ESL Virtuoso MK II

In 2012, Soltanus Acoustics unveiled the world’s first multi-panel electrostatic loudspeaker without an integrated crossover system: the ESL Virtuoso.

In the pursuit of the most natural and lifelike sound, we identified the crossover as a critical juncture in the signal path—one that can subtly, yet perceptibly, compromise clarity and coherence. Standard crossovers, even when meticulously engineered, introduce distortions and inconsistencies, amplified further by variations in component characteristics from different manufacturers.

Our solution was elegantly simple in concept, yet formidable in execution: eliminate the crossover entirely. Achieving this required years of dedicated research and development to engineer a fully unified panel-frame-transformer system. The result is a loudspeaker that delivers extraordinary clarity, speed, and precision, with a natural, uncolored sound and remarkably low distortion—capturing music with the authenticity and immediacy of a live performance.

Electrostatic loudspeakers are renowned for their capacitive nature, which results in exceptionally low impedance at high frequencies. The first generation of the ESL Virtuoso was no exception, with an impedance dipping to 1.5 Ω at 20 kHz—posing a challenge for amplifier selection.

To ensure seamless compatibility for even the most discerning tube amplifier owners, we undertook extensive, in-depth research into the underlying science of electrostatic loudspeakers. The outcome was a design that allows every amplifier, regardless of topology, to drive the ESL Virtuoso with absolute authority, preserving purity, dynamics, and tonal integrity.

Refining the ESL Virtuoso: Addressing the Core Challenges

To elevate the performance of our electrostatic loudspeakers, we identified two primary areas for improvement. First, the capacitance of the mid-tweeter panel needed to be reduced. We engineered a new panel with four times lower capacitance, constructed from precision wires instead of perforated steel plates. This design significantly increases the open area, allowing effortless, turbulence-free airflow, while the wires’ superior aerodynamic profile ensures exceptionally clean operation.

Additionally, these panels incorporate Mylar foil half the thickness of previous generations, extending the high-frequency response well beyond 40 kHz for unparalleled clarity and detail.

To complement the panels, we developed a dual-transformer architecture while maintaining a crossover system. A larger transformer drives the bass panels for authoritative low-frequency response, while a dedicated, smaller transformer powers the mid-tweeter panels, engineered with ultra-low parasitic capacitance to preserve transient precision and sonic purity.

These meticulous modifications yielded remarkable improvements:

High-Frequency Impedance

Quadrupled to 6.3 Ω at 20 kHz (with Brilliance Control at position 1), ensuring effortless amplifier compatibility and pristine treble clarity.

Low-Frequency Impedance

Quadrupled to 13 Ω at 20 Hz, improving control over subsonic content from LP records.

Extended High-Frequency Response

Raised from 20 kHz to 40 kHz, revealing micro-detail and shimmer previously unattainable.

Enhanced Low-Frequency Response

Extended downward from 40 Hz to 35 Hz for richer, more natural bass.

Brilliance Control

Added for subtle fine-tuning of the upper-frequency spectrum, adapting the presentation to your amplifier and personal preference.

Midrange Control

Allows precise adjustment of the mid-frequency content in three 3 dB increments, enabling optimal tonal balance and enhanced musical clarity.

Tonal Versatility

With the combination of brilliance, tweeter bias and midrange controls, the system offers 72 distinct tonal configurations, allowing you to perfectly tailor the frequency response to your room’s acoustics, amplifier characteristics, and personal listening preferences.

Refined Back Panel

The back panel was elegantly simplified: only two direct-input binding posts remain. The tweeter panel bias control is now more precise, and thanks to the higher impedance, the previous damping-factor correction circuit is no longer required. The addition of the Brilliance Control completes the system, offering bespoke tonal adjustment for the ultimate personalized listening experience.

Conclusion

The Soltanus Acoustics ESL Virtuoso MK II sets a new standard in electrostatic loudspeaker performance:

Exceptional high-frequency resolution
Deep, extended low-frequency response
Freedom in amplifier selection, requiring no high damping factor or high-current units
Enhanced tonal customization through fine-tuning options

In essence, the Virtuoso MK II allows you to fully enjoy your tube amplifiers and achieve a listening experience tailored precisely to your system and room.

Specifications

Frequency Response

35–40,000 Hz

Horizontal Dispersion

35°

Vertical Dispersion

150 cm Line Source

High-Frequency Transducer

120 × 14 cm Electrostatic Panel (200–40,000 Hz)

Low-Frequency Transducer

2 × 140 × 16 cm Dipole Electrostatic Panels per speaker

Sensitivity

Equivalent to 87 dB / 2.83 V at 4 meters

Impedance

8 Ω (minimum 6.3 Ω at 20 kHz)

Recommended Amplifier Power

20–100 W per channel

Maximum Input Voltage

35 V RMS

Maximum Sound Pressure Level

100 dB

Crossover Components

None (full-range, panel-frame-transformer unity)

Inputs

Custom Binding Posts

Weight

28 kg

Dimensions

153 × 68 × 5/33 cm