The Metrum Acoustics AMETHYST is a single-ended DAC (Digital-to-Analog Converter) designed to deliver high-quality audio performance, featuring a "forward correction technology" for enhanced sound detail and accuracy. This device serves as an entry-level model within Metrum Acoustics' product line, incorporating advanced features borrowed from their higher-end Pavane and Adagio models.

Function Description

The AMETHYST's primary function is to convert digital audio signals into analog signals, which can then be fed to an amplifier or headphones. It utilizes two Transient R2R ladder DAC TWO modules, enabling it to handle high sampling rates and deliver a fast and accurate audio experience. The device is designed to provide true 24-bit performance, ensuring the retrieval of very low-level information and detail from audio sources.

A key feature of the AMETHYST is its integrated headphone amplifier, which includes its own dedicated volume control. This allows the device to function both as a standalone DAC for an amplifier and as a high-quality headphone amplifier. When headphones are connected to the front panel, the analog outputs on the rear are automatically disabled, diverting all power to the headphone amplifier for optimal performance. Conversely, when no headphones are connected, the device operates as a standard DAC, with its analog outputs active and the volume control muted for the main outputs.

The AMETHYST incorporates a conventional analog volume control that is directly coupled to the D/A output board, ensuring detailed sound quality. The design emphasizes a small, integrated form factor, combining both digital and analog processing within a single unit.

Usage Features

The AMETHYST offers multiple digital input options, including optical (Toslink), coaxial, and USB, providing flexibility for connecting various digital audio sources such as computers, CD players, and streamers. The optical input supports sampling rates up to 96 kHz, coaxial inputs handle up to 192 kHz, and the USB input can manage up to 384 kHz. For Windows operating systems, special drivers are required for USB connectivity, while Linux and MAC systems do not need additional drivers.

Operation of the AMETHYST is straightforward, primarily managed by a single button on the front panel. This button allows users to toggle through the available digital inputs (USB, Optical, Coax 2, Coax 1) and switch the device between its "standby" state and active mode. An orange LED on the left side of the DAC serves as an error indicator, illuminating when no digital data is available for the selected input and turning off once valid data is received.

The headphone amplifier is designed to drive a wide range of headphones, with impedances starting from 16 Ohms up to 1000 Ohms. The volume control for headphones is independent of the main analog outputs, ensuring that adjusting headphone volume does not affect the signal sent to an amplifier.

For connecting to an amplifier, the AMETHYST provides RCA outputs. These outputs deliver a fixed level standard Redbook 2V output, directly from the DAC TWO modules without an additional output stage, which helps preserve signal integrity.

Maintenance Features

The AMETHYST is designed for user-friendly operation with minimal maintenance requirements. Users are advised to clean the apparatus only with a dry cloth. It is important to avoid installing the device near heat sources and to unplug it during lightning storms or when it will be unused for long periods.

The manual emphasizes that there are no user-serviceable parts inside the AMETHYST DAC. Any servicing requirements, such as damage to the power cord, liquid spills, or operational malfunctions, should be referred to qualified service personnel.

A crucial note for users is that the AMETHYST will reach its maximum performance after approximately three to four weeks of usage, indicating a "burn-in" period for optimal sound quality.

For initial setup, users should connect all interconnects (digital inputs and analog outputs) before connecting the mains power cable. This helps ensure proper signal routing and prevents potential issues. The device is designed to operate with a grounded power outlet, and users should verify that the power requirements on the back of the unit match their specific country's electrical standards.

The device's robust design, including galvanic isolation for coaxial inputs, helps prevent ground loops, contributing to stable and clean audio performance. The internal power supply is designed to provide substantial energy reservoirs, ensuring smooth and efficient power delivery to the DAC modules and headphone amplifier.

METRUM Amethyst - Package Contents; Included Items

Table of Contents

Related product manuals