C-03x Pre-Amplifier

    The Overview

    Reproduce the beautiful sounds of audio
    as accurately as they were recorded.
    The C-03X preamplifier as the embodiment
    of ESOTERIC technologies,
    enriches the musical experience of your system
    to a dramatic extent.

    How far can a high quality preamplifier evolve the musical experience of a system? The ESOTERIC's C-03X 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.

    Our new 3D optimized 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 C-03X 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 Features

Dual-Mono Designed for Right-Left Independence

 The dual-mono design enables the C-03X 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


 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 C-03X 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 by the user.

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 preamplifier plays a significant role in this relationship. Serving as a line driver, it should fully drives 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 C-03X reenacts 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 to the C-02, 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.
  • The Specs

    Speaker Outputs
    Rated output power STEREO 200 W + 200 W (8 Ω)
    400 W + 400 W (4 Ω)
    BTL BTL 800 W (8 Ω)
    Maximum output power STEREO 250 W + 250 W (8 Ω) (JEITA)
    500 W + 500 W (4 Ω) (JEITA)
    BTL 1,000 W (8 Ω) (JEITA)
    Frequency response 5 Hz ~ 100 kHz (1 W, 8 Ω, ±1 dB)
    Signal-to-noise ratio (S/N) 117 dB or more (JEITA)
    Total harmonic distortion 0.009 %
    (1 kHz, 8 Ω, Rated output power)
    Minimum required impedance STEREO 4 Ω / BTL 4 Ω
    Gain 28 dB
    Analog audio inputs
    Jacks RCA jacks 1 stereo
    XLR jacks 1 stereo
    Input impedance RCA 150 kΩ / XLR 320 kΩ
    Power supply AC 230V 50Hz
    AC 120V 60Hz
    AC 220V 60Hz
    Power consumption 550 W
    External dimensions (W x H x D) 445 x 220 x 430 mm
    (17 1/2" x 8 5/8" x 16 15/16" )
    (including protrusions)
    Weight 41.2 kg (91.5 lb)
    - 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.