Lowveld Audio
Accuphase Chario WBT Isotek

Accuphase :: A-250 CLASS A  Power amplifier mono block 

A-200 mono block

Eminently capable pure Class A monophonic power amplifier with power MOS-FET technology. 
Realizing ideal speaker drive characteristics, the A-250 features two separate but completely identical power amplifier circuits driven in parallel, a damping factor of 1 000, and semiconductor (MOS-FET) switches instead of output relays to eliminate mechanical contact points. In the input stage, the ultra-low noise double instrumentation amplifier configuration enables fully balanced signal transmission, augmented by double MCS+ circuit and current feedback topology for minimal distortion and outstanding performance parameters. The result is astounding S/N ratio and ultra-refined sound quality. The massive power supply with a large high-efficiency toroidal transformer and plenty of filtering capacity supports an output stage with MOS-FETs in a 20-parallel push-pull configuration that realizes constant-voltage speaker drive. Printed circuit boards made from teflon with low dielectric constant and minimum loss, and gold-plating of major signal-carrying parts further enhance sonic purity. Bridged operation allows use of two A-250 units as a monophonic amplifier with even more power, capable of delivering 1 600 watts into 2 ohms.


  • Two totally identical power amplifier circuits driven in parallel
  • 20 parallel push-pull arrangement of MOS-FET devices in output stage
  • Input stage configured as double instrumentation amplifier
  • Double MCS+ circuit and current feedback topology in amplification stage
  • Support for bridged use of two A-250 units with even higher output power
  • Power supply with massive high-efficiency toroidal transformer and large filtering capacitors


  • Continuous average output power: 100 watts (8 ohms), 200 watts (4 ohms), 400 watts (2 ohms), 800 watts (1 ohm, music signal) / Bridged operation (2 units): 400 watts (8 ohms), 800 watts (4 ohms), 1 600 watts (2 ohms, music signal)
  • Frequency response: 0,5 Hz - 160 kHz +0, –3 dB
  • Intermodulation distortion: 0,01% or less
  • Damping factor: 1 000
  • S/N ratio: 126 dB (GAIN: MAX), 132 dB (GAIN:–12dB) (A weighted)
  • Rated input: 1,13 V


  • Two-way meter featuring digital indication of true power values and bar graph indication
  • Meter OFF/ALL/dB/W switching
  • Meter range selector: 10W/100W/1000W
  • Hold time selector button
  • Input selector
  • Gain selector
  • Mode selector 
  • Balanced inputs
  • Phase selector
  • Two sets of speaker outputs (simultaneous output)
  • Maximum dimensions: 465 (W) x 238 (H) x 514 (D) mm 
  • Mass: 46 kg