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A-80
A-80 Monaural Power Amplifier
Introduction
Introduction
Features
Features
Specications
Specications
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Gallery
Master Sound Works・・・Mono-block amplification recreates the master tape experience!

  • Stereo "Best Buy Component 2012"

The ultimate challenge: "reproduce every drop of recorded material that lives and breathes within the master tape."

For over twenty years, ESOTERIC has drawn on TEAC's extensive heritage in audio reproduction to forge state of the art sound technologies. These efforts have now come to fruition in ESOTERIC's Master Sound Works product category.
The design of the A-80 mono-block power amplifier is focused on one thing-the re-creation of a masterpiece.

The A-80's power supply, housing and circuitry, with a superior 1kVA toroidal transformer, exemplify this uncompromising design.
The A-80's spectacular sound quality reproduces richly blended symphonies and soundtracks, the passion of the musicians, the atmosphere of the concert hall, and the true to life experience of any known acoustic venue.

1kVA high-capacity toroidal transformer
The explosive sound delivered by the A-80 made this power capacity a prerequisite.

high-capacity toroidal transformer ESOTERIC began by thoroughly enhancing the power supply used for Master Sound Works power amplifiers. A-80's main transformer is a powerful 1kVA high-capacity toroidal transformer that supplies loudspeakers with a dramatically increased level of power. This highly efficient transformer provides, in addition to low noise and low distortion, enough power to instantaneously follow every nuance of a sound signal.

The A-80 employs a dual transformer structure which incorporates an R Core Transformer as its sub-transformer. With no voltage fluctuations in the circuit design even at high power, the A-80 eliminates the need for a constant-voltage circuit within the amplifier stage. This purifies the power line, obtaining a more expansive and detailed sound quality.

Two large 33,000 μF smoothing electrolytic capacitors, with low etching magnification for electrode aluminum foil, give the A-80 more than enough headroom capacity. By placing the amplifier stages and control circuits on the upper side of a 9 mm thick steel plate dividing the housing, and the power supply including the transformers on the lower side, ESOTERIC has been able to prevent noise interference between the circuits at rectification, improving S/N measurement and in actual listening. We used a Schottky barrier diode for rectification in each circuit helping to refine the soundstage. By eliminating noise from the circuit principally in recovery phase, we've achieved acoustic reproduction with an extremely high quality and purity.

Wide range, high speed, and high drivability with an amplifier circuit design to achieve the highest quality in acoustic reproduction

A-80 circuit

A circuit that is focused solely on sound quality is one of the A-80's outstanding features. The amplifier's two-stage Darlington configuration provides current amplification that will drive any type of speakers without compromise. With a three-step parallel push pull system for the output stage, the A-80's breaking ability and refinement is further enhanced.

The voltage amplifier consists of a differential amplifier circuit with Cascode connections for the first stage, and a grounded-emitter amplifier circuit with Darlington connections for the second stage. Both are supplied with high idling current and are designed for extremely high speed and wide band capability. Furthermore, by applying an up/down symmetric push pull action at all stages, the A-80 is able to achieve straight forward clip character and stable drive at the high current amplifier stage.

High grade parts without compromise. A prerequisite for exceptional sound quality.

A-80 ESOTERIC's original RCA input terminal

Every component of an ESOTERIC amplifier is selected from a high-end perspective and is carefully chosen based on its attributes and exhaustive listening tests. ESOTERIC's original RCA input terminal boasts high reliability and contact performance, while the speaker terminals incorporate pure copper and gold plating in the core of WBT's nextgen: WBT-0710Cu conductor. This implementation achieves high conductivity and low resistance boosting overall signal purity. Furthermore, the A-80's metal-film resistor, high frequency low impedance electrolytic capacitor, and output transistors are all of the very highest quality. With this uncompromising attitude to overall system quality, we have extracted pure amplifier performance that minimizes the loss of signal information and maximizes transmission capability.

Unique chassis structure integrating accuracy & vibration control

Unique chassis structure

All of the A-80's structures are fixed to a precisely engineered main chassis of 9 mm steel plate. The amplifier's pin-point feet are directly connected to the chassis for mechanical grounding. Suspending the transformer and capacitor on the lower part of the main chassis and locating the substrate on the upper part eliminates leakage of magnetic flux and shields the components from the influence of vibration.

Like the A-80's state of the art chassis, the outer housing is also worked to the highest level of precision at our machining center. Such precision allows a massive reduction in the difference in vibration levels between amplifiers when two or more A-80s are used together.

Unique pin-point foot to support the housing

Steel pins of 30 mm diameter are directly connected to the 9 mm steel plate that forms the A-80's base providing a three-point mount. This design disperses vibrations generated by the transformer, capacitor, etc., while simultaneously eliminating negative effects caused by vibrations due to acoustic pressure from loudspeakers or other external influences.

All of the A-80's panels-including the 20 mm thick front panel are formed from precision-worked aluminum alloy.

The front and the sides are firmly attached using a three-board splice technique used for high grade furniture. With this structure, the housing limits unnecessary vibrations as much as possible.

Large vibration free heat sink with 10 mm thick base

Large vibration free heat sink

Each heat-sink fin is supported by a 4 mm diameter stainless steel pin limiting any noise influence that may generate from the fins.

Audio features Maximum useful output power 200W (8ohms)
400W (4ohms)
Frequency response 10Hz to 100kHz (1W, 8ohms, +0/-3dB)
Signal-to-noise ratio more than 110dB (Awgt)
Total harmonic distortion 0.05% (1kHz, 160W, 20kHz LPF)
Input sensitivity 850mVrms/160W (8ohms)
Input impedance 200kohms (RCA)
General Power supply AC 230V 50Hz
AC 120V 60Hz
AC 220V 60Hz
Power consumption 200W
External dimensions (W×H×D) 250×219×430 mm
(9-7/8×8-5/8×17 ")
Weight 31kg (69lbs)
- Design and specifications are subject to change without notice.
- This product is available in three different power supply variations shown in the chart above. 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.

A-80 A-80 A-80
A-80

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