Accuphase was founded in 1972 and conquered the Hi-Fi world with a high-end amplifier. Their A-200 is another example of a sophisticated technology focused on delivering sound without compromise.
Article continues below
The short description would be: pure Class A operation delivers 100 watts into 8 ohms; two totally identical power amplifier units driven in parallel; 20-parallel push-pull arrangement of MOS-FETs in output stage delivers linear high power progression to ultra-low 1-ohm impedance. Prety impresssive, but there's more.
Class-A Monophonic Power Amplifier A-200 features two completely separate power amplifier units, each with its own dedicated heat sink, driven in parallel. That completely parallel configuration allows a significant increase in output current and results in a power amplifier with extremely low output impedance. With the choice of the finest parts and advanced circuits, A-200 has an amazing damping factor greater than 1,000.
A pure class A amplifier consumes a considerable amount of power and produces heat all the time, which means that the circuitry has to be designed to ensure problem-free operation in any environment. The power MOS-FETs used in the A-200 are renowned for their excellent high-frequency characteristics and high thermal stability. This allows finely honed control to maintain the temperature balance between two power amplifier units, achieving stable operation even when the load and operating conditions change dramatically.
Another characteristic of the A-200 is its great S/N ratio. By using only discrete electronic components instead of integrated circuits and fine-tuning the gain complement with the following stage, simply amazing S/N ratings were achieved: 126 dB at the maximum gain setting and 132 dB with gain set to -12 dB.
Two sets of oversize speaker terminals accept Y lugs and allow bi-wiring, and fully balanced input stage shuts out external noise interference. Mode selector allows use of two A-200 units for bi-amping or bridged operation. Bridging enables upgrade to monophonic amplifier with even higher power, delivering 1,600 watts into 2 ohms (music signal), 800 watts into 4 ohms, or 400 watts into 8 ohms. ■
