Grandioso M1X

The Esoteric Grandioso M1X is a high-end power amplifier with a redesigned drive stage and power supply section. Its circuit architecture uses a simple, minimalist approach intended to preserve musical harmonics and low-level detail, while the chassis and high-current output section are designed to control vibration and speaker load.

The M1X is compatible with Esoteric’s ES-Link Analogue current transmission system, used with the Grandioso C1X linestage preamplifier. This connection method transmits approximately 100 times more current than conventional voltage transmission, reducing susceptibility to noise and sending the full energy of the music to the amplifier. It is also not affected in principle by the impedance of the interconnects between the preamplifier and amplifier, helping maintain the integrity of the signal from the preamplifier output to the amplifier input.

The newly developed drive stage has increased in size by 150%, moving from 6 to 12 parallels. It provides power linearity from 300W/8Ω to 2,400W/1Ω*, supplying current in response to changes in load level. This allows the amplifier to handle speakers with varying impedance characteristics while retaining wide dynamic range.

The main power supply transformer is rated at 3,000VA and weighs 19kg. It uses a heavier winding gauge to improve rectification capability. Esoteric custom capacitors provide a total capacity of 60,000μF, supporting the amplifier’s power supply and its tonal character. The power supply occupies approximately 60% of the M1X’s internal components.

A dedicated power supply unit serves the pre-drive stage, or voltage amplification stage, which handles the extremely low-level signal from the preamplifier. Separating this section from the drive stage reduces the effect of its large current fluctuations and improves resolution. Even during a full orchestral climax, the amplifier is designed to reproduce subtle detail from individual instruments.

All 24 transistors in the drive stage are controlled at the same temperature for balance and stability. The phase compensation circuit uses a simple single-pole configuration, allowing the final stage to operate without a coil. This circuit approach is intended to preserve the overtones that can be lost during amplification.

The drive stage uses large bus bars, extra-thick copper-clad printed circuit boards and ultra-heavy-gauge cables. A bolt-on connector system secures the cable connections and minimises loss. Lower internal impedance supports control of large-diameter woofers and extends the amplifier’s low-frequency driving capability.

Each input has its own independently installed balanced input-stage amplifier. The signal is received and passed to the amplification stage in balanced configuration to reduce noise. IDM-01, an Integrated Discrete-Amplifier Module developed for the C1X preamplifier, is used alongside FET switches in the input selector to preserve micro-detail.

The amplifier’s mechanical construction is designed to control vibrations that could affect sound quality. Its chassis balances rigidity and flexibility, with an appearance shaped by the requirements of its mechanical engineering.

The top panel uses a Dual Honeycomb Grille, with honeycomb-shaped openings to improve internal heat exchange and reduce panel weight. 2 grilles of different thicknesses are stacked with their holes offset, dispersing vibrations. This design also supports a more open sound.

Aluminium blocks are used extensively in the body enclosures to support resonance-free operation. The front panel is machined from a 35mm-thick aluminium block. The top panel uses a semi-floating structure to reduce vibration, while the isolated feet have their own structure to reduce mechanical stress and support sound quality.

The Esoteric Grandioso M1X combines a high-current output stage, a separate pre-drive power supply and a mechanically controlled chassis within a design that prioritises simple circuitry and large-scale power delivery.