Thermionic Culture THE FREEBIRD 3 channel equalizer - Manual (Page 5)

©Thermionic Culture Ltd., May 2011 4
2 EQ Style
The Freebird EQ is based around a Baxendall type circuit.
This gives the user two shelving controls, one each for low
and high end frequencies. There is a switch adjacent to each
shelving gain control which changes the frequency at which
each shelf operates between two positions. The type of
control provided by the Baxendall circuit is incredibly
versatile despite the apparently broad parameters. The
overall tone of a sound can be quickly and effectively
changed with a high degree of musical feel given to the user.
The presence control gives a very unique EQ curve, which is
a combination of shelf and bell curves. The given curves are
set at different gains and frequencies for each switch
position. The presence control is a feature unique to The
Freebird that is derived from Vic's early design. Extra
frequencies and gain settings have been included to make
the control as versatile as possible.