Thermionic Culture The ULTRA Vulture User manual

Thermionic Culture Ltd. 2021 1
WARNING
For your personal safety, please read this operating manual and
this warning thoroughly before using the equipment.
This unit must be installed in such a manner that operator access
to the mains plug is maintained. Where the product is to be rack
mounted, this may be achieved by having access to the
disconnection device for the whole rack.
To reduce the risk of electric shock, it is essential that the unit is
disconnected from the mains supply before removing the cover.
Please also note that the power supply capacitors within this unit
can remain charged even after the mains supply has been
disconnected. It is essential that these capacitors are discharged
after the mains supply has been disconnected and the covers
have been removed.
In the event that this unit has been dropped or has suffered an
impact, an electrical safety test must be carried out before
reconnection to the mains supply.
This equipment is not intended for use in explosion hazard
environments. It must be used and stored in studio conditions,
such that the ambient relative humidity does not exceed 80%, nor
is the temperature to be allowed to drop to a level, which would
cause dew point to be reached.
The Ultra Vulture, though valve based, does not run exceptionally
hot. Other equipment can be mounted in the rack directly above
and below it, as long as the rack is well ventilated and the
ventilation slots are not obstructed.
It is not advisable to operate this equipment unless all valves,
especially the Output valve in the centre, are in place.

Thermionic Culture Ltd. 2021 2
CONTENTS
Section Page
1 Introduction 3
2 Controls & Meters 4
2.1 Drive 4
2.2 Output Level 4
2.3 Bias (and meter use) 4
2.4 Function Switch 5
2.5 Filter 5
2.6 Presence 5
2.7 Bypass 5
3 General Operational Hints 6
4 Inputs and Outputs 8
5 Servicing and Maintenance 9
5.1 Valves 9
5.2 Operating voltage / Fuse 10
6 Specification 11

Thermionic Culture Ltd. 2021 3
1 Introduction
The Culture Vulture is universally renowned as the first and only
all valve unit, dedicated to producing the best harmonic
distortion money can buy.
THE ULTRA VULTURE takes the Culture Vulture to a new level
making it more suitable for accurate stereo uses, including
mastering, where extended frequency response, low noise and
re-callability are of prime importance. Transformer balanced
line ins and outs are standard, on XLR connectors.
Although the unit can be "clean” (less than 0.2% THD), added
valve saturation may be quite desirable, improving naturality
and smoothing off unwanted digital spikes. But The Culture
Vulture can be used for distortion effects! Push it and try it!
The user has total control over the type and amount of
distortion, which can be changed from even to odd harmonics or
a combination of both. Starved, the sound from The Vulture
becomes thin and loses its body, overfed, it becomes fatter.
. The Function switch now has 2 "effects” positions, ‘P2’ & ‘P3’.
The extra ‘+10dB’ drive position gives some of the bite of
'Overdrive’ but with far less noise. When ‘+10dB’ is selected
(only) the ‘Presence’ switch is available. The ‘-10db’ output
switch allows the unit to be driven into extreme distortion but still
have an easily achieved stereo balance. However, the ‘P2’ and
‘P3’ positions will become so extreme that true stereo won’t
always be applicable.
All pots, except ‘Bias’, are indented for easy recall. Use meter
readings to accurately recall ‘Bias’ settings.
A test report comes with each unit indicating best settings for
mastering.

Thermionic Culture Ltd. 2021 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 ‘+10’
position increases the gain by 10dB and adds some top
end for extra bite. 'Overdrive’ is 30dB 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 2nd valve, so the higher it’s set the more
effect. It should be used in conjunction with the ‘Output
Level’ control to keep overall levels where they are desired.
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, it’s advisable to set the rotary control at 8-12
(check test report) with the ‘-10dB’ 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 ‘Output level’.
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 fatter,
but current above 0.6 mA will shorten valve life. The best
setting for low distortion is usually 0.25 - 0.3 mA (see test
report for exact figures with valves supplied).