Audiotales 1951 EQ

Audiotales 1951 EQ is a tube mastering equalizer with two boost-only bands and two filters. The circuit runs on NOS Sylvania 6SL7 WGT and 6922 tubes, and every unit is assembled by hand in France.

Two curves instead of two separate units

Each band switches between a shelving response and a Baxandall curve. The difference matters exactly in mastering: a shelf lifts decisively from its corner frequency, while Baxandall works broadly and gently, so 1 dB at the top does not sharpen sibilance. One switch replaces the need for two equalizers in the chain.

Built for material that is already mixed

The low band covers 20 to 150 Hz and the high band 6 to 51 kHz, so the 1951 works at the extremes rather than in the midrange where vocals and guitars live. Headroom of +28 dB at 1 kHz and a noise floor of -105 dB mean the equalizer will not narrow the dynamics of a finished mix. Channel matching stays within 0.1 dB from 20 Hz to 51 kHz, so the stereo image holds still. Each band has its own bypass, and a separate hardwired master bypass gives a genuinely unprocessed reference.

KEY FEATURES

• Tube mastering equalizer with two boost bands and two filters
• Switchable shelving and Baxandall response curves
• BARYTONE and AIRCAP controls for shaping the band extremes
• NOS Sylvania 6SL7 WGT and 6922 tubes
• Output level control
• Per-band bypass plus a hardwired master bypass
• Hand-assembled in France

TECHNICAL SPECIFICATIONS

• Type: tube mastering equalizer
• Low band: 20 Hz - 150 Hz
• High band: 6 kHz - 51 kHz
• Response curves: shelving and Baxandall, switchable
• High cut filter: 3 dB per octave
• Low cut filter: 6 dB per octave
• Headroom: +28 dB at 1 kHz
• Noise floor: -105 dB, maximum -95 dB
• Frequency response: 15 Hz - 30 kHz, +/- 3 dB
• Channel matching: 20 Hz - 51 kHz, +/- 0.1 dB between channels
• Input impedance: 10 kOhm
• Output impedance: 510 Ohm
• Tubes: NOS Sylvania 6SL7 WGT and 6922