Specifications
60
Australian
L A B R E P O R T
AD
61
SEE REVIEW ON PAGE 24
Marantz PM-KI-Pearl Integrated Amplifier
TesT ResuLTs
Marantz has a history of under-specifying
the power output of its amplifiers, so I wasn’t
at all surprised to see that on Newport Test
Labs’ test bench, the PM-KI-Pearl comfortably
delivered a minimum 110-watts per channel
into 8Ω (both channels driven) and, under
the same conditions, a minimum 160-watts
per channel into 4Ω and 200-watts per
channel into 2Ω. That is, all output levels
were well above specification. You can see
from the output levels in the accompanying
table—and the bar graphs published with the
main review—that in all cases the limiting
factor on 20Hz-20kHz power output was the
amplifier’s performance at high-frequencies
(in this case, at 20kHz) but in fact the power
output was remarkably constant irrespective
of the test frequency. Note particularly the
high power levels that are available right
down at 20Hz, under all test conditions—and
even into 2Ω loads. The Marantz’s ability
to deliver 267-watts at 20Hz into 2Ω, for
example, means a continuous current ability
of more than 11-amps.
The frequency responses again show
Marantz erring on the cautious side with its
specifications, with the company claiming a
response of 5Hz to 100kHz and Newport Test
Labs measuring the review PM-KI-Pearl with
a frequency response of 0.7Hz to 310kHz
–3dB! The 20Hz – 20kHz response was within
0.18dB, as you can see on Graph 5. Note,
however, the rising response at low frequen-
cies, which seems to be a quirk of the design,
in that the low-frequency response rose as
the frequency decreased, to eventually peak
at 15dB at 2Hz, before rolling off rapidly
to d.c. Graph 5 also shows the frequency
response into a typical loudspeaker load
with the tone controls in circuit, but at the
‘detent’ position. You can see the response
rolls off below 50Hz to around 12Hz (before
rising again to peak at 2Hz), but above 50Hz,
there is very little variation in the response,
indicating a low output impedance (it was
measured at 0.0399Ω), and therefore a high
damping factor. Despite the l.f. roll-off when
the tone controls are in circuit, the audio
band response is still an excellent 20Hz to
20kHz ±0.25dB.
The action of the tone control circuit was
unusual, in that it was more parametric than
Baxandall, with maximum bass boost and
cut of 10dB occurring at 50Hz and with a
particularly high Q, so that by 150Hz, there
was only around 3dB of boost and cut. This
means you’d be able to extract quite a bit
more bass from a small bookshelf speaker
without inducing any midrange colora-
tion—though you’d have to be careful not to
overpower the driver! The treble boost peaks
at 20kHz, again with a very high Q. The ef-
fect on the midrange is minor—less than 1dB,
which is excellent.
Channel separation was also excellent,
particularly at 1kHz, where Newport Test Labs
measured 91dB, but it held up well at 20Hz
(68dB) and at 20kHz (72dB). Channel balance
was 0.085dB at 1kHz, well below the level of
perception. Also below the level of perception
Test
Measured Result Units/Comment
Frequency Response @ 1 watt 0.8Hz–170kHz –1dB
Frequency Response @ 1 watt 0.7Hz–310kHz –3dB
Channel Separation 68dB/91dB/72dB (20Hz/1kHz/20kHz)
Channel Balance 0.085dB @ 1kHz
Interchannel Phase 0.03/0.11/0.07 deg (20Hz/1k/20k)
THD+N 0.006% / 0.004% 1 watt/rated o/p
S/N Ratio (unweighted/weighted) 84dB/90dB dB re 1 watt output
S/N Ratio (unweighted/weighted) 94dB/100dB dB re rated output
Input Sensitivity (CD input) 23.5mV/221mV (1 watt/rated o/p)
Output Impedance 0.0399Ω OC = 2.0715V
Damping Factor 200 @ 1kHz
Power Consumption N/A - 34 watts Standby/On
Power Consumption 56 watts / 326 watts 1-watt/Rated op
Mains Voltage Variation 241–257 volts Min–Max
Marantz PM KI Pearl Integrated Amplifier - Test Results
Channel Load (Ω) 20Hz
(watts)
20Hz
(dBW)
1kHz
(watts)
1kHz
(dBW)
20kHz
(watts)
20kHz
(dBW)
1 8Ω 122 20.8 122 20.8 121 20.8
2 8Ω 112 20.5 112 20.5 110 20.4
1 4Ω 203 23.1 204 23.1 190 22.8
2 4Ω 173 22.4 175 22.4 160 22.0
1 2Ω 267 24.3 283 24.5 229 23.6
2 2Ω 212 23.3 237 23.7 200 23.0
Note: Note: Figures in the dBW column represent the output level, in decibels, referred to one watt output.
avhub.com.au