Thermionic Culture THE SOLO VULTURE High Gain Distortion Unit User Manual

Page 5

Controls & Meters

2.1 Input gain

This switch varies the amount of gain in the 1

stage of the

Solo

Vulture. The figures, 5 to 35 dB, represent the gain

available to the Clean channel with the Clean output
control set at 8, so 5 dB more gain is actually available.
The first stage goes straight to the output stage when
Clean is switched in. When Dirty is selected, a top lift is
introduced in the 25 & 35 dB positions to give more “bite”.

2.2 Drive

This control varies the amount of signal fed to the 6AS6
type distortion valve. The higher it’s set the more gain and
distortion.

2.3 Presence

A 3 position switch. 1 “flat”, 2 a broad mid lift favouring the
upper mid range, 3 a broader mid lift with more boost.

2,4 Bias (and meter use)

This control varies the current through the 6AS6 type valve
by changing the positive voltage on its cathode. The actual
current is shown on the milliameter. When the Vulture is
starved of current the sound appears thinner and when
over-fed it becomes warmer and fatter. The typical setting
is 0.25 – 0.3 mA, which also gives lowest distortion. When
the Solo Vulture is pushed to heavy distortion the meter will
twitch.

N.B.

The Bias control in naturally noisy in operation, but

should be quiet when set.