Here’s a new demo by Shawn Tubbs about the Pettyjohn Filter, an EQ shaping utility pedal.
The FILTER is a simple but powerful semi-parametric guitar equalizer featuring three individual bands to cover the range of a guitar effectively. The circuit has been carefully designed with high headroom for low noise, low distortion performance, while offering up to 12dB of boost OR cut with the ultra transparency and musicality of an analog recording console EQ.
The Low band is switchable between a bell filter at 150 Hz or a Low shelf at 100 Hz and has been voiced to provide very powerful low-end without feeling muddy, even at high boost levels. The High band is a carefully voiced bell filter with a center point at 6 kHz or 4 kHz. The High band filter is highly useful for dialing in the perfect amount of sweet articulation or smoothing harsh overtones with a touch of analog magic that console EQ is known for.
The MID band is a tip of the hat to some of the most beloved console EQs ever made and features a premium inductor driven bell filter with three selectable frequencies at 460 Hz, 780 Hz and 1.8KHz. These frequencies are key musical points in the guitar’s range that can be very useful to control with a dedicated EQ.
Beyond utility value, the use of a real inductor results in a rich, dimensional sound that makes the “mids” come alive with extra harmonics, especially when pushed hard. Vocal, wah type tones are even available when the mid bell is pushed to the extreme and can be perfect for getting a solo track to cut through the mix. With plenty of gain on tap, use the LEVEL control to achieve unity gain or boosting with any EQ curve.