BUFFER AND RE-CLOCKING
H1 stores digital data in a one-second buffer before converting to analog signals, under the coordination of a crystal oscillator with a jitter precision less than 1ps and a dedicated re-clocking circuitry.
HEADPHONE
4 power amplifiers to accommodate 2 unbalanced headphones or 1 balanced headphone.
POWER
H1 harnesses a selected switching mode power supply with specially designed circuitry for lower noise, and galvanic isolation between digital and analog circuitries are added to prevent audio signals from being contaminated.
VOLUME CONTROL
H1’s volume control is composed of a ladder of high precision resistors and an array of analog switches which are low in resistance, noise, and distortion.
