Esoteric C03X


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The C03X preamplifier as the embodiment of ESOTERIC technologies, enriches the musical experience of your system to a dramatic extent.

Alt Text C03X

How far can a high quality preamplifier evolve the musical experience of a system?

The ESOTERIC’s C03X is indeed a definitive starting point when considering an answer to the proposition.

This brand new full balance dual-mono preamplifier brings out fantastic sonic impressions with seamless, stress-free beautiful sounds.

This comes as a fruitful result of ESOTERIC’s analog audio technologies accumulated over many years of dedicated research.

Here is the newest preamplifier in ESOTERIC’s “Master Sound Works” series.

Their new 3D optimised chassis features a four compartment structure.

Each circuit block is housed in its own compartment so as to place them three dimensionally.

This structure greatly contributes to reducing mutual interference between circuits and provides the shortest signal path.

Thick aluminum is used for the exterior.

The 5mm-thick steel bottom chassis is supported at four points using ESOTERIC’s proprietary ‘Pinpoint Foot’ (patent number: JP4075477).

Vibrations have been suppressed effectively and high rigidity has been achieved.

Adding the C03X to the system will provide an aesthetic integrity to the system. The front, top and side panels along with the front corners are made of thick aluminum.

The rounded shape of the top panel and the corners, where there are no screws at all, are inherited designs from the separate component system of the ESOTERIC flagship line.

The dual-mono design enables the C03X to have a power source and a power transformer for each of the right and left channels.

This was done in order to eliminate mutual interference between the channels and to prevent noise being introduced from the power line. Pure and clean amplification is the great outcome.

A Fully-Balanced Configuration Gives an Excellent S/N Ratio C03X


Signals are received through the fully-balanced input buffer amplifier design for an individual input system and maintains this balanced transmission at low impedance, so that all inputs can remain free from common mode noise.

This fully-balanced configuration increases the purity of signal transmission and provides an absolutely excellent audio S/N ratio.


ESOTERIC-QVCS (*) is a volume control system, which takes full advantage of unit’s pure signal paths.

By turning the volume knob, the gain variable volume of all the four circuits – right and left channels, positive and negative powers – are activated.

In this way, this system keeps audio signals independent (from right to left and from positive to negative), so that sounds are reproduced clearly with good channel separation and accurate phase characteristics.

Furthermore, the deletion of cabling from the audio board to the volume device radically shortens the audio signal path and minimizes sound deterioration.

As a result, the C03X can now reproduce sounds that are perfectly suitable for a high-end preamplifier.

QVCS: Quad Volume Control System

 Low Noise Operation

The control board for the entire ESOTERIC-QVCS is physically separated from the audio circuit and also electrically isolated using a photo coupler. The circuit design has also taken measures to make sure that microcomputer noise is not introduced into the audio path. This is accomplished by disabling the microcomputer until a function is initiated.

Low Impedance, High Response Power Circuit (Three Transformers)

Three different transformers for the three different power sources – the audio circuits of both the right and the left channels along with the control section – combined with large capacitors make this extremely clean low impedance and high response power circuit possible.


ESOTERIC’s Own Output Buffer Circuit with Fortified Current Transmission Enhances the Driving Performance of the Power Amplifier


Looking at the subtleties of the signal transmission between preamplifier and power amplifier, the ability of the component to transfer current efficiently determines the overall quality of the system.

The pre-amplifier plays a significant role in this relationship. Serving as a line driver, it should fully drive the power amplifier to its maximum level to thoroughly convey music signals that can include such a broad range of music expression, from pianissimo to fortissimo.

What is required here is high performance via high speed current transmission.

For the purpose of attaining the ultimate performance of the C-03X as a line driver, the output buffer amplifier circuit uses high quality materials and has its own board separate from the input stage.

The output buffer circuit provides the high performance necessary. Its slew rate, representing response speeds of 2,000 V/microsecond – is incredibly fast.

Since this buffer circuit is provided to each RCA output terminal and to the hot and the cold pins of the XLR output, the instant current supplied gets maximized.

The C03X re-enacts the breathtaking reality of music, whose dynamism tended to disappear in older systems during smaller current transmissions between the preamplifier and a power amplifier.

*HCLD: High Current-capacity Line Driver

Extraordinary Usability

Gain per input is widely adjustable with a precision of +/-18 dB = 0.5 dB per step. This reduces volume variations from source to source.

Volume balance between the right and left channels is adjustable with a precision of +/-6 dB = 0.5 dB per step.

The output phase invert function allows an output that is appropriate for the power amplifier used. In addition, it is possible to individually determine a source-specific output phase and to easily implement phase management for the system.

Unbalanced output (RCA), balanced output (XLR) and RCA + XLR simultaneous output are the options.

RCA-2 terminals are provided to switch between normal line output and AV through output. This function allows you to connect AV preamp, sharing the same front two-channel speakers (and its dedicated amplification system) between music and surround movie applications.

Source equipment names can be programmed into the system using the remote controller.

Display dimmer, mute, auto-display-off functions are also available.

Specifications C03X

Connectors RCA x 3 pairs (RCA 2 can be used as an AV pre-input )

XLR x 2 pairs

Input impedance LINE : 10 kOhms
Input sensitvity At rated output : 510 mV

At 800 mV output : 200 mV

Maximum input level 12 V
Connectors RCA x 2 pairs

XLR x 2 pairs

Output impedance RCA: 47 Ohms

XLR: 100 Ohms

Maximum output level 7.5 V ( RCA output, 1kHz, 0.003%)

15V ( XLR output, 1kHz, 0.003%)

Frequency response 1Hz – 200 kHz ( -3 dB )

3Hz – 50 kHz (-0.2 dB)

S/N ratio 116 dB ( 2 V input, A-weight )
Total harmonic distortion 0.0006% (RCA)

0.0004% ( XLR)

Gain +12 dB
Rated output 2 V
Power supply AC 230V, 50Hz ; AC 120V, 60Hz ; AC 220V, 60Hz
Power consumption 18W
External dimensions

(W x H x D, including protrusions)

445 x 131 x 378 mm

(17 5/8˝ x 5 1/4˝ x 15˝ )

Weight 22 kg ( 48 5/8 lb)
 Power cord set x 1; Remote control (RC-1156) x 1; Batteries for remote control (AA) x 2; Felts x3; Owner’s manual x 1; Warranty card x 1




Pride and Mission of "ESOTERIC" They are to reproduce the Original Master Sound,

"The joy of the highest levels of musical elation." Their corporate philosophy, as their foundation, has been unremittingly developing excellent audio products to reproduce the original sound performed by musicians in studio or concert hall. Since the inception of TEAC corporation in 1953, audio equipment has gone through various phases of development. From analogue vinyl records to analogue tapes, CDs to Super Audio CDs in digital era, then streaming audio in nowadays, there have been undergoing several transitions and technical innovations in auditory media. ESOTERIC COMPANY, which was born in the midst of such transition, shall pursue a unique path as a high-end audio brand, by deploying Super Audio CD players equipped with the VRDS mechanism that has sublimated its original mechatronics technology, as well as D/A converters, network players, amplifiers, and clock generators. Despite changing times and whirlwind markets, there remain musical connoisseurs who are seeking true excitement. As long as there are such people, we shall with great care, develop and actively release new products, that improve upon the "state of the art," within each business category that we pursue. We believe this is our mission