Preamplifiers — Gryphon Audio ZENA

The Zena is a dual mono line preamplifier which Gryphon Audio Designs builds in Denmark as the replacement for the Athena. Where the Athena used a ball-bearing volume control, the Zena adopts touch-sensitive buttons on a dimmable graphical vacuum fluorescent panel, and it was the first Gryphon preamplifier to accept an optional phono stage or DAC module either when bought or at a later date.

Key specs that matter

At the back, two balanced inputs use gold-plated Swiss Neutrik XLR sockets, while three single-ended inputs use gold-plated, Teflon-insulated RCA sockets, with outputs on a single XLR pair and two RCA pairs. Maximum gain is +18 dB. Input impedance is 50 kOhm balanced and 25 kOhm single-ended over 20 Hz to 20 kHz. Output impedance is 15 ohm on XLR and 22.5 ohm on RCA. Bandwidth runs from 0.1 Hz to 1 MHz at -3 dB, THD+N is below 0.005%, and the power supply holds 2 x 26,000 uF.

Engineering and use context

The circuit is zero-feedback, true dual mono, fully discrete, DC-coupled and Class A, with a high-speed discrete single-ended Class A input buffer. Signal stays fully balanced, with no conversion to single-ended before attenuation. Its microprocessor-driven relay attenuator offers 43 volume steps of 2 dB each, with no more than two resistors in its signal path at any time. The attenuator uses ultra-precise SMD metal-foil resistors and hermetically sealed, gold-plated Pickering reed relays, and local shunt regulators give the supply an ultra-low output impedance. Tone controls, balance knobs, polarity inversion and a headphone output were left out for a shorter signal path, and internal wiring is minimal. Input level matching is available in the menu. The optional DAC module accepts PCM and DSD through USB, AES, optical and a pair of S/PDIF inputs, handling up to 384 kHz PCM and DSD512, and the optional phono module supports MM and MC cartridges. A minimalist aluminium remote with a built-in stand is supplied, and the unit carries EU CE approval.

Pairing

Green Bias works with Gryphon power amplifiers to control their Class A output dynamically. AV throughput can be assigned to input 2 on XLR or input 3 on RCA for a surround processor, and a 12 V DC link input and output let the Zena power up and down in step with linked components.

Alternatives

The Gryphon Essence Preamplifier is another Gryphon line preamplifier with a 43-step relay attenuator and optional phono and DAC modules.