Phoenix Audio Gyrator EQ/500 is a four band equaliser in 500 series format built on gyrator circuits. Instead of inductors, the band is defined by an arrangement of an amplifier, resistors and capacitors, which shapes tone gently while keeping the character of the original signal intact.
Twenty-one positions instead of a knob set by eye
The real trouble with an analogue equaliser in a mix starts at revision time: the client comes back two weeks later and you have no idea exactly where the knob was. Here every band sits on a stepped pot with twenty-one positions across a ±16 dB range, so a setting is a number you write down and return to step for step. The same applies to running a pair of modules: matching left to right stops being a trim by ear.
Four bands, twelve frequencies
The high band is a shelf at 25 kHz, 15 kHz and 10 kHz, where 25 kHz opens the top without pushing presence. The high mid is a bell at 6 kHz, 3 kHz and 1.6 kHz, the low mid a bell at 800 Hz, 400 Hz and 200 Hz, and the low band a shelf at 130 Hz, 80 Hz and 40 Hz. On top of that sits a high pass filter at 80 Hz with a 12 dB per octave slope, which clears rumble and stand knocks before they ever reach the equalisation.
KEY FEATURES
- Four band gyrator equaliser in 500 series format
- Twelve selectable frequencies, three per band
- Cut and boost range of ±16 dB per band
- Stepped potentiometers with twenty-one positions
- Shelving response on the high and low bands
- Bell response on both mid bands
- A 25 kHz setting that opens the top without presence
- High pass filter at 80 Hz, 12 dB per octave
- DSOP-2 Class-A output stage
- Custom-wound output transformer
- Internal 24 V supply for full headroom
- Full recall of settings for mastering work
TECHNICAL SPECIFICATIONS
- Format: 500 series, API standard
- High band: 25 kHz, 15 kHz, 10 kHz, shelving
- High mid: 6 kHz, 3 kHz, 1.6 kHz, bell
- Low mid: 800 Hz, 400 Hz, 200 Hz, bell
- Low band: 130 Hz, 80 Hz, 40 Hz, shelving
- Cut and boost: ±16 dB per band
- High pass filter: 80 Hz, 12 dB per octave
- Frequency response: 20 Hz to 20 kHz (±0.5 dB)
- Maximum output: +26 dBu at 1 kHz
- Noise floor: -90 dB (20 Hz to 20 kHz)
- Internal power rail: 24 V
