Features - Esoteric E-03 Mode D'emploi

A design concept based on a complete commitment
to quality
Built according to the separate-chassis implementation of our
high-end models, the E-03 is a phonostage preamplifier designed
to produce the optimum in sound quality from audio signals on
an analog record. Functionality has been purposely kept simple
while the number of circuits has been reduced. The design we
have used for high-quality sound technology is a dual monaural
configuration with separate power supplies and seperate audio
circuits.
Dual monaural configuration
The right and left channels are isolated onto separate circuit
boards. Similarly, each channel is equipped with its own power
supply and R-core power transformer. Since right and left channels
do not share these resources, the signal path and separation
characteristics are ideal and power supply capacity is exceptional.
A symmetrical interior layout adds to physical stability and reduces
noise.
Audio circuits
The audio circuits are built from discrete components only. The
amplifier circuit is composed of the moving coil (MC) head
amplifier, which amplifies the minute signal levels output by the
MC cartridge to the same level as a MM cartridge output, the RIAA
amplifier, which amplifies the signals to line output while
obtaining RIAA characteristics, and an output buffer amplifier. In
the MC head amplifier that handles minute signals, development
efforts were concentrated on preserving the purity of the audio
signal. Use of an NF-CR type RIAA amplifier has made it possible to
balance excellent RIAA characteristics with reduced NF (negative
feedback). A high-power supply voltage provides an amplification
factor of about 40 dB giving plenty of headroom. The output
buffer amplifier is also a high-voltage driver circuit that can transfer
a variety of audio signals to an external preamplifier with ease.

Features

Support for multiple cartridge types
Since we regarded support for the variety of MC cartridges
available essential, we have MC-compliant equipped two input
circuits with a wide range of load resistance (load impedance)
values. A 100 Ω or larger load resistance used to be the norm, but
MC cartridges with very low internal resistance are now common
and phonoamplifiers offering low-load resistance have become
possible. By contrast, the recommended load resistance for MM
cartridges is primarily 47 kΩ or 50 kΩ while the recommended
load capacity has a greater range. The MM mode of the INPUT #2
terminal makes it possible to adjust to a wide range of load
capacities.
A simple configuration
The E-03 design avoids the use of microprocessors to eliminate
microprocessor noise.
To optimize the signal path, relays handle all switching of inputs
and loads directly on to the audio circuit boards without routing
signals to the mechanical switches on the front panel.
The number of switching functions has been kept to a minimum
to reduce the number of circuits the audio signal has to go
through. This attention to detail is required in the development of
a phonostage preamplifier due to the delicate signals that they
must process.
Cabinet Construction
The two-part chassis design prevents leakage flux from the power
transformer from effecting the audio circuits and effectively
improves cabinet rigidity. Three pinpoint feet made of quenched
steel, a feature unique to Esoteric, help to ensure a vibration-free
structure.
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