The Importance of the Preamp Section and Its Power Supply in an Integrated Amplifier

In general, integrated amplifiers select inputs in the internal preamp stage, adjust the volume, and send the signal to the power amplifier block to drive the speakers. The power amplifier blocks of the F-01/F-02 amplify the signal from the preamp to a level approximately 27 times higher. In an audio system, the sound quality of the preamp has a significant effect on the quality of the entire system because of this high gain ratio. By isolating the preamp section's power supply from other circuits to prevent mutual interference, and by increasing its capacitance, the integrated amplifier can deliver higher quality sound to the speakers that can match the quality of a high-end separate amplifier system.

The Original F-01/F-02 Preamp Design

The preamp section of the F-01/F-02 is meticulously designed as a high-end model, with a large, fully balanced dual-mono circuit configuration and the “Ultra Fidelity Attenuator System” developed for the Grandioso C1X. The preamp power rectification circuit of the F-01/F-02 is separated from the main power transformer (EI core 940VA) winding exclusively for the preamp circuit, and the rectification circuits are designed independently for each audio and logic control circuit to prevent noise contamination. The audio rectification circuit uses high-capacitance Grandioso custom capacitors in a parallel configuration (4,700µF ×4). Current can be charged/discharged to multiple capacitors at different times, ensuring a stable and clean power supply to the preamp at all times.

External Power Supply Designed Exclusively for Audio Circuits in the Preamp Section

PS-01F is an external power supply designed exclusively for the audio circuit of the F-01/F-02 preamp section.
It is important that the preamp section, which handles small signals, and the power amplifier section, which sends large currents to the speakers, are not affected by each other. By adding the PS-01F to the F-01/F-02, the preamp’s capacitance is greatly increased and clearly separated from the amplifier’s main rectifier, allowing the user to enjoy the finest details and dynamics of music, reminiscent of the Grandioso C1X, our flagship preamp with a separate power supply.

Power Supply Configuration

PS-01F increases the capacitance of the preamplifier and improves the left/right channel independence of the rectifier.

Power Supply Configuration

PS-01F increases the capacitance of the preamplifier and improves the left/right channel independence of the rectifier.

Equipped With a Large Toroidal Core Transformer

The PS-01F is equipped with a large 200VA power transformer. The large transformer, which has approximately 10 times the capacity required for a preamp audio circuit, makes the PS-01F extremely responsive to dynamic changes in the power supply, enabling dynamic reproduction of musical inflections.

High Capacitance Rectifier

By connecting the PS-01F to the F-01/F-02, the capacitance of the power rectifier in the preamp section is significantly increased from a total of 18,800μF to 27,200μF ×2, resulting in an even richer sound with excellent channel separation.

Mechanical Construction for High Sound Performance

The rigid, heavy-duty, thick aluminum panel enclosure and Esoteric’s unique Pinpoint Isolation Feet (patents #4075477 and #3778108), which integrate the spike and mounting plate, effectively reduce unwanted vibration that affects sound quality. The three isolation feet are positioned for optimum sound quality after repeated listening tests. The top of the isolation feet is held in place by the weight of the chassis when installed. By avoiding the stress concentration caused by screwing the feet into the large surface area of the lower chassis, a more open sound is created. The bottom chassis is laser-slotted to provide optimum vibration damping for each circuit component inside the chassis.

Semi Floating Top Panel

The enclosure’s top panel utilizes a screwless semi-floating structure that further contributes to an open and dynamic sound.

High Quality DC Cable Included

A DC cable (1.5 m / 1 piece) with a highly reliable, large die-cast aluminum connector is included.