Thermionic Culture Phoenix HG15 Single-Channel Valve Compressor and Mic Preamp

The Thermionic Culture Phoenix HG15 is a single-channel version of the Phoenix Stereo Compressor, adding a dedicated mic preamp stage with gain boosted specifically for valve and FET condenser microphones. With the Threshold set to Comp Out, the HG15 functions as a clean mic/line amp; switching in the Active EQ, Presence, and AIR controls adds tonal shaping before the compression stage; then engaging compression produces what Thermionic Culture describes as a gentle “super-natural” dynamic effect achievable only through valve compression. Two HG15 units can be linked for stereo operation via a phono-phono lead from the rear-panel Link socket, and the Side Chain Bass Cut switch is available in both mono and stereo configurations. The Output Level control operates as a reverse linear attenuator after the electronics, functioning both as a standard level trim and as a way to add “Attitude” by reducing output while increasing input drive.

Key Features

• Mic preamp with boosted gain — gain designed for valve and FET condenser microphones; moving coil types also compatible with loud or close-miked sources; Input switch: Line or Pad (ensure +48V is OFF when switching to Pad from a line source)
• Phoenix variable-mu soft-knee compression — the same gentle compression curve as the Phoenix SB; approaches limiter behavior at high compression levels; can be pushed for harmonic distortion effects
• Active EQ with Presence and AIR controls — Presence provides a broad mid/high lift; AIR adds high-end clarity; with Threshold set to Comp Out, these function as a standalone EQ/preamp
• Output Level control — reverse linear attenuator post-electronics; reduces output level for low-level destinations, or adds “Attitude” when used in combination with increased input gain
• Stereo link capability — connect two Phoenix HG15 units via phono-phono lead from rear-panel Link socket for stereo operation
• Side chain bass cut switch — reduces low-frequency triggering of the compressor; useful in both mono and stereo configurations

Specifications

• Channels: 1 (2 units linkable for stereo)
• Compression Type: Variable mu; soft knee
• Input Switch: Line; Pad (note: +48V must be OFF with Pad)
• EQ: Active; Presence (broad mid/high lift); AIR (high-end clarity)
• Output Level: Reverse linear attenuator (post-electronics)
• Stereo Link: Via phono-phono lead (rear panel)
• Side Chain Bass Cut: Yes
• Construction: Handcrafted in England