Before extolling the processor performance, we must mention its excellent sound quality as a piece of audio equipment. The AZ-1 D/A converter with digital processor, a symbol of Bewith’s electronic technology, offers unprecedented adjustability that enables a cutoff slope of 300dB/octave. Developed with the intention of reaching the summit of sound quality for a car D/A converter, its rich sound quality exhibits no tone color fading over the passage of time and has the supreme ability to express sound in your own car.
Digital Processor DA Converter
Mirror Station® AZ-1
End of sales
|DSP/Pre Amplifier||Equalizer||Select 15 points from 59 points / Adjustable at -0.1dB steps (-12dB maximum)|
|Left / Right Independent||Cut off slope||-12 – -300dB/oct. Level adjustment at -0.1dB steps|
|Cut off Frequency||Select from 54 points|
|Time Alignment||Adjustable at 0.77cm (0.02ms) steps between 0.00cm (0.00ms) – 499.73cm (14.70ms)|
|Frequency responce||10Hz – 20kHz (±0.5dB)|
|Maximum output voltage / Inpedance||4.72Vrms/10KΩ|
|Total harmonic distortion||0.0015% (1kHz, 20kHz, L.P.F)|
|Input / Output Terminals||Audio Input||3 digital inputs (2 opticals, 1 coaxial)
2 analog Inputs (RCA line, Stereo minijack plug)
|Audio Output||3way 6ch RCA Line outputs (TW, MW, SW)|
|Video input||1 composite video input|
|Video output||1 composite video output|
|Signal to noise ratio||115dB (IHF-A network)|
|Maximum current consumption||2.4A (14.4V_DC)|
|Power source||DC14.4V (11.0V – 16.0V allowable)|
|Dark current||< 5mA (ACC OFF or POWER OFF)|
|Accessory||Remote Control / Remote Eye|
All component parts including the specially designed film condenser were scrupulously selected. At the highest peak of car-installed equipment, the 192kHz/24-bit, high performance DAC device from Cirrus Logic has an exclusive tweeter, midwoofer, and subwoofer for a total of three boards. A TI op-amp IC board specially designed for acoustics, which loads its output on the A-110S power amplifier, is installed on each channel (six boards in total) in an analog buffer circuit at the low-pass filter or after. In addition, evaluation tests extending for over six months were carried out in studios and in vehicles. Going beyond specs and data, we have advanced into the area of “personal preferences” by capturing the expressive power of music at a different dimension, reproduced with a sense of depth through the recording time ambience and placement of each part.
During our pursuit of sound quality to the extreme limit in the D/A converter unit, we discovered the impact of fine jitter generated within the DSP on sound quality. In the AZ-1, jitter within the DSP is eliminated by upsampling the audio data input from the DSP to the D/A converter at up to 192kHz and running the device asynchronously. The blind spots of the digital multisystem are resolved by the TI sampling rate converters in the dedicated tweeter, midwoofer, and woofer. Sound quality degradation is kept to a minimum through upsampling at frequencies up to 192kHz by using a highest echelon Cirrus Logic device on the external analog input signals.
In this design, the printed wire pattern of the analog audio circuit from the D/A converter output to the audio output terminal has completely isometric L/R length and the circuits for the tweeter, midwoofer, and subwoofer regions have completely identical patterns. The board lowers impedance to the extreme limit through a four-layer structure with an internal layer foil thickness of 70μm and a surface layer thickness of 35μm, and more specifically by use of 70μm wiring for the audio circuits and audio power circuits and by making all corners R-shaped. Through an exquisite design clearly delineated from mixed analog/digital systems, we have achieved high purity sound quality and an overwhelming sense of a high signal-to-noise ratio.
The audio system is equipped with high-efficiency, low energy consumption power circuits that maintain a complete separation between the audio and the video/control circuits. In particular, the audio system power has a fully discrete layout equipped with an independent, stable power supply employing audio regulator circuit technology, and circuit impedance is lowered to the extreme by inclusion of special acoustic parts. In addition to the focus on high efficiency and low current consumption, we have kept radiation and heat, which threaten sound quality, to a minimum.
Adopting an FIR filter in which phase rotation from filtering does not generally occur, the AZ-1 is equipped with an L/R, independent, 3-way digital processor that achieves ideal signal processing with no impact on sound quality and orientation even during crossover network and equalizer use. The equalizer has a cutoff slope of –12 to –300dB/oct. (–0.1dB per step), a time alignment of 0.77cm (0.02ms) steps, and a bit lossless negative control with 59-point selection (–0.1dB per step). Based on the outstanding tuning ability that typifies the equalizer and tuning operation* that employs Bewith’s unique SIEG® in-vehicle acoustic measurement system, the AZ-1 boasts sound tuning previously not possible at a precision that approaches its theoretical value.
* Installation and tuning of this equipment is handled by exclusive sales outlets for Bewith products (SIEG® equipment vendors). Sound tuning requires special equipment for measuring in-vehicle acoustics (SIEG®) and special software, and cannot be done by the customer. Also, labor and other costs for installation and tuning are not included in the indicated product price.
L/R are completely isometric in 4-layer boards with a substrate thickness of 70μ
High efficiency, low current consumption power circuits
L/R independent 3-way digital processor
Sample tuning window using special software.