SPECIFICATIONS ISA 280 ISA 450 ISA 750
OUTPUT POWER

in watts

FTC:

8 ohms per channel (20-20k Hz., 0.1% THD) 185 260 450
4 ohms per channel (20-20k Hz., 0.1% THD) 280 425 650

EIA:

16 ohms (1 kHz., 0.1% THD, 1 channel driven) 100 140 250
8 ohms (1 kHz, 0.1% THD, 1 channel driven) 200 280 475
4 ohms (1 kHz, 0.1% THD, 1 channel driven) 300 500 750
2 ohms (1 kHz, 1% THD, both channels driven) 430 700 1200

Bridged Mono:

16 ohms, 20–20k Hz, 0.1% THD 370 520 900
8 ohms (1 kHz, 0.1% THD) 600 900 1500
4 ohms (1 kHz, 1% THD) 830 1400 2400
DYNAMIC HEADROOM (all models) 2 dB at 4 ohms
DISTORTION (SMPTE-IM, all models) LESS THAN 0.01% LESS THAN 0.01% LESS THAN 0.01%
FREQUENCY RESPONSE (all models) 20 Hz to 20 kHz, +0, -1 dB
(at 10 dB below rated output power) -3 dB points: 5 Hz and 50 kHz
DAMPING FACTOR (all models) Greater than >200 for 8 ohm load
SIGNAL to NOISE (unweighted, 20-20k Hz.) -100 dB -100 dB -100 dB
VOLTAGE GAIN (gain control set to 0 dB) 30.5 dB (33.4.X) 33.0 dB (44.7 X) 35.0 dB (56.2 X)
INPUT SENSITIVITY for rated power into 8 ohms +3.43 dBu (1.15 Vrms) +2.81 dBu (1.07 Vrms) +2.81 dBu (1.07 Vrms)
INPUT CLIPPING, Vrms (all models) +22 dBu
INPUT IMPEDANCE (all models) 10k ohms unbalanced , 20k ohms balanced
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