● Output stage with 8-parallel push-pull power MOS-FETs delivers high power:
700 watts x 2 into 1 ohm with music signals ● Input stage featuring instrumentation amplifier topology ● Further refined MCS+ circuit ● Current feedback
principle combines excellent sound quality with total operation stability● Bridged connection mode allows upgrading to monophonic amplifier ● Powersupply with highly efficient toroidal transformer and large filtering capacitors

Stereo power amplifier with power MOS-FET devices – Instrumentation amplifier
principle allows fully balanced signal paths. Further refined MCS+ and current
feedback topology assure outstanding S/N ratio, minimum distortion, and excellent
all-round performance, resulting in superb sound quality. 8-parallel push-pullarrangement of MOS-FET power transistors delivers 700 watts x 2 (with musicsignals) into ultra-low loads of one ohm. 4-step gain control minimizes residual noise.
The Class AB Monophonic Power Amplifier
M-6000 using power MOS-FETs in its output stage
has been highly acclaimed both in Japan andabroad for its excellent sound quality andperformance. The P-6100 is a stereo version ofthis model, inheriting its outstanding design
technology. It features instrumentation amplifier
topology and a further refined MCS+ circuit, aswell as the current feedback principle to minimize
noise. Only specially selected top-grade materials
and parts are used throughout. The result is ahigh-end stereo amplifier that is bound to impress.
In the output stage, high-power MOS-FET devices
renowned for their great sound and utter reliability
are used. MOS-FETs have excellent frequency
response and high input impedance which reduces
the load on the preceding driver stage. They also
have perfect thermal stability. In each channel ofthe P-6100, 16 of these devices are arranged in an
8-parallel push-pull configuration. This brings out
the musical potential inherent in the source withabsolute clarity and stunning authority.
The massive heat sinks on both sides of thechassis achieve efficient dissipation of thermalenergy and ensure stable operation. This allows
the amplifier to deliver an amazing 700 watts ofpower per channel into an ultra-low impedanceload of 1 ohm (music signals). The linear powerprogression with a rating of 440 watts into 2 ohms,
220 watts into 4 ohms, and 110 watts into 8 ohms
means that the amplifier can competently handle
even speakers with very low impedance or withdifficult impedance curves. Using the P-6100 in
bridged mode creates a monophonic amplifier witheven more impressive power capability, rated for
1400 watts into 2 ohms (music signals). This
performance is sustained by a massivehigh-efficiency toroidal transformer housed in analuminum enclosure with heat dissipation fins andcomplemented by two large 56,000 µF filteringcapacitors. Even the most stringent power
demands are easily met by this configuration.

■ Power MOS-FET devices in 8-parallel push-pullarrangement deliver 700 watts per channel into 1ohm (music signals only), 440 watts into 2 ohms,
220 watts into 4 ohms, or 110 watts into 8 ohms.
■ Bridged mode (using two P-6100 units for a stereosystem) allows conversion into monophonic amplifier
with 1,400 watts into 2 ohms (music signals only), 880
watts into 4 ohms, or 440 watts into 8 ohms.

Power MOS-FET devices■ Robust power supply with high-efficiency toroidaltransformer and two large 56,000 µF filtering capacitors.
■ Input selector button (Line/Balanced) on frontpanel.

Input selector button■ 4-step gain selector minimizes residual noise(MAX, -3 dB, -6 dB, -12 dB).

High-efficiency toroidal transformer■ Large analog peak-reading output power meters●●

Meter operation and illumination on/off switch
Switchable peak hold time: 3 seconds or infinite

Gain control selector■ Printed circuit boards made from glass fluorocarbon
resin with low dielectric constant and low loss.
■ Fully balanced input stage topology reliably
shuts out external noise.
■ Redesigned NFB circuitry keeps output impedance
extremely low, resulting in higher damping factor
for further improved sound quality.

Meter selector
Filtering capacitors■ Mode selector makes it easy to switch between
dual mono, stereo, or bridged operation.
■ Two sets of massive speaker terminals accept
also Y lugs.
■ Major signal path parts are gold-plated.

Assembly with line and balanced input connectors

Gold-plated parts
Assembly with meter circuitry, protection circuitry etc.

Large speaker terminals

Instrumentation amplifier* 1-ohm operation possibl
with music signals onlyBias
stabilizer+ B3

Power MOS-FETs in 8-parallelpush-pull configuration+ B1

REGULATOR

Q1
Q5

Q9

Q 13+ B2+ INPUT+–Q 17
Q3

Q7

Q 11

Q 19

Q 21

Q 23

Q 25

Q 27

Q 29

Q 31

Q 33

Q 35

Q 15

NFB
NETWORKOUTPUTNFBNETWORKBiasstabilizer

Biasstabilizer
NFB
NETWORKSPEAKERTERMINAL

Output current (A)Biasstabilizer

GAIN CONTROLCIRCUIT

Q2–+Q6

Q 10

Q 14

Q8

Q 12

Q 16Q 18Q 20Q 22Q 24

Q 26

Q 28

Q 30

Q 32

Q 34

Q 36

– INPUT– B2
Q4
REGULATOR– B1– B3
Biasstabilizer
NFB
NETWORKGain control

MCS＋（Multiple Circuit Summing）
Figure 1 Circuit diagram of amplifier section (one channel)

Output voltage (V)Figure 2 Load impedanc(output voltageInstrumentation Amplifier Configuration and Further Refined MCS+ Topology
Instrumentation amp configuration allows
fully balanced signal paths

Further refined MCS+ topology for even lowernoise

The P-6100 features the highly advanced
instrumentation amplifier principle whereby all
signal paths from the inputs to the power amp
stage are fully balanced. This results inexcellent CMRR (common mode rejection ratio)
and minimal distortion. Another significant

Accuphase's original MCS (Multiple Circuit Summing)
principle uses a number of identical circuits connected inparallel to achieve superior performance characteristics.
MCS+ is a further refined version of this approach.
Improvements in the bias circuitry of the input-stage
buffer amplifier result in greater stability. This in turnmakes it possible to extend the parallel operation
approach to the class-A drive stage of the current/voltage
converter, thereby further lowering the noise floor.

Signal input stage＋ INPUTPower amplifier stage＋

feedback point is very low, there is almost nophase shift. Phase compensation can therefore
be kept at a minimum. A slight amount of NFB
results in maximum improvement of circuit
parameters.

Current adder+ input
buffer/V
converter

Current NFB
network

Principle of current feedback amplifier＋
NFB
NETWORK−

Output- input
buffer−NFB
NETWORK

AmplifierTrans-impedance amplifier

OUTPUTNFBNETWORK

Phase selector for balanced input−− INPUT＋● In

Instrumentation amplifier configuration

advantage is that external noise and otherexternal influences are virtually shut out. The
result is a drastic improvement in power
amplifier operation stability and reliability.

lece vs. output power
e/output current)

Current feedback circuit topology assures
excellent phase characteristics in high range
In the P-6100, the signal current rather than themore conventionally used voltage is used forfeedback. Since the impedance at the current

the factory default condition, theswitch is set to the left side (pin e +).

● If the balanced output of theconnected preamplifier hasa pin w + arrangement,

the switch can be set tothe right side.

■ Power amplifier assembly with 8
parallelpush-pull
power
MOS-FET transistor pairs perchannel mounted directly tolarge heat sinks, MCS+ circuitry,
and current feedback amplifier■ Using two P-6100 units, bi-amping or bridged connection can be realized, for even higher performance. ■In this case, only the LEFT input (BALANCED or LINE) of each unit is used.

Connection example for bi-amping setup
Left loudspeaker

Connection example for bridged setup

Right loudspeaker

Left loudspeaker

In a bi-amped setup, the speaker units for the LOW
frequency range and HIGH frequency range are driven
by separate amplifiers, for enhanced sound quality.
＊ A speaker with a built-in crossover networkand separate inputs for LOW and HIGH
range is required.

− ○＋
○
− ○＋
○
LOW HIGH

−

R＋−

L＋−

R＋−

In bridged mode, the P-6100 becomes a monophonicamplifier with even higher power output.
− ○＋
○− ○＋
○
LOW HIGH＋○To left channel input

LEFT ＋To left channel input

L
Mode selector ofboth P-6100 units
set to DUAL
MONO positione＋○P-6100
for rightchannel

RPreamplifierw

RIGHT ＋LEFT ＋−○P-6100
for leftchannelTo left channel input

L＊ The − speaker terminals of the P-6100 are
not used.

RIGHT ＋

P-6100
forfor rightleftchannel■Front panel q−○L＋

P-6100for leftchannel
To left channel input

Right loudspeaker

RMode selector ofboth P-6100 units
set to BRIDGE
position

Preamplifierr

Guaranteed Specifications[based on the EIA RS-490 test standard]● Rated Continuous Average Output Power (at 20 - 20,000 Hz)
Stereo use
700 W/ch 1-ohm load＊(both channels operating 440 W/ch 2-ohm loadsimultaneously)
220 W/ch 4-ohm load
110 W/ch 8-ohm load
Monophonic use(Bridge connection)

1,400 W
880 W
440 W

2-ohm load＊
4-ohm load
8-ohm load

＊These loads are for music signals only.
● Total Harmonic Distortion Stereo use (both channels operating simultaneously)
0.05% 2-ohm load
0.03% 4 to 16 ohm load
Monophonic use (Bridge connection)
0.03% 4 to 16 ohm loadtyu■Rear panelio● IM Distortion

0.01%● Frequency Characteristics At rated continuous average output: 20 – 20,000 Hz +0, -0.2 dB
At 1-W output:
0.5 – 160,000 Hz +0, -3.0 dB!0

● Gain28 dB (when GAIN switch set to MAX)
(Same for both stereo and monophonic use)

● GAIN switch settings

MAX, -3 dB, -6 dB, -12 dB● Load Impedance

Stereo use:
2 – 16 ohms For music signals only: 1-ohm (for stereo)
Monophonic use: 4 – 16 ohms and 2-ohm (mono) loads are also supported.

● Damping Factor

500 (Same for both stereo and monophonic use)

● Input Sensitivity (at 8-ohm load, with GAIN switch set to MAX)
Stereo use
1.18 V at rated continuous average output
0.11 V at 1-W output
Monophonic use
2.36 V at rated continuous average output
0.11 V at 1-W output!1!2!3q Hold time indicatorw Speaker indicatore Left/right channel power meters(dB and % scale)r Function indicator
LINE, BALANCED, BRIDGEt Meter operation/illumination switch
OFF, NORMAL, 3 SEC, <infinite>y Speaker selector
A: ON/OFF, B: ON/OFFu Power switch
i Input selector button LINE, BALANCED!4● Input Impedance

Balanced:
40 k ohms
Line (Unbalanced): 20 k ohms

● S/N (A-weighted)

120 dB when GAIN switch set to MAX
125 dB when GAIN switch set to -12 dB(At rated continuous average output)● Output Meters

Logarithmic compression type; illumination turn-off capability;-60 dB to +3 dB (indication in both dB and %);switchable peak hold time: 3 sec, ∞● Power Requirements

AC 120 V/230 V, 50/60 Hz(Voltage as indicated on rear panel)● Power Consumption

170 W (with no input)
670 W in accordance with IEC 60065● Maximum Dimensions

WidthHeightDepth● Mass42.7 kg (94.1 lbs) net
51.0 kg (112.4 lbs) in shipping carton!5 ★

o Gain selector
MAX, -3 dB, -6 dB, -12 dB!0 Left/right speaker terminals
Two sets: A and B!1 Line inputs!2 Balanced inputs
Pin w : -, Pin e : +(Can be switched with phase selector button !3)!3 Balanced input phase selector switch!4 Mode selector
DUAL MONO, NORMAL, BRIDGE!5 AC power supply connector★

465 mm (18-5/16")
221 mm (8-11/16")
499 mm (19-5/8")

Remarks
This product is available in versions for 120/230 V AC. Make sure that the voltage shown on the rear panel matches the AC line voltage in your area.
The shape of the AC inlet and plug of the supplied power cord depends on the voltage rating and destination country.
■ Supplied accessory●●AC power cord

Specifications and design subject to change without notice for improvements.
K1005YPRINTED IN JAPAN

851-00198-00（B1）