Trilogy H1 Electrostatic Headphone Energiser

The H1 is an energiser for electrostatic headphones and the first product from Trilogy's Special Products Division. SPD products are, by their nature, niche and limited in production run, and each one is hand assembled and tested by Nic Poulson personally. After trialling variations of the Stax circuit used by many other manufacturers, Poulson concluded that the accepted wisdom and circuitry could not advance the product to Trilogy's design goals, and started again.

The result is a pure Class A, fully balanced circuit with wide bandwidth and zero feedback. Two toroidal transformers are used, one for heating the triodes and one for the rest of the H1. The tube circuit uses high transconductance military specification tubes throughout — four 6C3П input tubes and two 6H6П output tubes. Wiring is Teflon coated point to point silver plated copper, and the PTFE/Teflon output sockets have gold plated contacts, suiting Stax and similar electrostatic headphones at 580 volts bias.

Four inputs — two RCA and two XLR — sit at the rear, with one pair of electrostatic sockets recessed into the front fascia. Two versions are made: a direct mode model (DMV), which selects inputs remotely, and a fully functioned remote version that adds volume, balance and mute. A DMV can be upgraded to the full featured version by returning it to Trilogy for chip and firmware updates.

• Type: electrostatic headphone energiser; first Trilogy Special Products Division product
• Topology: pure Class A, fully balanced, zero feedback, wide bandwidth; two toroidal transformers
• Valve complement: 4x 6C3П, 2x 6H6П; approximately 5,000 hours service life
• Bias voltage: 580 VDC
• Inputs: 2 pairs XLR 3-pin female (66 kohms or greater); 2 pairs RCA (33 kohms or greater)
• Gain (max): 56 dB
• Frequency response: 10 Hz – 50 kHz +/- 0.5 dB
• Phase: phase correct (non inverting)
• Versions: direct mode (DMV) or full featured remote; DMV upgradeable at the factory
• Power consumption: 55 W / 1 W standby
• Dimensions / weight: 260 x 392 x 88 mm / 6.7 kg