Macro-Tech
®
602/1202/2402 Power Amplifiers
Page 30
Reference Manual
Crown specifications are guaranteed for three years.
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 specifica-
tions 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 spec 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 they are “typical,” “subject to manufacturing tolerances,” “single channel driven” or that they are
specified with “fuses bypassed.” Each of these statements effectively removes any performance guarantee. In fact, some
manufacturers use these tactics to generate large power numbers, and they don’t even print a disclaimer. We take a different
approach at Crown—our amplifiers are
guaranteed
to meet or exceed their specifications for three years. Further, because
our published specs are set below our “in-house” measurements, you can expect
every
Crown amplifier to
exceed
its pub-
lished minimum power specs. We believe you should get what you pay for.
Minimum Power Notes:
All minimum power specifications are based on
0.1% regulated AC mains and an ambient room
temperature of 70° F (21° C). International units
with multi-tap transformers are specified for the
worst-case transformer tap (normally 100 VAC,
50 Hz). The standard EIA power measurement
(RS-490) is not identified here because it is iden-
tical to the FTC Continuous Average Power speci-
fication.
1. A 1-kHz sine wave is presented to the ampli-
fier and the output monitored for nonlinear dis-
tortion. The level is increased until the THD
reaches 0.1%. At this level the average power
per channel is reported.
2. A sine wave is presented to the amplifier over
the range from 20 Hz to 20 kHz and the out-
put monitored for nonlinear distortion. The level
at each frequency is increased until the THD
reaches 0.1%. At this level the average power
per channel is reported.
3. A 1-kHz sine wave is presented to the ampli-
fier and the output monitored for nonlinear dis-
tortion. The level is increased until the THD
reaches 0.05%. At this level the average
power per channel is reported.
4. Continuous power in the context of Federal
Trade Commission testing is understood to be
a minimum of five minutes of operation. Har-
monic distortion is measured as the RMS sum
total and given as a percentage of the funda-
mental output voltage. This applies for all watt-
ages greater than 0.25 watts.
Fig. 6.1 Macro-Tech 602 Minimum Power Matrix
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