D-02 STEREO DAC
A new design implementations from Esoteric
Esoteric’s P-02 SACD/CD transport and D-02 system DAC, aim at the highest level of audio performance, which is only possible using separate audio components, based on the company’s basic product design concepts. The P-02 and D-02 have incorporated a number of new technologies such as “ES-LINK3” and “35-bit D/A processing.” The P-02 and D-02 are new design implementations from Esoteric, which are totally dedicated to evolving the critical listening experience for music enthusiasts.
Dual monaural D/A converter configured with eight circuits per channel and “35-bit D/A processing” capability.
The D/A converter ICs of the D-02 incorporate top-end 32-bit AKM devices AK4399 chipsets,” manufactured by ASAHI KASEI Microdevices Corporation. Eight circuits per channel are provided to achieve phenomenal linearity and low noise. In addition to direct processing of DSD signals, the D-02 has newly adopted a “35-bit D/A processing” algorithm that converts PCM signals to analog signals, at a high resolution of 35 bits, so the D-02 achieves an improved level of delicate sound quality with ultra high resolution.
The D/A converter circuits are mounted on separate analog audio boards for each of the left and right channels. All components, including the power circuits and power transformers, are separated for right and left channels to implement a fully dual monaural configuration. This identical layout per channel, achieves ideal power supply performance and excellent channel separation, enabling high-quality playback with a rich localization and sonic depth.
Fully discrete Class A buffer circuit
The D-02 is configured with a fully discrete Class A buffer amplifier with four circuits per channel, using twice the amount of high-grade components used in the K series all-in-one players. This Class A buffer amplifier is used for the analog audio output circuits at the final stage. A “double-parallel full-balance output,” that combines two buffer amplifier circuits for each channel of the hot/cold signal lines is used for the XLR audio outputs. Also, a “quadruple-parallel unbalanced output,” is used for RCA audio outputs.
The D-02 offers an exceedingly high drive capability and slew rate by means of a low-distortion and high linearity Class A buffer amplifier configuration and a high-voltage toroidal core power supply unit of +/-22V, (which is provided independently for each channel). As a result, the D-02 provides stress-free playback for various signals, from very low-level signals to demand for high-power outputs.
Abundant use of high-grade components in design
Esoteric has made maximum use of high-grade components for the internal construction of the P-02 and D-02. A total of eight independent Esoteric toroidal core power supply units are installed in the combined system to supply clean and stable power to each circuit. The inside of the chassis has our double-deck structure that is partitioned into 5 sections. Each circuit block is assembled in a dedicated compartment and placed three-dimensionally in order to minimize interference between circuits. A 3D optimized chassis construction also has been adopted to establish the shortest signal paths. The exterior is constructed using thick aluminum material whereas the bottom chassis is made of 5mm-thick steel. The bottom chassis is supported at four points with Esoteric-original pinpoint feet (patent No. 4075477). This four-point system effectively suppresses vibration, reduces resonance and assures extremely high rigidity.
New ES-LINK3 that enables broadband transmission
The D-02 supports for Esoteric’s original transmission format “ES-LINK3” and can perform a maximum 192kHz/48bit broadband PCM digital transmission on the D-02 using two XLR cables. The D-02 also supports for “Dual AES 8Fs” standard (maximum 24-bit/352.8kHz). Therefore the D-02 can perform conventional Direct Stream Digital (DSD) transmission and direct DSD-to-analog conversion processing for Super Audio CD (SACD) playback.
New dimensional isolated clock technology
The quality of music signals is impaired by jitter which is caused by the distortion of waveforms between the reference clock and signal data. The clock circuit, which supplies highly accurate reference clock signals to a digital circuit, is an extremely important component that can be considered to be the core unit for a digital player. The P-02 and D-02 adopt an isolated clock technology that completely isolates the clock circuit from other circuit blocks. The clock module assembled in both the P-02 and D-02, has been developed with an ingenious design to achieve the same quality as an external master clock generator available as a single unit. The clock module is equipped with a dedicated toroidal core power supply transformer and a power supply stabilizing circuit. The ground of the clock module is also isolated from other circuits. As a result, this module can supply pure clock signals to the system by completely minimizing the occurrence of random jitter that results from power voltage or ground voltage fluctuations.
Esoteric’s clock module adopts a Voltage Controlled Crystal Oscillator (VCXO) assembled with a large crystal element that is carefully selected from the aspect of sound quality. The P-02 transport and D-02 D/A converter are equipped with two VCXOs each in accordance with the frequencies to be processed. This VCXO system has demonstrated a high accuracy of +/-0.5ppm at the factory prior to shipment. Additional special care for sound quality is given to the connection between the built-in clock module and DAC module of D-02: they are hard-wired using coaxial cable. This cable uses a gold-plated SMA connector developed for high-frequency transmission, and keeps transmission losses of the audio clock to an absolute minimum, which is critical for improving sound quality.
Direct master clock LINK without PLL
The WORD sync function, which is one of the core technologies from Esoteric, synchronizes playback with the transport and D/A converter using an external WORD clock and effectively reduces jitter. The P-02 and D-02 have introduced a completely new system for WORD sync. This new system is called the “Direct master clock LINK without Phase-Locked Loop (PLL)” and it directly supplies the master clock to the P-02.
This master clock is a digital audio output reference clock (22.5792MHz) generated within the high-accuracy clock module of the D-02. The system also uses this master clock as the clock of the digital output circuit without passing through the PLL circuit in the P-02. Since this system does not pass through unnecessary or complicated circuits, it enables pure and direct clock processing and contributes to achieving a clear and accurate sound image localization and ultra clear sound quality.
Support for 10MHz master clock input and other wide-ranging clock connection options
The P-02 and D-02 can be connected to a conventional external WORD clock (44.1kHz, 88.2kHz, and 176.4kHz) in order to use a WORD sync function to synchronize playback. They also can be connected to a high-precision rubidium master clock generator such as the G-0Rb rubidium master clock. Furthermore, both the P-02 and D-02 are equipped with a 10MHz master clock input jack for connecting a 10MHz-output external clock system. In other words, you can connect the units to a wide variety of optional external clock generators for upgrading incrementally to a higher quality Esoteric sound system.
Wide-ranging D/D conversion functions for handling many source types
The D-02 is provided with wide variety of D/D conversion modes for the PCM format, including x2, x4, and x8 up-conversion, and PCM-to-DSD conversion, as well as a conversion mode from the original sampling frequency.
Four types of digital filters and digital filter OFF mode
The D-02 is equipped with four types of digital filters for PCM signal processing. Two types of short-delay digital filters are provided in addition to two types of Finite Impulse Response (FIR) digital filters. These short-delay digital filters eliminate the pre-echo effect in the impulse waveform to reproduce a more natural audio signal without any delay. A digital filter OFF mode is also available.
Five digital input systems for high sampling rate support
The D-02 is equipped with wide-ranging digital inputs of five types for eight channels (XLR x2, i.LINK 4p/6p x1, USB x1, coaxial x2, and optical x1). The D-02 can be used for high-sampling-rate sources of up to 24-bit/192kHz. XLR x2 provides support for high-sampling-rate/high-bit inputs of 48-bit/192kHz (ES-LINK3) and 24-bit/384kHz (Dual AES 8Fs).
USB input with asynchronous transmission and 24-bit/192kHz source support
The D-02 uses Esoteric-original PC driver software to provide support for fully asynchronous transmission and input of high-sampling-rate sources of 24-bit/192kHz. The D-02 is also equipped with a USB isolator that prevents interference from a personal computer and other external devices in order to achieve high-grade playback of music files including studio master-quality source files.
A 32-bit high-precision digital attenuator function
This function enables volume control with no degradation of sound quality caused by dropouts by taking the advantage of a phenomenal 35-bit range. The D-02 can therefore be directly connected to a power amplifier.
The D-02 can switch the output voltage of XLR audio outputs in accordance with the input sensitivity of the amplifier (0dB/+6dB). Either Hot 2 or Hot 3 can be assigned for XLR audio outputs.