Class A Reference Model
Setting out to create one of the most desirable integrated amplifiers available, Esoteric brought together a fully balanced preamplifier and a Class-A power amplifier-both directly derived from its well-respected Grandioso line-to created a new reference for integrated amplifiers that gives full expression to the smooth, full-bodied tones and delicately shaded textures of your favorite music. Featuring distinctive dual monaural construction that extends through all stages, from preamplifier inputs through to the final stage of its power amplifier output, the Esoteric F-03A Integrated Amplifier brings out the full audio potential of Esoteric’s highly regarded K and N Series of digital players.
F-Series Philosophy: Basic and Complete
Representing a new generation of integrated amplifiers, Esoteric’s new F Series has been  thoroughly invested with proven results gained in the development of our flagship Grandioso line of separate amplifiers. With the goal of capturing all the inherent warmth and texture of music, not only were the outstanding expressive powers of the Grandioso line pursued, the utmost limits of audio performance were also concentrated into an integrated configuration that offers excellent usability combined with an attractiveness that more than compensates for the limitations of their size. Basic and Complete. With sights set on creating a unique presence in the category, the Esoteric F Series is born.
A Fully Balanced Preamplifier
 One result of the lavish attention given to the development of the F Series is the preamplifier’s fully balanced configuration, which derives from our highly esteemed C Series preamplifier models. Impervious to noise, it delivers pure and powerful signal amplification at ultra-low impedance.
Dual Monaural by Design
 The one design feature of these amplifiers that most clearly reflects Grandioso thinking is their dual monaural configuration, which maintains complete left and right channel independence through all stages, from preamplifier to the power amplifier’s final stage. As Esoteric integrated amplifiers, the major investments made in circuit construction expertise and materials developed over the years yield excellent channel separation and a measure of sound quality that transcends the class.
ESOTERIC-QVCS
 Playing a significant role in the F Series’ balanced dual monaural configuration is the proprietary Quad Volume Control System (QVCS), which incorporates a total of four precision switched resistor ladder networks operating in unison to electronically and independently control the left and right channels and their positive and negative phases. This system helps maintain superb audio clarity, excellent channel separation and highly accurate phase characteristics. Further, by eliminating all volume control wiring on the audio board, the resulting shorter signal path minimizes deterioration of sound quality while realizing exceptionally low distortion.
* QVCS: Quad Volume Control System
Ultra-Low-Noise Logic Control
 As a countermeasure against noise, all control lines have been electronically separated from the main body of the preamplifier with the use of isolator elements integrated into the front panel.
High-Precision Ball Bearing Control Knobs
Employing the same high-precision bearing mechanisms used in our Grandioso components, the F Series’ volume control knobs and selector switches provide exceptionally smooth operation with an analog feel free of any mechanical play. Sparing no cost, all panel knobs are also custom-machined from solid aluminum.
 
Dual Mono Phonostage Preamp
 The dual mono phonostage preamp (MM/MC) features independent left and right channel power sources and independent circuits.
High-Quality Headphone Amplifier
 The powerful headphone amp provides abundant output to effectively drive even difficult to power high-end high-impedance headphones.
3-Band Tone Control (Treble/Middle/Bass)
 Commitment to achieving all the quality associated with high-end components results in a balanced dual monaural configuration consisting of four circuits (L/R, -/+) for each band. This system enables users to adjust tone settings free of any concerns about sound quality deterioration. Shifting the variable band more than usual toward the high and low frequency ranges (14kHz/63Hz) permits fine adjustment of bass and treble without adversely affecting the original source signal. Fully electronic control also permits fine adjustment of up to ±12dB in 0.5dB steps. The middle band can also be utilized as a loudness preset when set to the minus side and used in conjunction with the Tone Bypass switch.
Power Amplifier Input Stage Features Balanced Configuration
 The power amplification section’s front stage is balanced in line with the thinking behind our S Series separate amplifiers. Its low impedance and clean amplification further enhance the dynamic range.
Large-Capacity Custom Power Transformer – The Nucleus of the Finest Power Amplifiers
 The power supplies of the F Series feature large-core 940VA custom EI power transformers and 40,000µF block capacitors for each channel in a dual monaural configuration. Large-gauge cable is used in all connections to help minimize impedance. As in our separate power amplifiers, this outstanding power section achieves a theoretically linear power output ranging from 30W at an 8Ω load to 60W at 4Ω for faithful reproduction of every musical dynamic.
Low Impedance for Enhanced Drive Capability
 Utilizing eight 1mm-thick bus bars formed of high-purity OFC, the speaker output section employs MOSFET switching with no mechanical contacts. Coils have also been eliminated from the output stage to minimize impedance and enhance drive capability.