Handmade to Deliver Music with Full-Spectrum Dynamics and Heart-Palpitating Vibrancy: Japan-Built Esoteric S-03 Power Amplifier Features Linear 2x2 Dual-Mono Power Supply and LAPT Transistors
Piece by piece. By the delicate hands of specialists schooled in perfectionist-minded engineering. That is how each Esoteric S-03 power amplifier is assembled in Tokyo – because some things are too important to leave to soulless robots and mechanized processes. Yes, such mastery costs, but what price can you place on a component that creates seemingly endless vistas of spaciousness and enough power to drive loudspeakers to their wildest potential, delivering music with full-spectrum dynamics and heart-palpitating vibrancy at any volume? S-03 takes you there. And how.
Inspired by the flagship Grandiose M1, S-03 seeks to faithfully replicate every nuance in the audio signal. Nominally rated at 145Wpc into eight ohms and able to provide a mammoth 580Wpc into two ohms, S-03 relies on a superbly linear 2x2 dual-mono power supply distinguished by the separation of the left and right channels of both the front and drive stages into four independent sections. The dual-mono topology extends from the secondary windings of the transformers to the rectifier circuit, leading to extraordinary channel separation on par with reference-setting monoblock amplifiers.
S-03's large-capacity, El-type, 940VA power transformer is equally remarkable. Featuring separate windings on the left and right channels, a 5mm-thick steel base plate mount, three parallel 4,700 F capacitors per channel, heavy-duty cable wiring, it affords the type of full-bodied bass and tight, fast responsiveness that make songs, symphonies, and the like come alive with head-turning realism.
Esoteric also loaded S-03 with discrete balanced input buffer amplifiers, nine bus bars for each channel, bipolar LAPT transistors that boast an instantaneous peak capacity of 34A, a three-stage Darlington circuit with five parallel push-pull sections, and a unique LIDSC (Low Impedance Drive Stage Coupling) circuit to further enhance drive capability. All these decisions matter – you can read more on the technology below – but the upshot is that the only thing you need worry about is how to allocate more hours of listening time from your day. 100% Music Direct Guaranteed.
2x2 Dual Mono Power Supply Provides Stereo Output with Monoblock Thinking
The main feature differentiating monoblock and stereo amplifiers is the configuration of power supplies. In conventional stereo amplifier designs, one power supply is shared by both channels, since space and efficiency limitations preclude a dual-mono configuration. Starting with the flagship Grandioso models, Esoteric's stereo power amplifiers have featured a unique 2x2 dual-mono power supply that separates the left and right channels of the front and drive stages into four independent dual mono sections. By isolating the power supplies for the front (voltage amplification) stage, which handles weaker input signal, from those for the drive (current amplification) stage, which much contend with huge current fluctuations, S-03 effectively realizes more clearly focused details and breathtaking dynamics. Moreover, by optimizing the independent dual mono configuration-from the secondary windings of the transformers to the rectifier circuit, S-03 is also able to achieve clear channel separation on par with the finest monoblock amplifiers.
The Heart of S-03: Large-Capacity Custom Power Transformer
Class-leading 2x2 dual-mono power supplies are only capable of revealing their true worth by way of the investment of enormous resources. A robust power supply is critical to an amplifier's ability to deliver high power in a linear manner, is especially for the power transformer. Particular attention was paid to material selection, core size and even the mounting of S-03's custom-made EI-type power transformer. It was selected for the full-bodied, high-quality bass it provides. To preserve sound purity, the large-core 940VA transformer features separate windings for left and right channels, and is securely mounted on a rigid, 5mm-thick steel base plate. Three parallel 4,700 F capacitors per channel shorten charge and discharge times and provide a tighter, faster sound. Power supply wiring uses heavy-duty cables fitted with crimp terminals, which are tightly bolted together to reduce impedance to the lowest levels possible.
Breathtaking Speaker-Driving Power Ensures Accurate Damping for Large Woofers
Optimizing the S-03's loudspeaker drive capability required reducing the output impedance to an absolute minimum. To achieve this, a total of nine bus bars are used for each channel, while the output coil was eliminated. Strenuous efforts were made to simplify the circuit design and widen its range, resulting in an exceptional damping factor of 1,000 – considered a guideline for woofer drive capability. Even large-diameter woofers are provided with accurate damping for precise sound reproduction, giving an expansive feel across a wide range that reaches to the lowest frequencies.
Balanced Input Stage Configuration Enables High-Clarity Signal Amplification
S-03's audio input signal enters through discrete balanced input buffer amplifiers and is relayed to the amplification stage by way of a balanced low-impedance signal path. An outstanding dynamic range is assured by clean, noise-free signal amplification that provides the fine sensitivity needed to reproduce nuanced gradations between musical crescendos and silence.
Large Bipolar LAPT Transistors Deliver 34A of Instantaneous Output Current
S-03's large bipolar LAPT transistors are twice the size of more commonly used power transistors. They also boast an exceptional continuous current capacity of 17 amps and an instantaneous peak capacity of 34 amps. In addition, they offer superior high-frequency characteristics that contribute to accurate reproduction of subtle tonal qualities.
Three-Stage Darlington Circuit with Five Parallel Push-Pull Configuration
The power amplifier module uses bipolar LAPT transistors in a three-stage Darlington configuration with five parallel push-pull sections. To realize the superior high-frequency characteristics of these devices, a simplified amplifier circuit was developed to reduce the number of components and parallel elements.
LIDSC (Low Impedance Drive Stage Coupling) for Stellar Drive Capability
S-03's unique LIDSC circuit reduces the drive section's second stage to final stage output impedance while enhancing current supply capability. This makes it possible to maximize amplitude within the available power supply voltage while reducing distortion and give S-03 a loudspeaker drive capability approaching that of Esoteric's Monoblock M1.