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English
Appendix B: Specifications
Specifications for Bose
®
Model 21
50 Commercial Power
Amplifier
Power Output
Continuous average output power, both channels driven:
150W per channel into 4Ω at 1kHz with 0.5% or less THD
150W per channel into 8Ω at 1kHz with 0.5% or less THD
150W per channel at 100V into a 67Ω load at 1kHz with 0.5% or less THD
150W per channel at 70V into a 33Ω load at 1kHz with 0.5% or less THD
Bridged mono operation:
300W at 8Ω with 0.5% or less THD
300W at 16Ω with 0.5% or less THD
300W at 100V into a 33Ω load at 1kHz with 0.5% or less THD
300W at 70V into a 16Ω load at 1kHz with 0.5% or less THD
Power consumption:
60W or less at idle, no input, maximum gain
125W with musical program at
1
⁄
8
rated power
250W with musical program at
1
⁄
3
rated power
Power requirements:
485W @ 4Ω with a sinewave test tone, rated continuous power at maximum gain
500W @ 8Ω with a sinewave test tone, rated continuous power at maximum gain
525W @ 70V with a sinewave test tone, rated continuous power at maximum gain
525W @ 100V with a sinewave test tone, rated continuous power at maximum gain
Net weight Shipping weight
35 lbs. ( 15.9 kg) 38 lbs. ( 17.2 kg)
Output configurations
Audio output transformer taps per channel: 100V, 70V, 50V, 35V, 25V, 8Ω, 4Ω
Dynamic headroom
1.2 dB
Full power bandwidth
30Hz to 20kHz @ 0.5% THD
Frequency response
30Hz to 20kHz (-3dB)
Channel separation
>80dB @ 1kHz
Input impedance
50kΩ balanced; 25kΩ unbalanced
Sensitivity
0.775V for rated power @ 1kHz
Maximum input
+ 20dBu (7.75 V)