Thermionic Culture THE CULTURE VULTURE Mastering Plus - Manual (Page 5)

©Thermionic Culture Ltd, 2010-2014 4
2 Controls & Meters
2.1 Drive
This control is really in 2 parts, a switch and a rotary pot.
The switch gives a coarse control and the pot a fine control
of the signal input level. At the first position “Normal” (for
line level signals) the frequency response is flat. The
“Drive” position increases the gain by 10dB and adds some
top end for extra bite. “Overdrive” is 28dB above “Normal”
and can be used for extreme distortion effects at line level,
also guitars and other low level sources.
The drive pot controls the amount of signal you are feeding
to the 2
nd
valve, a 5725, so the higher it’s set the more
effect. It should be used in conjunction with
2.2 Output Level
Again this control is in 2 parts, a switch (-10dB) and a
rotary control. This controls the signal going to the output
valve. Usually set rotary control between 0 and +4 with
switch down for low distortion at line level. Set the switch to
(-10dB) and reduce the rotary control when pushing the
distortion valve at other than P3, which always requires
maximum gain
2.3 Bias (and meter use)
This control varies the current through V2 by changing the
positive voltage on its cathode. The actual current is shown
on the milliammeter. When the Vulture is starved of
current the sound is thinner and when over-fed it becomes
warmer and fatter. The best setting for low distortion is
0.25 mA. When the Vulture is being pushed into heavy
distortion the meters will twitch. N.B. The bias pot is
naturally noisy in operation as all of the valve’s current is
flowing through it, but it should be silent when set.