Special ideology

Analog-digital converter digital audio stream for converting digital audio data into an analog signal for subsequent amplification and sound reproduction. The device is implemented on the basis of the DAC type AK4490 chip structure "dual mono" in the signal part.

Chips DAC includes a differential circuit with a "double subtraction" output analog signals, dramatically reducing the level of conversion noise in the analog signal. Broadband High Linearity Analog subtracters with high common mode rejection ratio provides extremely low distortion of its own (below -120dB) and the suppression of the conversion noise to 100 dB at low frequencies and more than 65 ... 70dB at frequencies up to MHz units. In order to optimize the working conditions of subtractors, provides pre-filtering RFI DAC output chips.

The power supply and the formation of the reference voltage for each DAC chip is provided by 4 individual discrete stabilizers, ultra-low-noise, high temperature stability and long-term and near-zero output impedance over a wide frequency band. To eliminate the influence of the piezoelectric effect in the DAC chip reference voltage and supply chains are not used ceramic capacitors and lock chains performed specially designed capacitors are not subject to the piezoelectric effect.

Active analog reconstruction Bessel filter use only inverting OA operation, and their outputs buffered with discrete linear SE de- cascades in class A. All the outputs of the device are provided with special protective filters, RFI, excluding penetration of high-frequency noise in the signal chain OA. Power is provided from analog stages per channel low-noise bipolar linear regulators with high ripple rejection ratio and very low output impedance in the frequency range from DC to MHz.

Clocked process digital-to-analog conversion used switchable precision oscillators with extremely low phase noise at small offsets (corresponding to low-frequency jitter is less than 50 ... 70fs) and a complete quenching of generation in an inactive state. Generators are placed as close to the chips to reduce the DAC noise level is induced in the clock signal transmission line and emitted by it. For power generators uses its own high-precision discrete ultra low noise level stabilizer.

DAC control system is in the form of a static finite state machine without the use of microcontrollers, allowing to do without additional clock signals required in the case of microcontrollers, as well as to implement fully static LED indication, essentially do not interfere.

All electrical digital input devices are completely isolated from the main circuit. The interface module supports USB protocol Audio2.0 and AES3 protocol. When receiving signals over standard digital audio input using an original algorithm of jitter suppression by using a buffer memory with adjustable depending on the completion of the data writing speed and overflow protection / emptying, which guarantees the complete absence of jitter PLL master-clock recovery systems and eliminates the use of any kind of asynchronous re-samplers.

The device is powered from the power supply without the impulse of energy conversion. In it used specially designed and manufactured custom power transformers with low induction and very low stray fields, placed in a viscous medium without mechanical contact with the walls of the soft magnetic steel inside the screen. For maximum reduction of the mutual influence of analog, digital signal and digital service circuits used three separate transformer for each group supply chain. Rectifier power supply are based on Schottky diodes and are provided with transient suppression circuits when switching diode limiters and filter capacitor charging current pulse.

All DAC modules are mounted on a multilayer printed circuit boards, the topology of which designed to meet the requirements for high-frequency devices with a wide dynamic range and high-speed digital devices. The digital portion of the agreed signal transmission line, pie, "excavation" landfills and other measures to reduce interference and increase noise immunity circuits are widely used.

The handset element base of industrial (and higher) level, ensuring high reliability and stability of parameters over the entire service life. Installation of the analog signal and supply circuits BRC stranded conductors own Tchernov Cable production.

Mechanical constructive product is a specially developed sophisticated collapsible design milled from a special aluminum alloy panels with a large decrement mechanical oscillation system with self-locking precision components for assembly. Through this body has a minimum intrinsic mechanical resonances in the audio frequency range and has high strength at acceptable weight.