SHARP SM-SX200
* Made-to-order products
¥ 1,500,000 (released in December 2001)
Commentary
This is the world's first 1-bit digital amplifier that realizes 5.6 mhz switching 1-bit.
The 1-bit amplifier is developed from the operating principle of the class D method, which is the operation method of the amplifier.
In the Class D method, the audio signal is amplified by switching a high voltage and controlling the time in the ON state, and a PWM signal with a variable width in the time axis direction is used for the signal to control the switching.
In a 1-bit amplifier, a 1-bit signal is used as a control signal for switching control. By switching a constant voltage power supply with crystal precision timing using this control signal, power amplification with less degradation while maintaining the performance of a 1-bit signal is achieved.
Also, the switching signal that is finally voltage-converted is converted into an analog signal for driving a speaker with a low-pass filter.
The SM-SX200 achieves amplification performance exceeding the transmission range of Super Audio CD with high-speed 1-bit switching of 5.6 mhz.
We have also newly developed a 1-bit signal generation LSI that controls 5.6 MHz switching amplification, enabling expansion of the output amplitude level in stable operation, and realizing higher power with almost the same size as conventional products.
The power supply section consists of a switching power supply module. The power module DC/DC converter uses 0 voltage switching and 0 current switching to minimize radiation noise.
The 7th-order ⊿ Σ modulation 1-bit conversion LSI is fed back as a 1-bit digital signal for fluctuations in the power supply voltage that adversely affect sound quality, and ⊿ Σ dynamic feedback is adopted to correct the 1-bit control signal in real time, enabling stable amplification.
Due to the highly integrated control circuit, the volume density is 99W/inch.3It realizes high efficiency, small size and low heat generation.
Mutual interference is suppressed by independent configuration of power supply part and control part.
We use carefully selected circuit components such as gold-plated connectors and metal-coated resistors for internal wiring of 1-bit units.
Volume using gold plated multi-contact wire brush / low distortion carbon ink is adopted.
The input terminal uses a safety RCA pin jack that does not generate noise when connected while the power of the connected device is on.
An insulated double-pole terminal is used for the speaker terminal for biwiring.
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Model Rating
| Type | 1-bit amplifier |
| Rated Output (1 kHz) | 200W + 200W (4 Ω) 150W + 150W (8 Ω) |
| Frequency characteristic | 5 Hz to 100 kHz + 1-3 dB |
| Total harmonic distortion factor | 0.05% (at 1 kHz, 1W Output) |
| Dynamic range | 105dB |
| A/D Noise Shaping | 7th order ⊿ Σ modulation noise shaping |
| Input terminal | 1-bit digital input dedicated terminal : 1 system BNC coaxial digital input : 1 system RCA coaxial digital input : 1 system Square optical digital input : 1 system RCA analog input : 2 systems XLR analog balance input : 1 system Dedicated input terminal for 1-bit system : 1 line |
| Output terminal | Square optical digital output : 1 system RCA analog output : 1 system |
| Pwer | 100 VAC, 50Hz/60Hz |
| Rated power consumption | 195W (4 Ω at 200W + 200W output voltage setting) |
| Maximum external dimensions | Width 472x Height 89x Depth 480 mm |
| Weight | Approx. 19.0 kg |