Kallyste Amethyste - Open Box - Clearance

Open-box items in C condition are open box items that are not in like-new condition. They may show signs of wear, have packaging that is imperfect and be missing accessories. Clearance items are sold as is without a warranty guarantee and no returns. 

The Kallyste Amethyste is a reference headphone amplifier built for systems where transparency, control, and long-term musical involvement matter more than convenience features. Its hybrid dual-mono architecture combines a carefully matched tube preamplifier stage with substantial Class A/B output power, giving it the finesse to resolve small changes in tone and phrasing while retaining the authority needed for demanding headphones.

Amethyste is designed around the idea that amplification should preserve the character of the recording rather than impose one of its own. Wide bandwidth, fast transient response, selectable output impedance, and a separately engineered tube-rectified power supply allow it to work across a broad range of headphone designs while maintaining clarity, scale, and dynamic contrast.

Hybrid Dual-Mono Architecture

The Amethyste uses a hybrid dual-mono circuit with two strictly matched military-grade pentodes in the preamplifier stage. Keeping the left and right channels independent helps preserve channel separation and spatial definition, particularly when a recording contains subtle ambience, layered instrumentation, or closely placed performers.

The tube input stage is followed by a powerful Class A/B amplifier section. This combination brings together the dimensionality and tonal expressiveness associated with valves and the current delivery required for firm control over modern headphone drivers.

Power with Headroom

Rated at 15 watts RMS into 8 ohms, the Amethyste has substantial output capability for a headphone amplifier. That reserve supports clean transient peaks and keeps the presentation composed when music moves quickly from quiet passages to large dynamic swings.

Power alone does not determine how an amplifier sounds, but adequate headroom helps prevent compression and strain. Bass retains weight and shape, dense arrangements remain organized, and low-level information is easier to follow even during demanding passages.

Three Output Impedance Settings

Headphones vary widely in impedance, sensitivity, and electrical behavior. The Amethyste addresses that range with three selectable output impedance settings:

• Low for headphones from 0 to 100 ohms
• Mid for headphones from 100 to 300 ohms
• High for headphones from 300 to 600 ohms

This allows the amplifier to be better matched to the connected headphone rather than relying on a single output configuration for every load. The result is more predictable damping, gain behavior, and tonal balance across low-impedance planar magnetic headphones, conventional dynamic designs, and high-impedance studio or audiophile models.

Wide Bandwidth and Fast Response

The preamplifier section is specified from 15Hz to 150kHz at 0dB, while the amplifier section extends from 1Hz to 100kHz. That bandwidth reaches well beyond the audible range and supports stable phase behavior and clean reproduction of rapid transients within the frequencies we hear.

Rise times of 1 microsecond for the preamplifier and 2 microseconds for the amplifier reflect the circuit’s ability to respond quickly to changes in the incoming signal. Percussion, plucked strings, vocal articulation, and the leading edges of notes arrive with precision while the body and decay of the performance remain intact.

Tube-Rectified Power Supply

The power supply is physically and electrically separated from the main amplification circuitry and uses rectifier valves in an ultra-linear design. Isolating the supply helps keep power-related noise and vibration away from the low-level audio stages, while the tube rectification contributes to the amplifier’s carefully controlled power delivery.

This approach is especially important in a high-gain headphone system, where small amounts of residual noise can become audible. The Amethyste is engineered to maintain a quiet background so that room ambience, reverberation, and subtle musical textures remain available to the listener.

Premium Parts for Long-Term Performance

Kallyste builds the Amethyste with carefully selected components chosen for electrical consistency and durability. Nichicon oil-and-silk capacitors and Vishay Dale resistors are used throughout the circuit, supporting stable operation and close channel matching.

The component selection, dual-mono layout, tube matching, and separated power supply reflect a design intended for long-term use in a high-end headphone system. Amethyste is built as a dedicated component rather than an accessory, with the power and circuit sophistication expected from a full-size reference amplifier.

Key Features

• Reference hybrid headphone amplifier
• Dual-mono circuit architecture
• Class A/B amplifier operation
• Two strictly matched military-grade pentodes in the preamplifier stage
• Separate ultra-linear power supply with rectifier valves
• 15 watts RMS output into 8 ohms
• Three selectable output impedance ranges
• Low setting for 0 to 100-ohm headphones
• Mid setting for 100 to 300-ohm headphones
• High setting for 300 to 600-ohm headphones
• Wide-bandwidth preamplifier and amplifier circuitry
• Fast 1-microsecond preamplifier rise time
• Fast 2-microsecond amplifier rise time
• Nichicon oil-and-silk capacitors
• Vishay Dale resistors
• Designed for low-impedance, high-impedance, dynamic, and planar magnetic headphones

Technical Specs