The QMP Mono Power Amplifier is a by-product of the earlier 909 Mono with enhancements distinctly noticeable in amplifier construction and circuitry, and is capable of producing an accurately balanced XLR. Moreover, the new Elite QMP now incorporates a ‘current dumping’ feature allowing for a cleaner, more versatile performance. The QMP Amplifier is a bridged mono bloc version of the QUAD QSP Stereo Power Amplifier and can be used used in conjunction with it. Current Dumping - The QMP Amplifier incorporates QUAD's patented current dumping technology developed by QUAD's founder Peter Walker, and is one of the finest audio amplifiers available. One of the few truly innovative amplifier topologies, it is essentially a combination of two amplifiers to give the best of both in each channel.
The current dumping circuit like the Quad QMP Amplifier consists of a very high quality class A low-power amp which provides the details of the signal, while a high-power current dumping section provides the grip to keep the speakers under control. These two amplifier circuits are combined with a precision network to perfectly impose the finesse of the class A output onto the power of the current dumper. This technology eliminates the problems of crossover distortion, quiescent current adjustment, thermal tracking and transistor matching. There are no internal adjustments or alignments and the choice of power transistor types is less restrictive.
The history of Quad is one of technical achievement in the field of sound reproduction. It is a story that began with the Quad 1 amplifier, which brought the benefits of 15 years knowledge and experience in professional audio and industrial products to the task of making the most accurate domestic audio amplifier of its age.A few years later, in 1953, the product which set the standard for amplifiers was the Quad II Power Amplifier, the time of Queen Elizabeth’s Coronation and the year in which Mount Everest was finally conquered. This amplifier pioneered the principle of cathode coupling through the output transformer to reduce harmonic distortion to almost negligible levels. Such was its clear superiority that this model remained in production for 18 years. Three years later, in 1956, Quad demonstrated the first true full-range electrostatic loudspeaker. This remarkable product (known later as the ESL 57) used a virtually mass-less plastic film as a moving diaphragm between two charged plates. Compared with moving coil loudspeakers, the ESL 57 was free of unwanted colourations and distortions. This landmark product remained in production, virtually unchanged, for 28 years.
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