Thermionic Culture THE EARLYBIRD 4 4 Channel mic. Pre amp - Manual (Page 4)

©Thermionic Culture Ltd., July 2014 3
1 Introduction
The Earlybird 4 is a four-channel mic-amp employing a
balanced push-pull all valve circuit, which as far as we know,
is unique in this application. The use of this type of circuit
gives seriously low noise, plenty of headroom and means a
very natural interpretation of whatever sound the microphone
is picking up, whether the mic is valve, dynamic or FET.
The Earlybird 4 mic amps are improved versions of the
Earlybird 1 and 2 series. They have improved Sowter input
and output transformers and traditional point-to-point hand
wiring by experts, eliminating the (slight) performance
degradation occurring when using circuit boards. The phase
shift is therefore very small and the distortion so low as to be
almost unmeasurable, especially in the mid range at the
most used gain settings. There is a natural warmth to the
sound but there is no compromising the frequency response,
and of course no solid state in the audio chain so no
“hardening” of the sound.
The Earlybird 4 should be considered as probably the
best microphone amplifier ever made.
“It’s like connecting a wire with gain to a microphone”.