● Pure Class A operation delivers quality power: 30 watts x 2 into 8 ohms ● Power MOSFET output stage features 3-parallel push-pull configuration ● Instrumentation amplifier principle
used in input stage ● Amplification stage implements further evolved MCS+ topology ● Current
feedback principle combines stable operation with outstanding sound quality ● Bridged
connection mode allows upgrading to monophonic amplifier ● Strong power supply withmassive high-efficiency transformer and large filtering capacitors ● 4-stage gain control

Redefining Essential Excellence
Impressive Baseline Pure Class A Stereo
Power Amplifier. Input stage features fully balanced signal paths realized with ultra
low noise instrumentation amplifier topology. MCS+ design and current feedbackin amplification circuitry deliver outstanding S/N ratio and other performanceparameters for improved sound quality. Robust power supply and power
MOS-FET devices in triple-parallel push-pull configuration sustain power output of
150 watts per channel (music signals) down to impedances as low as 1 ohm. Output
stage with further lowered impedance realizes a damping factor of 400.
Pure Class A amplifiers from Accuphase have a longand distinguished tradition and have attained widely
acclaimed levels of performance combined withreliability and impeccable sound quality. Audiophiles
the world over continue to hold them in high esteem.
The Pure Class A Monophonic Power Amplifier
A-200 introduced on the occasion of the company's
40th anniversary, and the high-end Pure Class A
Stereo Power Amplifier A-70 opened up new realmsof sonic excellence and have become legendary as
reference audio devices. The new A-36 inherits
many of the outstanding design technology featuresdeveloped for the higher-end models. It redefines thebaseline for pure class A power amplifiers and represents the same unwavering attention to detail anddedication to sound quality for which Accuphase isjustly famous.
Latest instrumentation amplifier topology allows therealization of fully balanced signal paths, while theMCS+ circuitry combined with current feedback
topology and carefully selected high-grade materials
assure further enhanced performance and soundquality. In the output stage, power MOS-FETs
renowned for their excellent frequency response,
sonic performance, and superior reliability are used
in a triple parallel configuration and driven in pureclass A. This is sustained by the strong power supply
featuring a massive transformer and two large
47,000 μF filtering capacitors. Output power in eachchannel is rated for an impressive 150 watts into
1 ohm, 120 watts into 2 ohms, 60 watts into 4 ohms,
and 30 watts into 8 ohms. Even speakers with ultralow impedance or drastic fluctuations in impedance
curve can be driven reliably by this impressive amplifier. In the output circuitry, MOS-FET switches areused in place of relays, to eliminate mechanicalcontacts and improve long-term reliability. Top-grade
materials, sophisticated circuit pattern technology,
and various other measures result in low impedance
and allow the realization of a damping factor of 400,
which represents a two-fold improvement over theA-35. The well-proven analog power meters areequipped with a sensitivity selector for easy observation of low power levels, and a peak hold function
has been newly added.

Large speaker terminals

Q1
Q5＋Q7
Q3FEEDBACK
NETWORKQ9Q 11Q 15+ B2Q 17Q 19

Q21Q23

Q25BIAS
STABILIZERCIRCUIT＋SPEAKERTERMINAL

Q6Q 10Q 14Q8Q 12Q 16Q4OUTPUTBIAS
STABILIZERCIRCUITBIAS
STABILIZERCIRCUIT

Q2200180

159W

140BIAS
STABILIZERCIRCUIT

Q 18

Q 20

Q22120W

8060W

4060W

2030W

B2

REGULATOR

104W

100

Max. output power
Rated output power

Q26

Q24150W

12060
NFB
NETWORKFEEDBACKNETWORK

INPUT

200W

+ B1Q 13GAIN CONTROLCIRCUIT−

Output power
characteristics

160
REGULATOR−

Line and balanced input connectors

Power amplification stage
MCS+ (Multiple Circuit Summing)

BIASSTABILIZERCIRCUIT+ INPUT

Protection and meter circuit assembly

Output power (W)Signal input stage■ 3-parallel push-pull arrangement of power
MOS-FETs delivers 150 watts (music signal)
into 1 ohm, 120 watts into 2 ohms, 60 watts
into 4 ohms, or 30 watts into 8 ohms.
■ Strong power supply with large high-efficiency
transformer and two 47,000 μF filtering capacitors.
■ Instrumentation amplifier principle for power
amplifier input stage allows fully balanced
Power transformer
Filtering capacitors
signal transmission. MCS+ topology further improves S/N ratio.
■ Bridging allows upgrade to monophonic amplifier with evenhigher power, delivering 300 watts into 2 ohms (music signal),
240 watts into 4 ohms, or 120 watts into 8 ohms.
■ Operation mode switch supports dual mono operation andallows bi-amping connection.
■ Damping factor doubled to 400 contributes to enhanced
Input selector button Operation mode selector
sonic definition.
■ Analog power meters.
Meter operation/light on/off switch, peak hold/normal
operation selector, sensitivity selector (0 dB, -20 dB).
■ 4-stage gain selector (MAX, -3 dB, -6 dB, -12 dB)
also minimizes residual noise.
■ Semiconductor (MOS-FET) switches used forGain control selector
Meter controls
protection circuitry.
Prevent contact problems and ensure long-term reliability.
Eliminating mechanical contacts fromsignal path also further enhances soundquality.
■ Balanced input phase selector switch.
If balanced input of preamplifier uses
pin 2 positive configuration, this switch
Speaker selector buttons
MOS-FET switches
Phase selector
can be used for proper matching.
■ Two sets of large speaker terminals (A / B) also accept Y lugs.

8Ω

4Ω
2Ω
1Ω
Impedance (Ohms)

B1NFB
NETWORKFig. 1 Circuit diagram of amplifier section (one channel)

Power MOS-FETs

Parts selected for high sound quality and reliability

Instrumentation amplifier configuration and further refined MCS+ topology
Amplification stage features instrumentation
amplifier topology for fully balanced signal paths
The instrumentation amplifier principle ensuresthat all signal paths from the inputs to thepower amp stage are fully balanced. This notonly results in excellent CMRR (Common ModeRejection Ratio) and minimal distortion, it also
makes the amplifier highly resistant against
external noise and other external influences.
The result is a drastic improvement in operation
stability and reliability.
Signal input stage+ INPUTPower amplifier stage+

TRANS-IMPEDANCE AMPLIFIER−INPUT

BUFFER/V

CONVERTER

CURRENT ADDERBUFFERAMPLIFIEROUTPUT

CURRENT NFBNETWORKOUTPUT–FEEDBACKNETWORK‒ INPUTAs shown in the illustration, the A-36 uses the output
signal current rather than voltage for feedback.
Since the impedance at the current feedback pointis very low, there is almost no phase shift. A minimal
amount of NFB therefore results in maximum
improvement of circuit parameters.

Principle of current feedback
amplifier–GAIN CONTROLCIRCUIT

Current feedback principle assures excellent
phase characteristics in high range＋INPUT+FEEDBACK
NETWORKMCS+ is a further refined version of this approach.
By extending parallel operation to the class-Adrive stage of the current/voltage converter, thenoise floor has been lowered further.

–+Instrumentation amplifier principle

Further refined MCS+ topology for evenlower noise
Accuphase’s original MCS (Multiple CircuitSumming) principle uses a number of identicalcircuits connected in parallel to achieve
superior performance characteristics.

Power amplifier assemblyPower amplifier assembly with
3-parallelpush-pull
power
MOS-FET arrangement mounted
directly to large heat sink, also
comprising MCS+ circuitry andcurrent feedback amplifier.

■ Using two A-36 units, upgrade to bridged operation or bi-amping is possible. ■ Use the LEFT (BALANCED or LINE) input connectors for both units.

Connection example for bi-amping setup

Connection example for bridged setup
Left loudspeaker

Right loudspeaker

Left loudspeaker

When the operation mode selector is set
to bridged mode, the A-36 becomes amonophonic amplifier with even higher
power output.
− speaker terminals of the A-36 are not used.
＊The ●LOWRIGHT ＋

A-36 for left channel

LEFT ＋To left channel input

BRIDGE LED on
front panel lit on
both A-36 units

A-36 for right channel

To left channel input

LHIGH

LEFT ＋

RIGHT ＋

Right loudspeaker

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.

− ＋ − ＋A-36 for left channel

Operation mode
selector set to
BRIDGE on bothA-36 units

ROperation mode
selector set to
DUAL MONO on
both A-36 units

Preamplifier■ Front Panel

A-36 GUARANTEED SPECIFICATIONS

q Right/left-channel output power meters w Function indicator LEDs
(dB and percent indication, switchable)-20 dB METER / SPEAKER A,B / LINE /BALANCED / BRIDGE[Guaranteed specifications measured according to EIA standard RS-490]● Continuous Average Output Power (20–20,000 Hz) Note: Load ratings marked (＊) apply only tooperation with music signals.

150 watts per channel
into 1 ohm (＊)
120 watts per channel
into 2 ohms
60 watts per channel
into 4 ohms
30 watts per channel
into 8 ohms
Monophonic operation
300 watts
into 2 ohms (＊)(bridged connection)
240 watts
into 4 ohms
120 watts
into 8 ohms
● Total Harmonic
Stereo operation (both channels driven)
Distortion
0.05%
with 2 ohm load
0.03%
with 4 to 16 ohm load
Monophonic operation (bridged connection)
0.05%
with 4 to 16 ohm load
● Intermodulation Distortion 0.01%● Frequency Response At rated output: 20 – 20,000 Hz +0, -0.2 dB
At 1 watt output: 0.5 – 160,000 Hz +0, -3.0 dB
28.0 dB (with GAIN selector at MAX)
● Gain(Stereo and monophonic operation)
MAX, -3 dB, -6 dB, -12 dB● Gain Selection● Output Load impedance
Stereo operation:2 to 16 ohms
Monophonic operation: 4 to 16 ohms
With music signals only, 1-ohm loads arepermissible for stereo operation and 2-ohm loads
for monophonic operation.
● Damping Factor
400● Input Sensitivity (with 8-ohm load, GAIN selector in MAX position)
Stereo operation:
0.62 V for rated continuous average output (30 W)
0.11 V for 1 watt output
Monophonic operation: 1.23 V for rated continuous average output (120 W)
0.11 V for 1 watt output● Input Impedance
Balanced: 40 kilohms Line: 20 kilohms● Signal-to-Noise Ratio (A-weighted, input shorted)
112 dB (GAIN selector at MAX)
120 dB (GAIN selector at -12 dB)
At rated continuous average output● Output Level Meters-40 dB to +3 dB (indication in dB and %)Logarithmic scale
Operation selector: OFF / NORMAL / HOLD (∞)
Meter sensitivity selector (-20 dB)＊Monophonic operation: same value displayed forleft/right● Power Requirements AC 120 V/230 V, 50/60 Hz(Voltage as indicated on rear panel)● Power Consumption
155 watts idle
270 watts in accordance with IEC 60065● Maximum Dimensions Width465 mm (18.31")
Height
171 mm (6.73")
Depth425 mm (16.73")● Mass22.8 kg (50.27 lbs) net
29.0 kg (63.93 lbs) in shipping carton
Stereo operation(both channels driven)e Meter selectory Power switch

r -20 dB buttont Speaker selector buttons

OFF / NORMAL /HOLD (∞)

A: ON/OFF B: ON/OFFi Gain selector

MAX / -3 dB /-6 dB / -12 dB

u Input selector button
LINE / BALANCED■ Rear Panelo Line inputs

A-36 for right channel

To left channel input

L

Preamplifier

HIGH− ＋ − ＋To left channel input

RLOW!0 Balanced inputs② Inverted ( – ) ③ Non-inverted (＋)(Can be changed with phase selectorswitch !3)!2 Operation mode

selector
DUAL MONO /NORMAL / BRIDGE!1 Right/left-channel speaker
output terminals
A / B, two sets

!3 Balanced input phase selector switch !4 AC power supply
connector ★

Remarks
This product is available in versions for 120/220/230 V AC. Make sure that the voltage shown on the rear panel matches the AC line voltage in your area.
230 V version has an Eco Mode that switches power off after 120 minutes of inactivity.
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

The specifications and appearance of this product are subject to change without notice.
F1405Y PRINTED IN JAPAN 850-2187-00（B1）