● Two totally identical power amplifier circuits driven in parallel ● 16 parallelpush-pull arrangement of MOS-FET devices in output stage ● Input stage
configured as double instrumentation amplifier ● Double MCS+ circuit andcurrent feedback topology in amplification stage ● Support for bridged use oftwo M-6000 units with even higher output power ● Power supply with massivehigh-efficiency 900-VA toroidal transformer and large filtering capacitors

The ultimate power MOS-FET machine – This super capable yet astonishingly
nimble monophonic power amplifier features a double instrumentation amplifier
setup for fully balanced signal transmission, augmented by a Double MCS+ circuitand current feedback topology. Experience outstanding sound and drastically
improved performance parameters including excellent S/N ratio and minimal
THD. A hefty power supply and 16 power MOS-FETs arranged in a parallel pushpull configuration deliver 1200 watts (music signal) into an ultra-low 1-ohm load.
The M-6000 was born out of a thorough re-evaluationof the power amplifier from a new vantage point. Aiming
for nothing less than the ultimate in sound quality, thismonophonic power amplifier with its massive heat sinks
on both sides stands as an impressive achievement.
The decisive difference to conventional designs liesin the fact that the M-6000 possesses two completely
identical power amplifier circuits which are driven inparallel. Kept entirely separate and mounted on the left
and right sides of the chassis, these circuits deliver output
current reserves on a previously almost unheard-of level.
A damping factor rating of more than 500 demonstrates
that this amplifier is capable of driving even the mostdifficult, ultra-low impedance loads with ease.
In a high-output amplifier, the operating conditions of thepower supply and the thermal conditions can change
dramatically from one moment to the next. To ensurestable circuit operation under such demanding conditions
must therefore be a top priority. In the M-6000, twomajor factors which made driving two power amplifier
units in parallel possible are the use of power MOSFET devices, and the Double MCS+ circuit topology.
Power MOS-FETs are renowned for their excellent
high-frequency characteristics, and they exhibit negative
thermal behavior by design. This makes it easy to control
the temperature balance between two power amplifier
units, achieving stable operation even when the load andoperating conditions change dramatically. The Double
MCS+ circuit works perfectly together with the current
feedback approach to ensure perfectly controlled phasecharacteristics over the entire audible range and evenbeyond, extending into the ultra high frequency area. This
results in further improved overall performance.

■ 16-parallel push-pull arrangement of power MOSFETs delivers linear power progression: 1200 watts(music signal) into 1 ohm, 600 watts into 2 ohms, 300
watts into 4 ohms, or 150 watts into 8 ohms.
■ Strong power supply with large high-efficiency 900 VA
toroidal transformer and massive filtering capacitors(48,000 μF x 2).
■ Printed circuit boards made from Teflon with low
dielectric constant and minimum loss.

High-efficiency toroidal transformer

Filtering capacitors* Teflon is a registered trademark of DuPont USA.

■ Bridged operation of two M-6000 units allows upgrade to monophonicamplifier with even higher power, delivering 2400 watts into 2 ohms
(music signal), 1200 watts into 4 ohms, or 600 watts into 8 ohms.
■ Double MCS+ (Multiple Circuit Summing) topology and current feedback
topology work together for even better S/N ratio.

Balanced inputs■ 4-stage gain selector (MAX, –3 dB, –6 dB,–12 dB) minimizes residual noise.
■ Fully balanced circuitry reliably shuts out
external noise.
■ Phase selector with Normal and Reverse
settings.
■ Large analog peak-reading meter:

Gain control selector

Meter circuitry and protection circuitry assembly● Meter operation and illumination on/offswitch● Switchable peak hold time: 3 seconds or infinite■ Instrumentation amplifier principle enables fully balanced signal
paths throughout the unit.
■ Input selector button (balanced/unbalanced) on front panel.
■ Massive speaker terminals also accept Y lugs.

Speaker terminal assembly

Bias stabilizer
circuit

Bias stabilizer
circuit

Bias stabilizer
circuitn Two power units, each with an 8-parallelpush-pull arrangement of power MOS-FET
devices, are driven in parallel.

Bias stabilizer
circuit

Bias stabilizer
circuitOutput current (A)Bias stabilizer
circuit

Bias stabilizer
circuit

Bias stabilizer
circuit

Bias stabilizer
circuitOutput voltage (V)@ 1-ohm operation possible with music signals only
Bias stabilizer
circuitFigure 1 Circuit diagram of amplifier section

Figure 2 Load impedance vs. output power(output voltage/output current)Instrumentation amplifier configuration and further refined Double MCS+ circuit
Double instrumentation amplifier configuration
allows fully balanced signal paths throughout

Double MCS+ in amplifier stage furtherimproves S/N ratio

Current feedback assures excellent phasecharacteristics in high range

The M-6000 employs latest instrumentation amplifier
topology in a dual configuration. From the input
terminal right through to the output of the powerstage, the signal is handled only by balanced
amplifiers. This not only eliminates internal noise anddistortion components, it also makes the amplifier
extremely resistant to changes in the external
environment, resulting in dramatically improved
stability and reliability.

The input stage of the amplifier section features
another Accuphase innovation. Double MCS+ makes
ample use of cascode drive circuits and dedicateseach component to a clearly defined task, thereby

As shown in the illustration, the M-6000 uses the output
signal current rather than voltage for feedback. Since
the impedance at the current feedback point is very
low, there is almost no phase shift. A minimal amountof NFB therefore results in maximum improvement ofcircuit parameters.

(-) input
bufferCurrent adder
I/V
converter

AmplifierOutputTrans-impedance amplifier
Signal input stage(+) input
bufferPower amplifier stage

Current NFB
network

ensuring stable performance. Four circuits for
amplifying the input signal are connected in parallel tokeep distortion to a minimum and to further enhance
S/N ratio and other parameters. The resulting levelof sound quality is simply stunning.

Instrumentation amplifier principle

Principle of current feedback amplifier■ Power amplifier assembly with 8-parallel push-pull power
MOS-FET arrangement for output stage mounted directly
to large diecast aluminum heat sink, also comprising MCS+
circuitry and current feedback amplifier. Two completely
identical circuits are used.

■ Using four M-6000 units, bridged operation or bi-amping is possible.
■ Connect the input signal either to the balanced or the unbalanced inputs.

Example for bridged connection
Bridged operation of two M-6000 units allows upgrading
to a monophonic amplifier with even higher power.

Left speaker✽ For connecting the SPEAKER terminals to each other,use speaker cable of same grade as for other speakerconnections.
✽ Set the phase selector switches of the left-channel andright-channel units to INVERTED (reveres phase).

Example for bi-amping connection
Left speaker

Right speaker

Right speaker

In a bi-amped setup, the speaker units for the LOW
frequency range and HIGH frequency range are driven
by separate amplifiers, for optimum sound quality.
✽ The speakers must have a built-in crossover networkand separate inputs for LOW and HIGH range.
✽ Set the phase selector switches of all four units toNON-INVERTED(normal phase).

Preamplifier

Preamplifier■ Front Panel■ Parts selected for high sound quality and reliability■ Major signal path parts are gold-plated

Guaranteed Specifications[Guaranteed specifications are measured according to EIA standard RS-490.]● Continuous Average Output 1,200 watts into 1 ohm (✽)
Power (20 - 20,000 Hz)
600 watts into 2 ohms
300 watts into 4 ohms
150 watts into 8 ohms
Output in bridged mode (using two M-6000 units)
2,400 watts into 2 ohms (✽)
1,200 watts into 4 ohms
600 watts into 8 ohms
Note: The rating marked (✽) is for music signals only.
● Total Harmonic Distortion
0.05% with a 2-ohm load
0.03% with a 4 to 16-ohm load

■ Rear Panel● Intermodulation Distortion

0.01%● Frequency Response
At rated continuous average output: 20 - 20,000 Hz +0, –0.2 dB
At 1 watt output:
0.5 - 150,000 Hz +0, –3.0 dB

Hold time indicator
Power meter (dB and % indication)
Input indicator
Meter illumination/operation/hold time selector
OFF / NORMAL / 3 SEC /Power switch
Input selector button
BALANCED UNBALANCED
Gain selector
MAX, –3 dB, – 6 dB, –12 dB

Unbalanced inputs(One is for signal output during bridged operation)
Speaker terminals
Balanced inputs(One is for signal output during bridged operation)
Non-inverted (+)
GroundInverted (–)
Phase selector switch
NON-INVERTED (normal phase)
INVERTED (reverse phase)AC power connector● Gain28.0 dB (GAIN selector in MAX position)● Gain Selection

MAX, –3 dB, –6 dB, –12 dB● Output Load ImpedanceContinuous output: 2 to 16 ohms
With music signal: 1 to 16 ohms

● Damping Factor

500● Input Sensitivity

1.38 V for rated continuous average output
0.11 V for 1 watt output● Input Impedance

Balanced:40 kilohms
Unbalanced: 20 kilohms● Signal-to-Noise Ratio(A-weighted)

120 dB with input shorted, at rated continuous
average output● Output Level Meter–60 to +3 dB (dB/% indication)
Logarithmic compression scale
Display illumination off switch
Peak hold time select: 3 seconds,● Power Requirements

AC120 V/230 V (Voltage as indicated on rear panel)
50/60 Hz● Power Consumption

180 watts idle
550 watts in accordance with IEC 60065● Maximum Dimensions

Width: 465 mm (18-5/16")
Height: 220 mm (8-11/16")
Depth: 500 mm (19-11/16")● Mass38.5 kg (84.9 lbs) net
48.0 kg (105.8 lbs) in shipping carton
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, and the circuit breaker current rating depend on the voltage rating and destination country.

Supplied Accessories● AC power cord

●Specifications and design subject to change without notice for improvements.

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