The history of Accuphase’s class A integrated amplifier
has been started since E-530 was born in 2002.
In 2013, Accuphase launched E-600 as the flagship ofintegrated amplifier which was installed AAVA volumesystem . E-650 is the 5 generation of E-600 series.
thTechnical highlights are “Ultra low noise” and “Super
high Damping Factor”.
E-650 features “Balanced AAVA” to realize thosefeatures and transfer the ideal audio signal from the input
to the output.
It is inherited from our flagship pre-amplifier C-3850 andpower amplifier A-250.

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The dimensions are the same but the weight is slightly
heavier than E-600 ( E-600: 24.7kg).

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The design principle follows the Accuphase 40th
anniversary models .
The carve around the display emphasizes dignified andimpressive design and the enlarged LED bar graphbrings very clear visibility.
Two pairs of large speaker terminals are equipped on therear panel.
You can choose different loudspeakers whichever theywant to listen to.
Both A+B channels can be selected as well for bi-wiring
connection.

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E-650 takes the mono block construction. Large powertransformer and capacitors are positioned between L andR channel separated the power amplifier blocks.
Custom-made volume sensor mechanism which has
distinguished operation feeling and ultimate reliability isalso installed.
Balanced AAVA circuit block is located near by the frontpanel.

4The capacity of main capacitors are drastically increased
to 50000uFx2 .
This capacitors is developed for only E-650 and it
contributes to the extreme sound performance.

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The rated output power of E-650 is 30W into 8 Ω load,
60W into 4 Ω load and 120W into 2Ω load. The actualmaximum output power achieves 190W into 2Ω load.
Especially, the rated output power into 2 Ω load isenhanced 19% from the former model E-600 by theimprovement of the power supply and the power
amplifier circuit.

6E-650 is the remarkable low noise amplifier exceeding E600.
E-650 marks 80µV of the actual noise voltage.
This is 33% lower(-3.5dB) than the former model E-600.
E-650 guarantees 102dB Signal to Noise ratio at themaximum gain.

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The AAVA(Accuphase Analog Vari-gain Amplifier) is a
volume control principle that eliminates all variable
resistors from the signal path. It is totally different fromany others.
E-650 employs two AAVA modules per channel with afully balanced configuration from the input to the output.
Tone control system which is the post stage of AAVA
works as balanced AAVA circuit as well.
The power amplifier part can receive those positive andnegative signals at the same time by the instrumentation
amplifier.
It works as the totally balanced circuit which is tolerant tointernal and external harmful noise.
“Balanced AAVA” volume control system was originallydesigned only for Accuphase flagship pre-amplifiers, C3800 and C-3850. Our engineering team succeeded ininstalling this unique technology into the integrated
amplifier as well.
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E-650 achieves 800 of Damping-Factor.
It is 60% higher than the former model E-600.
800 of DF is the guaranteed spec. In fact, DF of E-650
achieves 1200.
*Damping-Factor, DF:
An index of speaker driving ability. Higher DampingFactor amplifier has higher speaker driving ability.
DF = 8 ohm / Output-impedance

9Remote-sensing is a technique to make lower output
impedance of the amplifier by negative feedback withsignal sensing from close up speaker terminals.
Balanced Remote-sensing is also make impedance evenlower by GND sensing and the negative feedback ofGND level with adding the signal sensing.
Not only Damping-factor is improved but also Total
Harmonic Distortion and Intermodulation Distortion getbetter by Balanced Remote-sensing.

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Although a mechanical relay is the most popular
component for speaker protection, it does not have highreliability and low contact resistance either.
E-650 applies a MOS-FET switch instead of mechanicalrelay for speaker protection.
Damping-Factor, reliability and sound quality are all
improved by MOS-FET switch. We adopted a new MOSFET which has very low on resistance of 1.6mΩ. (E-600
used 2.6mΩ on resistance MOS-FET)
By connecting speaker terminals and PC-board directly,
signal path can be made shorter to obtain the low
impedance.

11E-650 equipped with a high performance headphone
amplifier which is designed by using fully discreteconfiguration.
It brings less-than-half the noise and 2 times higher
output power than those of E-600.
E-650 drives any kinds of headphones easily andperforms your music with the best sound quality.

12E-650 accepts the digital input board DAC-50 and analog
input board AD-50.
You can see the figure of sampling frequency input ofDAC-50 on the display and can choose any preferred
input sources with the selector on the front panel.

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