Ultra-low-noise design with unprecedented S/N ratio of 127 dB brings out a stunning wealth of detail. Semiconductor MOS-FET switches enable output circuitry without any mechanical contacts. Two pure class A power units arranged right and left are driven in parallel to deliver 100 watts into 8 ohms with impeccable quality. A damping factor in excess of 1,000 means that speaker control is nothing less than perfect. The massive A-250 represents a new pinnacle in power amplifier history. Encounter music like never before.
- 20-parallel push-pull arrangement of power MOS-FETs delivers linear power progression: 800 watts (music signal) into 1 ohm, 400 watts into 2 ohms, 200 watts into 4 ohms, or 100 watts into 8 ohms.
- Strong power supply with massive high-efficiency toroidal transformer and two large 100,000 µF filtering capacitors.
- Printed circuit boards in power amplifier assembly made from glass cloth fluorocarbon resin with low dielectric constant and minimum loss.
- 4-stage gain selector (MAX, –3 dB, –6 dB, –12 dB) also minimizes residual noise.
- Two sets of oversize speaker terminals accept also spade lugs and banana plugs and allow bi-wiring connection.
- Semiconductor (MOS-FET) switches used for protection circuitry prevent contact problems and ensure long-term reliability. Eliminating mechanical contacts from the signal path also further enhances sound quality.
- Fully balanced input stage shuts out external noise interference.
- OPERATION selector allows use of two A-250 units for bi-amping or bridged operation. Bridging allows 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.
- Output level indication switchable between 5-digit numeric readout and 40-point LED bar graph with further improved readability. Hold time selector button also provided.
- Digital power meter showing true power values, based on output current detected by a Hall element.
- 27% higher Damping factor than previous model (A-200)
- Major parts in power supply and signal path are gold-plated.
Continuous Average Output Power (20 - 20,000 Hz)
Normal mode 800 watts into 1 ohm ＊1
400 watts into 2 ohms
200 watts into 4 ohms
100 watts into 8 ohms ＊2
Bridged mode (2 units) 1,600 watts into 2 ohms ＊1
800 watts into 4 ohms
400 watts into 8 ohms
Total Harmonic Distortion 0.05% with a 2-ohm load
0.03% with a 4 to 16-ohm load
Intermodulation Distortion 0.01%
Frequency Response At rated continuous average output: 20 - 20,000Hz ＋0 －0.2 dB
At 1 watt output: 0.5 - 160,000Hz ＋0 －3.0 dB
Gain 28.0 dB (GAIN selector in MAX position)
Gain Selection MAX, –3 dB, –6 dB, –12 dB
Output Load Impedance Continuous output: 2 to 16 ohms
With music signal: 1 to 16 ohms
Damping Factor 1,000 Gauranteed, Max 1400
Input Sensitivity 1.13 V for rated continuous average output
(with 8-ohm load) 0.11 V for 1 watt output
Input Impedance Balanced: 40 kilohms
Line: 20 kilohms
Signal-to-Noise Ratio 127 dB (GAIN selector in MAX position)
(A-weighted, with input 133 dB (GAIN selector in –12 dB position)
shorted) At rated continuous average output
Output Level Meter Digital power meter
5-digit indication showing true power (W)
Range selection AUTO / 10 W / 100 W / 1,000 W
Bar graph meter
Represents output voltage values (dB) using 40 points
Peak hold time
1 second / ∞ (infinite) selectable
＊Display off switch provided
Power Requirements 120/220/230 V AC, 50/60 Hz
Power Consumption 300 watts idle
430 watts in accordance with IEC 60065
Maximum Dimensions Width 465 mm
Height 238 mm
Depth 514 mm
Mass 46.0 kg net
55.0 kg in shipping carton