G-01XD

The Esoteric G-01XD is a Master Sound Discrete Clock with a custom SC1 crystal oscillator, advanced temperature control and 4 independent power supplies. Esoteric designed the oscillator, temperature control circuit and control program as a discrete circuit rather than using a general-purpose module, with the aim of producing sound closer to its engineers’ intentions.

Esoteric SC1 Custom Made Crystal

The Master Sound Discrete Clock is custom-made exclusively by Esoteric, from its high-accuracy oscillator circuitry to the crystal oscillator itself. The crystal material is intended to provide a natural tone quality, very low phase noise and stable operation when used with the G-01XD’s temperature control system.

Quartz crystals generate clock signals through vibration, or resonance, so the physical characteristics of the base material have a direct relationship with the resulting performance. Larger crystals can provide a higher drive level that is less affected by high resistance within the circuit, as well as more stable oscillation. Esoteric examined the cut shape, size and other manufacturing details when developing the oscillator. The SC1 crystal is based on a reliable quartz variety developed for the aerospace industry and was produced specifically for musical reproduction.

The crystal material is grown slowly over an extremely long period before being SC, or Stress Compensated, cut into its final shape. To control its resonant vibration, Esoteric selects only pieces whose centre frequency fluctuations fall within its strict standards. The SC1 is the largest mass-produced crystal in its class.

Master Sound TC, Esoteric's Proprietary Temperature Control Program

Temperature affects crystal frequency accuracy, making temperature control central to maintaining clock accuracy. Esoteric’s Master Sound TC, where TC means Thermo-Control, combines dedicated hardware with control software developed in-house. Unlike a typical OCXO, which keeps its crystal in an oven at a constant temperature, the Master Sound TC system uses a programme customised for each crystal. The oven temperature is controlled to keep each crystal at the temperature where it operates most stably, producing a natural and pure 10 MHz clock signal.

4 Independent Power Supplies

All circuits in the Master Sound Discrete Clock are discrete, with separate power rectification circuits for the oscillator circuit, buffer amplifier, heater and control circuit. A large toroidal transformer supplies the oscillator circuit and buffer amplifier, supporting the instantaneous power and purity of the clock signal. The heater and control circuits use a separate EI core transformer. This arrangement prevents mutual interference between the circuit blocks.

Esoteric-HCLD Output Buffer Circuit

The G-01XD uses the Esoteric-HCLD output buffer amplifier circuit originally designed for the Grandioso C1X preamplifier. Its current transfer capability and 180 MHz wide frequency response are used to provide a pure 10 MHz sine wave clock signal to connected digital players.

4 10 MHz Sine Wave Clock Outputs Compatible with Adaptive Zero Ground Mode

There are 4 10 MHz sine wave clock output terminals, each with a toggle switch. The switch selects normal mode or Adaptive Zero Ground mode. In Adaptive Zero Ground mode, the ground level of each output terminal is driven to 0 V, the signal’s reference potential, allowing the preferred operating mode to be selected.

Custom-designed Coaxial Cable with MIL-standard SMA Connectors

A custom coaxial cable selected for use in the critical internal wiring is fitted inside the G-01XD. Its connectors are gold-plated SMA types compliant with MIL standards. The outputs use gold-plated BNC connectors with precisely matched 50 Ω impedance to improve transmission reliability and reduce loss.

Unique Chassis Construction

The chassis is designed for a master clock that is sensitive to vibration. Its front and side panels use thick-walled, heavy-duty aluminium to suppress external vibration. Inside, the Master Sound Discrete Clock module is freely mounted and mechanically grounded by its own weight, without mounting screws.

Esoteric’s Pinpoint Foot System, Patent No. 4075477 and No. 3778108, also holds the foot base against the lower chassis through the weight of the chassis rather than screws. Reducing the number of screws limits stress concentration in these vibration-sensitive components and allows the chassis to damp vibration naturally. The top plate has a semi-floating structure and is not fixed with screws.