Crown Com-Tech CT-1610 Service Manual page 12

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In an effort to provide you with as much information as possible about the high power-producing capabilities of your amplifier, we have
created the following power matrices.
Minimum Guaranteed Power Specifications
Crown's minimum power specifications represent the absolute smallest amount of output power you can expect from your amplifier when
it is driven to full output under the given conditions. Some spaces in each matrix may be left blank because the same guarantee is not
provided for those conditions—however, your amplifier will perform well under all conditions listed in each matrix.
When measuring power, 0.1% THD appears to be the industry standard for distortion. Two of the maximum average power specifications
shown in each minimum power matrix are measured at 0.1% THD so you can easily compare Crown specifications to those of other
manufacturers. But this high level of distortion actually allows for some clipping which is undesirable. Because of this, a maximum average
power specification at 0.05% THD is included in each minimum power matrix which represents non-clipped conditions. Although most
manufacturers do not give you power specifications at 0.05% THD, we encourage them to provide these specifications so you will have a
more realistic representation of the way amplifiers should be used in the real world—without a clipped output signal.
Many manufacturers publish power specs with a tolerance of ±1 dB or worse. This means their amplifier can deviate more than 20% in
output! A 100 watt amplifier would meet their specification if it only produced 79.4 watts. Other manufacturers qualify their specs by saying
Com-Tech 810 –
Dual/Mono At 0.1% THD
Mode
4
Dual
8
(both channels
driven)
12.5 (70V)
8
Bridge-Mono
16
(balanced output)
25 (140V)
2
Parallel-Mono
4
6.25 (70V)
4
Dual
8
(both channels
driven)
12.5 (70V)
8
Bridge-Mono
16
(balanced output)
25 (140V)
2
Parallel-Mono 4
6.25 (70V)
4
Dual
8
(both channels
driven)
12.5 (70V)
8
Bridge-Mono
16
(balanced output)
25 (140V)
2
Parallel-Mono 4
6.25 (70V)
Figure 2.6 Com-Tech 810 Minimum Power Matrix
2-6
Com-Tech 810 and 1610 Amplifier Service Manual
Crown specifications are guaranteed for three years.
Minimum Guaranteed Power (Watts)
Maximum Average
At 0.1% THD At 0.05% THD
(See note 1) (See note 2) (See note 3)
1 kHz 20Hz-20kHz 1 kHz
490 460 480
305 295 300
460 455 455
975 935 965
610 600 605
920 905 905
965 950
610 600
915 905
460 440 460
300 290 295
425 415 420
925 885 915
600 580 595
855 825 850
925 920
600 595
855 845
485 470 485
310 305 310
440 430 435
965 920 955
620 605 615
885 855 875
940 930
615 610
875 870
they are "typical, " "subject to manufacturing toler-
ances, " "single channel driven" or that they are
specified with "fuses bypassed. " Each of these
FTC Continuous Average
statements effectively removes any performance
At 0.1% THD
guarantee. In fact, some manufacturers use these
(See note 4)
tactics to generate large power numbers, and
they don't even print a disclaimer. We take a dif-
1 kHz 20Hz-20kHz
ferent approach at Crown—our amplifiers are
470 455
guaranteed to meet or exceed their specifications
300 290
for three years. Further, because our published
specs are set below our "in-house" measure-
450 445
ments, you can expect every Crown amplifier to
950 905
meet or exceed its published minimum power
605 600
specs. We believe you should get what you pay
for.
905 880
950
Minimum Power Notes:
All minimum power specifications are based on
605
0.5% regulated AC mains with THD of less than
910
1.0% and an ambient room temperature of 70° F
(21° C). Standard EIA power (RS-490) is not shown
445 425
here because it is identical to FTC Continuous Av-
295 290
erage Power.
410 400
1. A 1 kHz sine wave is presented to the amplifier
and the output monitored for nonlinear distor-
890 840
tion. The level is increased until THD reaches
595 575
0.1%. At this point, average power per chan-
830 800
nel is reported.
895
2. A sine wave is presented to the amplifier over
the range from 20 Hz to 20 kHz and the output
595
monitored for nonlinear distortion. The level at
830
each frequency is increased until THD reaches
0.1%. At this point, average power per chan-
465 450
nel is reported.
310 300
3. A 1 kHz sine wave is presented to the amplifier
425 420
and the output monitored for nonlinear distor-
tion. The level is increased until THD reaches
930 875
0.05%. At this point, average power per chan-
615 600
nel is reported.
865 840
4. Continuous power in the context of Federal
Trade Commission testing is understood to be
920
a minimum of five minutes of operation. Har-
600
monic distortion is measured as the RMS sum
855
total and given as a percentage of the funda-
mental output voltage. This applies for all watt-
ages greater than 0.25 watts.
Rev. 0