Thermionic Culture THE CULTURE VULTURE Stereo Valve enhancer User Manual
Page 6
© Thermionic Culture Ltd, October 2005
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General Operational Hints
The performance of the Vulture is inherently reliant upon the
volume and content of the audio signal going through it. It would
be virtually impossible to give example settings to the user and
expect them to work for any sound. Instead it is more useful to
point out the guidelines that govern the way the Vulture may be
used.
The first thing to note is that triode and pentode settings give
quite different effects. The triode (T) setting on the Vulture will
give a subjectively smooth, rich kind of a sound to the distortion.
If this seems a little too ‘slow’ sounding, then a change to the
pentode (P1) setting will give a harder more edgy sound. The
P2 setting is more unusual than the other two settings and can
produce some quite weird effects.
Using the bias control has a major effect on the distortion. The
cleanest setting for the bias is at about 0.3 mA on the meter. If
the bias is increased, then the Vulture will tend to allow more of
the signal through and hence will distort the signal more readily.
This will also give an increase in volume and subjectively cause
the signal to sound rounder and more harmonically rich. If the
bias is decreased from 0.3mA then the Vulture will approach a
situation in which it is trying not to allow signal through it. This
has the effect of distorting the signal in a less linear way. To the
ear the sound may have slightly more edge or crispness to it
when this happens. If the bias gets towards zero then the
Vulture will begin to only allow the peaks in signal through. This
has a ‘gated’ effect and may come in useful on drum sounds or
anything that might sound good being chopped up in such a
way.
The P2 setting reacts quite strangely to decreasing bias and
with just the right amount of signal level will cause a frequency
doubling effect to occur. To hear this effect a bias of 0.15mA to
0.2mA will give the right conditions and all that needs to be
done is to adjust the signal level until the effect is heard.