Tchernov Audio is proud to announce our first consumer electronics product; the Apollo Digital to Analogue Convertor. Having established a reputation for exhaustive research and design coupled with absolute attention to detail in the field of audio cable design, we have now transferred these exacting processes to the creation of truly world class audio equipment. Launching this product is not a decision we have reached lightly. We felt that if would could not meet the standards we have established in our cable construction, this project would not be undertaken and the Apollo only exists because we feel we have been able to bring our expected standards of excellence to its performance. The Apollo is not a ‘me too’ product. Every aspect of its design and construction has been approached with a view to seeking quantitative performance improvements over and above what might be considered ‘acceptable’ by our competitors. By combining exceptionally high quality components with a compromise free approach to their implementation, we believe we have created a product without equal. Beyond its exceptional specification, it has been designed to offer a level of long term listening satisfaction that can often be lacking in sophisticated digital products as well as the pride of ownership that only a device possessing superb craftsmanship can provide. Input interface The Apollo DAC receives digital audio data in two principle format types. The AES simplex data stream (AES/EBU, SPDIF, Toslink) supports PCM data up to 24 bit and 192 kHz sampling frequencies. The USB Audio 2.0 input supports PCM data up to 32 bit and 384kHz sampling frequency andDSD data up to 11.2896 MHz (DSD256) to cover the complete spread of commonly encountered audiophile recordings. The input receiver module ensures a jitter-free recovery of AES and USB audio data by utilizing a special adaptive algorithm of data stream delay and secondary data stream synchronization from a D/A masterclock signal with ultralow phase noise. All digital inputs feature dual galvanic insulation with parasitic capacitance lower than 1pF from the main DAC circuits. D/A converter and masterclock oscillator The D/A Converter is based on the exceptional Asahi Kasei 3d generation DAC ICs “Verita” AK4490 in “dual mono” configuration with independent power supplies – 4 extremely low noise and high stable discrete regulators for each DAC IC. The correlation between the power and reference voltages is specially selected to achieve the lowest distortion level for every DAC IC. The preliminary signal conditioning and control signal generation is performed by a high speed complex programmable logic device (CPLD). All active signal lines are buffered by logic cells with hysteresis input characteristics to achieve the best RF noise immunity. Every logic module is powered via its own LC filter and the groups of similar-function modules have their own low noise regulators. The dual frequency masterclock oscillator is specially designed and implemented to ensure ultra low phase noise and jitter. It is based on super high short-term stability quartz oscillators with a special crystal cut and very high Q Factor. The oscillator is powered through 4th order symmetric RF filter from a very low noise discrete regulator with its own rectifier and separate winding on a power transformer to ensure an optimal performance. As a result of these comprehensive arrangements, the low frequency rms jitter of the masterclock signal does not exceed 60 femtoseconds (0.06 picoseconds!). Analog signal processing The DAC IC’s analog output signals are precisely filtered by individual anti-aliasing Bessel 3½ order filters and processed by 2-stage subtractors to achieve maximum in-phase noise reduction. Every stage of the analog processing utilizes extremely linear and wideband Op Amps. The output is buffered by discrete class A single-ended followers. All analog circuits are made with the use of industrial grade passive components to provide the lowest noise and distortion possible. The OpAmps are powered from 4 independent precise low noise discrete linear regulators (2 per channel). All analogue circuits are powered from a separate power transformer with very low idle current and magnetic losses. Power The rigorously engineered power supply utilizes 3 separate power transformers specially designed and manufactured for Tchernov Audio. The power transformers feature very low magnetic losses and negligible idle current. All transformers are covered by a high loss magnetic shield. The digital and analog power transformers have their own RF power filters. The power rectifiers are based on Schottky diodes and equipped with special circuits to prevent any oscillation processes while diode commutation. The total filter capacitance for all rectifiers and secondary circuits exceeds 70000 uF. A specially engineered soft-start system prevents any excess current pulse when powered on. Service and display At no point do any control and display systems of the Apollo DAC contain microcontrollers with their own clock signals. All control and display functions are performed by CPLDs with totally static structure. This static control system does not generate any noise and exerts no influence on the D/A conversion process and the output analog signal. PCB The main modules of the Apollo DAC are made on the multi-layer PCBs. All signal lines are precisely evaluated and designed with the rules of high frequency PCB design, and clock signals are made via microstrip shielded lines with exactingly controlled impedance. The PCBs are made from a material with controlled dielectric constant, utilizing high thickness copper conductors (35 and 55 um) with diffused gold solder points and covered with a special anti-static surface mask. All PCBs are made in Russia because of their superior quality in comparison with similarly priced and specified Swiss, German and US made PCBs. Enclosure The enclosure of the Apollo DAC was specially designed to provide an excellent vibration absorption while being extremely robust and acting as a very good electrical shield. As with many devices designed with a view to achieving the highest possible performance, we feel that it also achieves an appealing design aesthetic. The inclined plane latches at the edges of the case panels make the case structure very rugged and ensure correct acoustic wave reflection at the cross-edges. All panels are made of aluminum alloy designed to offer high mechanical decrement and low wave speed. The panels are milled at a precision milling station and exposed to an ultrasonic inner-defect control process after milling. The configuration of the enclosure panels and the points of the feet mounting were designed taking into account the mathematical model of sonic wave interference. -------------------------------------------------------------------------------------------------------------------------------------- The effect of this cumulative and exacting attention to detail is a product that we feel redefines what can be expected from digital audio. The Apollo is the physical manifestation of Tchernov’s compromise free approach to design and manufacture and we invite you to discover the difference.
DAC Apollo Specifications
Audio outputs (High current class A discrete buffers)
2-channel balanced analog audio output (XLR). 2-channel single phase (unbalanced) analog audio output (RCA).
Audio inputs 2-channel balanced AES/EBU ( XLR, 110Ω).44.1 kHz to 192 kHz sampling and up to 24-bit precision. 2-channel coax SPDIF input (75Ω, IEC 60958 ). 44.1 kHz to 192 kHz sampling and up to 24-bit precision. 2-channel digital optical input (Toslink type) 44.1 kHz to 96 kHz sampling and up to 24-bit precision. One USB 2.0 ( B type) input up to 384 kHz sampling and up to 32-bit precision.