System Synergy - Digital 01

Preamplifier: Vitus Audio SL-103

RRP £32,800

The ideal partner for the SM-103 Mk.II power amplifiers, the SL-103 is a true balanced, Class A linestage preamplifier that earned The Absolute Sound’s 2025 Preamplifier of the Year award. It shares the same Signature Series lineage that traces back to the original SL-100, launched at CES in 2004, but benefits from fundamental innovations developed during the creation of Vitus’s multi-chassis Masterpiece Series.

The SL-103 uses matched transistors and super-precision resistors in brand new circuitry, with a relay-controlled fixed-resistor volume network imported directly from the Masterpiece Series MP-L201. This provides 0.5dB-per-step resolution across a range from -90dB to +18dB, ensuring precise and transparent volume control at any listening level. Five inputs (three XLR balanced, two RCA) and multiple outputs provide comprehensive system connectivity. The true balanced design, combined with multiple levels of power supply regulation, achieves an ultra-low noise floor that allows the finest musical details to emerge from silence.

Jonathan Valin described the Vitus Signature Series electronics as “the best Class A solid-state gear I’ve heard in my system, and at $40,000 for the preamp and $75,000 the pair for the monoblock amplifiers, extraordinary bargains in the cost-unlimited world of ultra-high-end electronics.” In this system, the SL-103 serves as the command centre, ensuring that the extraordinary signal from the Kalista DreamPlay XC reaches the SM-103 power amplifiers with absolute fidelity.

Grounding: Entreq Pluton Ground Box

RRP £7,000

In a system of this calibre, the electrical environment in which the components operate becomes critically important. The Entreq Pluton is a flagship grounding solution from the Swedish specialists, designed to drain high-frequency noise and stray voltages from your system’s signal path, providing a clean, stable ground reference that the mains supply alone cannot deliver.
The Pluton is effectively three of Entreq’s Olympus Infinity Tungsten ground boxes housed within a single, purpose-built oak enclosure using Entreq’s constrained-layer construction. At 35kg, it is a substantial piece of equipment. Six pure solid silver binding posts provide three independent grounding zones, offering the flexibility to ground the negative speaker terminals of both monaural amplifiers while simultaneously grounding the preamplifier and source — or any other configuration that best suits the system.
The internal mineral and tungsten mixture is specifically formulated to present an attractive ground path for the high-frequency noise currents that circulate through audio systems, offering them a point of dissipation rather than allowing them to flow through the signal path. The effect on a system of this resolution is not subtle: a lower noise floor, improved dynamic range, greater spatial definition and a more natural, relaxed musical flow. The Pluton is best paired with Entreq’s Eartha Olympus grounding cables for maximum performance.

Acoustic Treatment: Acustica Applicata Volcano Variable Resonator

RRP £2,100

At this level of system performance, the listening room itself becomes a critical component. The Acustica Applicata Volcano is a variable Helmholtz resonator — developed and manufactured exclusively in Italy — designed to address the acoustic resonances and complex energy turbulences that exist in any domestic listening space, particularly in the area between and around the loudspeakers where the energy fields from both channels collide.

Standing 105cm tall with a 38cm diameter, the Volcano is constructed from transparent Plexiglas with wooden end caps, giving it a distinctive sculptural presence. Its most important feature is tunability: an internal cylinder can be adjusted to precisely match the resonant frequency of your room, optimising the depth and speed of low-frequency reproduction. In its standard configuration it is effective down to 35Hz, with an optional additional module extending this to 25Hz. The two-part construction is modular and requires no gluing or fixing.

Positioned between the loudspeakers — where sound pressure from both channels creates the most complex interference patterns — the Volcano selectively absorbs unwanted resonances while returning energy to depressed frequencies. The audible result is a clear improvement in bass impact and definition, significantly enhanced three-dimensional imaging, improved tonal balance and, most strikingly, a dramatic increase in dynamic contrast. In a system built around the Avalon ISIS Signature’s extraordinary resolving power, the Volcano ensures that the listening room supports rather than undermines the performance.

Cables: Entreq Olympus Cables

RRP from £10,000

Entreq’s Olympus cable range represents the summit of the Swedish company’s approach to signal transmission — an approach rooted in the same philosophy that drives their grounding products: the removal of noise and interference from the signal path, rather than the addition of any particular sonic character.

The Olympus range spans interconnects, speaker cables and power cables, each designed using Entreq’s proprietary conductor geometries and natural materials. A key feature of Entreq’s cable design is the integration of grounding capability: when used in conjunction with an Entreq ground box such as the Pluton, the cables can drain noise directly from the signal path, creating a synergy between cable and grounding system that yields results greater than either component achieves alone.

In this system, Entreq Olympus cables connect every component — from source to preamplifier, preamplifier to power amplifiers, and amplifiers to loudspeakers — ensuring a consistent, coherent signal path throughout. The result is a presentation characterised by an exceptionally low noise floor, natural tonal balance, and a sense of musical flow and ease that allows the extraordinary capabilities of the Kalista, Vitus and Avalon components to be heard without any cable-imposed limitation.