Crane Song Insigna 500 Series EQ
Crane Song Insigna is a coloring / shaping eq with 3 bands plus Hi cut and Low cut filters.INSIGNA is a tube equalizer in a 500 series package, using a dual triode circuit with a 12AX7 tube.
The eq has 24 db/oct high pass and low pass filters, each with 7 frequencies.
The top and bottom band are shelving. each with 8 selectable frequencies.
The mid band is peaking with 8 frequencies.
The three bands work by using buffered RC circuits in the negative feedback path around the tube amplifiers. The result is a fat sounding eq, rich in second harmonic triode tube color.