Buzz Audio Zodiak Tilt-N-Filter Equalizer

The Buzz Audio Tilt-n-Filter EQ idea was conceived by Zak Cohen, owner of the Woodshop Recording Studio, and it is based on a series of plug-ins Zak would routinely set up to equalize music tracks recorded direct into his DAW. The Zodiak reproduces this concept with the same series of eq elements - but in the analog domain, so it can used ahead of the DAW input. The main element of the design is the Baxandall style Tilt EQ circuit (originally found on the Quad 44 hifi preamplifer from the 1970s). The concept of a tilt EQ is not new, but with the addition of a fully parametric midrange band and high and low cut filters, the Zodiak caters for a wide range of applications that would otherwise require multiple processors.

This configuration utilizes high-end Texas Instrument ic opamps in the signal path with with an electronically balanced output.

All ic opamps are mounted on sockets so it is possible to experiment with your own choice of amplifiers if desired.

Controls and Functions:

The Zodiak is a dual channel equalizer with the following functions on each channel.

• LO CUT - a high pass filter that sweeps from 26 Hz to 220 Hz with a 12 dB per octave slope and its own IN/out switch
• HI CUT - a low pass filter that sweeps from 2.3 kHz to 21 kHz with a 12 dB per octave slope and its own IN/out switch
• BELL SWEEP - this section is the parametric midrange control with 10 dB of CUT and BOOST available - the FREQ control covers 65 Hz to 8800 Hz with the upper range activated with the HI button - the BANDWIDTH control offers narrow to wide bell shaped curves - this section also has it's own IN/out pushbutton switch
• TILT EQ - this control is always in circuit when the channel is switched IN - clockwise rotation will boost the treble and cut the bass, anti-clockwise rotation will cut the treble whilst boosting the bass
• OUTPUT - this control allows you to trim the output level to match the next device in your chain and has a + or - 8 dB range
• PEAK - this LED will light when levels inside the Zodiak signal path exceed +22 dBu
• POWER - A handy power on/off switch and associated power LED common to both channels and conveniently located on the front panel where it should be