Specifications

ManualsBrandsMarantz ManualsAmplifierPM-KI-PEARL

Australian

O N T E S T

Newport Test Labs

f you know anything at all about the

history of this ampliﬁer, you may well

be wondering why I am reviewing it at

all. First, you have to know that Ken

Ishiwata has been a spokesman, designer and

‘brand advisor’ for Marantz for 30 years. He

has put his initials on various Marantz prod-

ucts over the years, all of which have been es-

pecially ‘souped-up’ versions of existing ones.

This time around, the model he’s souped-up

is the new PM-15S2 and, because it’s his 30th

anniversary at Marantz, it’s not a ‘Signature

Model’ as such, but a ‘K.I. 30th Anniversary’

model. To celebrate this milestone, Ishiwata

was apparently allocated a larger-than-usual

budget for his high-performance modiﬁca-

tions, so this 30th Anniversary model is more

‘souped-up’ than usual. It will also be a ‘Lim-

ited Edition’ by virtue of the fact that it will

have to cease production at the end of the

year. US reviewer Michael Fremer says he was

told that only 500 of this particular model

will be made, but I could not independently

verify that claim.

The equipmenT

Because the single most expensive part of any

ampliﬁer is the exterior casing and metal-

work, Ishiwata has used the PM-15S2’s casing

for the PM-KI-Pearl but, as is his wont, he has

copper-plated the chassis and rear plate (for

reduced ground impedances and eddy cur-

rents) and also used a 5mm top plate as well

as a heavier-gauge bottom plate so there are

some ‘exterior’ differences. Inside the chassis,

even though there are the same PCBs and

many individual components shared with

the PM-15S2 there are also differences, with

the PM-KI-Pearl sporting a larger, higher-ca-

pacity toroidal transformer, higher-quality

capacitors throughout (including the large

electrolytics in the power supply), better-

quality diodes and closer-tolerance

resistors. He’s also used up-specced

versions of Marantz’s HDAM-SA3

ultra-high-speed ampliﬁer modules,

and hand-selected the ones used in

the phono stage.

One circuit feature of the PM-KI-

Pearl dubbed ‘F.C.B.S.’ initially mysti-

ﬁed me completely. The initials stand

for ‘Floating Control Bus System.’

What the circuit is designed to do is

allow you to link up to four PM-KI-

Pearl ampliﬁers so you can bi-amp a

stereo pair of speakers (using two PM-

KI-Pearls) or use three PM-KI-Pearls

to power a 5.1-channel home theatre

system, or four for a 7.1-channel

system. While I can see the sense of

this approach, a stack of four PM-KI-

Pearls would be intimidatingly high, at around

1.5 metres… assuming you follow Marantz’s

recommendations for ventilation. (Note that

the rather less expensive PM-15S2 also has

F.C.B.S., so for multi-channel use, you could

save quite a bit of dough by using a single PM-

KI-Pearl for the front left and right channels,

and a pair of PM-15S2s for the centre and rear

channels.)

As you can see from the front panel,

although the PM-KI-Pearl can be operated via

remote control (it’s actually essential for the

F.C.B.S. mode), there are sufﬁcient manual

controls on the front panel that it won’t

matter if you lose it. The bass and treble tone

controls to the right of the power on/off but-

ton can be switched in or out of circuit, but

the button to do this is ‘way off to the left,

which didn’t seem very intuitive to me. Also,

from the size of the bass and treble controls, it

would appear Ishiwata isn’t keen that you use

them, because they are so small they’re actu-

ally quite difﬁcult to grip and to turn.

The ‘Speakers’ button on the front panel

merely switches the speakers on or off, so you

can listen with headphones—you don’t get

A–B speaker switching. The ‘Phono’ button,

on the other hand, does switch gain stages,

so you can use a low-output (usually moving

coil) or a high-output (usually moving-mag-

net) phono cartridge. However, to select the

‘Phono’ input, you need to use the large, con-

tinuous, rotary input selector. This switches

through CD, Line-1, Line-2, Recorder1, Re-

corder2, and Phono and unlike some continu-

ously rotary controls, it will continue to cycle

through in this order if you continue to rotate

the control in a clockwise direction—there’s

no need to reverse direction and go anti-clock-

wise if you don’t want to. This type of control

Marantz PM-KI-Pearl

INTEGRATED AMPLIFIER

Power Output: Single channel driven into

8-ohm, 4-ohm and 2-ohm non-inductive

loads at 20Hz, 1kHz and 20kHz. [PM-KI]

Summary of content (5 pages)

PAGE 1
ON TEST Marantz PM-KI-Pearl Integrated Amplifier I f you know anything at all about the history of this amplifier, you may well be wondering why I am reviewing it at all. First, you have to know that Ken Ishiwata has been a spokesman, designer and ‘brand advisor’ for Marantz for 30 years. He has put his initials on various Marantz products over the years, all of which have been especially ‘souped-up’ versions of existing ones.
PAGE 2
Marantz PM-KI-Pearl Integrated Amplifier depends on using internal relays: the ones inside the PM-KI-Pearl click rather loudly! The ‘ATT’ button you can see on the front panel would normally be known as a ‘Mute’ button, except that on this amplifier, Marantz allows you to choose lesser degrees of attenuation than a total Mute. The factory default is –20dB, but you can increase this to either –40dB or all the way to ‘Infinity’ (aka ‘Mute’).
PAGE 3
Marantz PM-KI-Pearl Integrated Amplifier circuitry, but this never transpired, despite me leaving the amplifier operating continuously for more than a week, and there being several +30° days during that time. However, when I deliberately blocked the vents just to see what would happen, the casing temperature did rise quite alarmingly, so I would certainly pay attention to the instructions in the Owners Manual regarding the spaces required around the amplifier for ventilation.
PAGE 4
LAB REPORT Marantz PM-KI-Pearl Integrated Amplifier SEE REVIEW ON PAGE 24 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.
PAGE 5
LAB REPORT Marantz PM-KI-Pearl Integrated Amplifier was inter-channel phase, with figures so low that you can read them for yourself in the test result chart. Total harmonic distortion (THD) was vanishingly low at 1-watt output levels, as you can see from Graph 1 (into 8Ω) and Graph 2 (into 4Ω). In both cases the second harmonic distortion component is sitting down at around –95dB (0.001%) and the third harmonic at –105dB (0.0005%).