Thermionic Culture THE EARLYBIRD 2.2 2 Channel mic, pre amp with eq - Manual (Page 5)

©Thermionic Culture Ltd., September 2010 4
2 Controls
2.1 Function
This control selects the basic operating mode of the
Earlybird. The pre-amp can be aligned to operate as:
300Ω:-
A mic-amp with an input impedance of
300Ω
1200Ω:- A mic-amp with an input impedance of
1200Ω
PAD:- A mic-amp with an 18dB attenuating pad in
front of its transformer.
LINE:- A pre-amp that accepts line level signals
PULLET:- A pre-amp that provides the make-up gain
for the passive EQ network provided by the
Pullet in order to bring the signal back up to
line level.
2.2 Gain
This control selects the gain setting that the Earlybird
is operating at. The Gain is varied in four steps of 8dB.
i.e. 32dB to 60dB (mic), -8dB to 16dB (line).
2.3 Bass cut
The response is flat when this switch is fully anti-
clockwise. It acts as a HPF at 40Hz with a
12dB/octave slope, a little gentler at 100Hz and is a
shelving filter at 800 Hz.
2.4 Active lift
The three bands of active lift work in the negative
feedback loop. They are most effective at the first two
gain settings (36/-8 to 44/0), then less effective at 52/8
and almost out at maximum gain (60/16) as feedback
is reduced in the circuit to increase gain.