YAMAHA MX-2000 (1988)

 

A cutting-edge power amplifier that achieves ideal Class A operation, with a focus on low impedance and drivability. Class A operation over the entire load and power range. HCA (Hyperbolic Transform Amplification) circuit. Conventional Class A amplifiers have struggled to achieve high power, especially when driving low impedance, but Yamaha's unique HCA circuit has been incorporated into this amplifier. This circuit achieves Class A operation over the entire load and power range. Furthermore, because the HCA circuit operates as a pure converter with no feedback loop or gain, transient response is always excellent. High-power 4-parallel push-pull amplifier with MOS FET power buffer. The output element of the power buffer stage employs a power MOS FET, known as the most advanced audio output element available today. Because the power MOS FET is a voltage-controlled element with high input impedance, it places less strain on the driver stage and allows for circuit simplification, among other advantages. The MX-2000 employs eight of these power MOS FETs per channel in a quad-parallel push-pull configuration, achieving a Class A rated output of 150W + 150W (6 ohm). Combined with the inclusion of an HCA circuit, this achieves a high Class A dynamic power output of 600W + 600W (1 ohm). A dual FET input voltage amplifier that achieves wide bandwidth and high slew rate. The first stage voltage amplifier, which amplifies the voltage, uses the most sophisticated dual differential input cascode boost circuit configuration. The AK4110 employs a strap circuit, which provides outstanding wideband characteristics and a high slew rate that is resistant to transient inputs. Furthermore, by positioning the voltage amplifier board close to the input terminals, it achieves low noise and a high S/N ratio. Relay and output coil distortion is also eliminated. Direct error correction amplifier. To ensure perfect matching with the connected speaker system and stable drive capability, only one speaker output is provided. Furthermore, by using only one output, overall distortion from input to output is thoroughly eliminated by incorporating a unique direct error correction amplifier. The unit achieves a low harmonic distortion of 0.003% (8 ohm 20-20,000Hz, 130W output), and a damping factor (a measure of speaker drive capability) of over 1000. High-quality design throughout. A new low-resonance chimney type heat sinker has been adopted. By adopting an oval shape that eliminates sharp angles in the heat dissipation section, the buzzing of the heat sinker due to resonance has been eliminated. In addition, luxurious gold-plated pass bars are embedded in the power stage board, promoting the transfer impedance of the power line and output line. Furthermore, audio-grade electrolytic capacitors are used throughout, ensuring a high-quality design. 420VA large massive power transformer. 20,000/F x 2 low-magnification electrolytic capacitors. The power supply section is designed to be just what is necessary and sufficient, with careful consideration given to power regulation and noise characteristics. It features a large, massive 420VA power transformer with an EI core and two 20,000µF electrolytic capacitors. Combined with the weight-optimized power transformer, this delivers a high-quality sound that simply cannot be achieved with large capacity. 

It is also equipped with a high-speed peak level meter that allows you to accurately read the output level. To ensure accurate readings of speaker output levels that change moment by moment in response to the music signal, the unit is equipped with independent left and right dB-scale logarithmic compression high-speed peak level meters. A protection-linked speaker switch that turns speaker output on and off while in power standby mode. ●Independent left and right detent-type input attenuators. ●Gold-plated brass pin jack terminals. ●Gold-plated brass speaker terminals compatible with extra-thick cables. Extra thick OFC power cord with polarity indicator. Specifications: ● Rated Output: 130W + 130 W (8 ohm 20-20,000Hz, up to 0.003%), 150W + 150W (6 ohm 20-20,000Hz, up to 0.003%), 180W + 180W (4 ohm 20-20,000Hz, distortion 0.01%) ● Frequency Response: 5-100,000 Hz ● Total Harmonic Distortion: 0.003% (8 ohm 20-20,000Hz - 130W) ● S/N Ratio: 125dB (IHF-A input shorted) ● Channel Separation: 95dB (1kHz, input shorted) ● Dimensions: 473 W x 170 H x 469 mm ● Weight: 28kg | Titanium color | Matching pre-amplifier CX-2000.