Thermionic Culture Phoenix Mastering Plus Stereo Valve Compressor

Phoenix Mastering Plus
Stereo Valve Compressor

Thermionic Culture have released a new version of the Mastering valve compressor, the Mastering Plus. The classic hand built point to point wired soft knee compressor has a compression ratio from 1.2:1 to 5:1 at 15dB of compression and uses Mullard and Siemens valves and custom Sowter transformers.

Following on from the success of the previous models including the red face anniversary limited edition the new model features new switched and stepped rotary controls for quick and easy recall. The input gain features a 24 position ELMA, a 11 position ELMA for the Threshold, 6 position ALPHA attack and release and a 31 position OMEG stepped output pot. The same side chain filter section as previous versions has been retained.

The Phoenix is a stereo compressor, which can be used as a pair of mono compressors. It has a ‘soft knee’ or ‘variable mu’ characteristic in that the compression ratio increases with the amount of compression being used. Initial compression is 1.2:1 increasing to 5:1 at 15dB compression.

The Phoenix is being updated continually and this unit is the Master version (suffix M) with higher stability and faster release than earlier models. A side chain filter has now been added to provide 150Hz & 300Hz, but more permutations are possible when the MC is used in stereo mode with the link switch engaged.

The Master Phoenix is easier to recall as it has a mixture of indented and switched controls and the screwdriver adjustment on the chassis behind the meters controls the current through the valves on this unit, so this corrects to some extent for valve ageing. A screwdriver is supplied with the Master Phoenix and should be used periodically to adjust the meters to zero.

Stepped Input & Output controls * 6 position switched attack control * 7 position switched release control * 11 position switched threshold control

Key Features

• All valve design for greater presence and naturality.
• Completely free from solid state additives.
• Transparent compression.
• Punchy when pushed.
• Drive it hard for compression effects and distortion.
• Absolutely flat frequency response over entire audio range and beyond.
• Minimal phase shift giving a crisp and warm sound.
• Stepped Input & Output controls
• 6 position switched attack control
• 6 position switched release control
• 11 position switched threshold control
• Side Chain Filter - 75Hz & 150Hz plus permutations.

New Features

• 24 position ELMA rotary Input switch, +31dB gain
• 31 position OMEG stepped Output pot
• Chicken head knobs for Attack, Release and S/C
• New Input, Threshold and Output knobs
• ALPHA Side Chain filter
• All Mullard & Siemens valves

Phoenix Mastering Specifications

Distortion will increase with compression, typically 0.2% & 0.25% at 1kHz & 100Hz with 8dB compression. Attack and release controls are somewhat interdependent, for instance a change of attack setting may affect the release time slightly. Therefore, no times are given on the front panel.

Valve Complement (2ea)