MOSFET Output Stage
The bi-polar transistors used in the 200 are run in Class-A. This avoids the crossover notch distortion and the resulting odd order harmonics present, to some degree, with this sort of operation. The output devices used in the output stage are MOSFETs. High quiescent current circuitry runs the 200 in the equivalent of Class-A up to 10 Watts. Beyond this point the output class is technically Class-AB, but with a major difference, the combination of MOSFET characteristics and their application in this circuitry result in crossover distortion so minimal that it is virtually non existent.
Perreaux was the first company in the world to utilise MOSFETs for high powered amplifier applications. We are very experienced in the use of these devices (25+ years), we understand them well and feel that the devices have continued to improve in recent years. The 200 output stage takes full advantage of the unique qualities of MOSFET devices and in many ways they are superior to bi-polar transistors. A major advantage is their tendency to draw less current over a large section of the power bandwidth as their temperature rises (Negative Temperature Co-efficient), hence, self stabilising thermally, whereas bi-polar transistors draw more current as their temperature rises (Positive Temperature Coefficient) and protection circuits become mandatory to prevent thermal runaway and eventual self destruction. MOSFETs have the ability to swing fully across the amplifier’s internal DC voltage and are therefore true "rail-to-rail" devices.
Our products have withstood the test of time. The devices are incredibly robust and we experience very few MOSFET failures, even on older products. The use of MOSFETs also assists us in our quest to keep the signal path as clean as possible, by largely negating the use of additional thermal stability circuitry as required in BJT designs.
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Superior Power Supply Design
To negate audible hum, we use only high quality, custom designed, toroidally wound, epoxy cored transformers. The 200 has 40,000uF of smoothing capacitance in the power supply. The 200 is capable of delivering more than 500W of impulse power into a 4Ω load. That is why there is always enough energy to supply loudspeakers of low efficiency and also why the 200 accommodates any musical transients with ease. The output stage features no fewer than 6 MOSFETs per channel (12 in total) and uses highly refined voltage and current drive circuitry. The massive power supply, working in close combination with the parallel MOSFET output stage makes the 200 a stellar performer.
Noiseless Earthing Techniques
We pay particular attention to designing the product to ensure maximum separation between internal signal and power earths only meeting at a central starred point.
High Quality PCBs and Components
Quality fiberglass PCBs, featuring heavy copper tracks and high-grade components, are used throughout the 200.
Bi-Wiring Made Easy
2 pairs of binding posts per channel make bi-wiring speakers as simple as "A-B-C".
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