PMA-1520AE là mẫu ampli mới thay thế PMA-1510AE đã thành công nhiều năm qua. Ampli PMA-1520AE cải tiến kỹ thuật,thay thế nhiều linh kiện mới nhất của Denon, nhằm đưa ampli này lên một bậc về chất lượng âm thanh.
Rich sound from various music sources thanks to Advanced UHC-MOS single push-pull output circuit
The PMA-1520AE's remodeled Advanced UHC-MOS Single Push-Pull Circuit for instance or the twin transformers with leakage cancelling technology prove, that Denon always finds ways to advance their famed 2-channel products. The Precision Direct Mechanical Ground Construction thoroughly suppresses vibration thus minimizing adverse influences on the output signal. The power transformer, a major source of vibration, has been "float" mounted using a variety of vibration-resistant materials and a radiator stabilizer. It further owns separate power supplies for analogue and digital circuits. A chassis construction with independent blocks and the large highgrade volume potentiometer further suppress external noise and unwanted interferences between the parts. All relevant ingredients have been strictly selected to deliver the high sound quality for which Denon is renowned. The high-performance phono equalizer makes the PMA-1520AE the best choice also for vinyl lovers. Everything is protected by a thick aluminum front panel with the Denon logo engraved.
The amplifier features Advanced UHC (Ultra High Current)-MOS technology that utilises a minimum number of high-current amplifier elements to balance advanced speaker drive capabilities and improved sound quality. Advanced UHC-MOS is an ideal amplifier whose power supply performance is superior to that of bipolar transistors and incorporates the sound quality advantages of MOS-FETs. The Advanced UHC-MOS is provided in a single pushpull configuration that eliminates deviations in the amplification stage and balances high power with delicate musical details. This circuit masterfully reproduces the full sonic range, from the delicate musical nuances to the powerful climaxes of rich musical expression. A new Dual FET has been adopted for the input stage of the power amp. This feature-rich Dual FET suppresses the adverse influence of heat changes on sound, contributing to stable operation. Also, since a Cascade Bootstrap Circuit has been employed in the first stage of the differential amplifier circuit, superior amplification with negligible misalignment in frequency phase is now possible.
Direct Mechanical Ground Construction to minimise unwanted vibration
The PMA features a construction that thoroughly suppresses the adverse influences of vibration and electrical noise. Compared to previous models, the centre of gravity has been lower where the power amplifier board has been mounted closer to the bottom of the chassis, a construction that protects the circuitry from vibration. A twin monaural configuration with L/R symmetry has been adopted for the power amplifier block. And since circuits with different signal levels have been separated, they are thoroughly protected from mutual interference or noise. These design improvements contribute to a highly transparent, expressive sound.
Leakage-cancelling-mounted twin transformers
Two transformers have been connected in parallel to dramatically improve electrical and magnetic characteristics. The Leakage Cancelling (LC) mounting system, a method of cancelling mutual magnetic influences, has been used to minimise the leaking of magnetic flux, a source of noise inside the amp. The transformers were mounted with a plate between them and the chassis. Unlike conventional models, this plate is dual-layered. A combination of special resins and vibration-resistant materials has also been used to produce a floating effect that prevents adverse influences from affecting sound quality.
High-current, dynamic power supply, to support high speed and large current flow
The high-grade volume control, an element that significantly influences the quality of sound from an amplifier, is the same motordriven volume used in the high-class top model. Denon engineers carefully tested several types of volume controls before deciding that this was the one that best brought out the expressive power of sound in a class of its own.
Minimum signal paths, to protect signal purity
Low-noise Schottky barrier diodes, well known for its superior switching characteristics, have been used in the rectifier circuit. The Schottky barrier diode provides ample current capacity to accommodate ongoing successions of large bursts in sound while preserving its power and stability. Lower impedance has been achieved by doubling the normal thickness of copper foil used in the power supply circuitry, a design that adds stability to the current supply. The use of custom parts for the block capacitor, thoroughly tested for their contribution to high sound quality, further underscores Denon's uncompromising approach to audio technology and impeccable sound.
Signal paths have been made thoroughly simple and straight to ensure a pure playback sound. The minimization of signal paths prevents signal degradation between circuits. In the amplifier stage, minimum signal paths reduce noise entering the ground circuit, a fundamental component in signal amplification, and stabilized ground potential. When the operating foundation of the amplifier circuit is clear, the playback sound is also clear.
NEW AND UPGRADED FEATURES
Power amplifi er section
Input sensitivity / Impedance