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Snake Charmer Compressor:

The “compression” control affects two characteristics
of the compression action, namely: “ratio” and “threshold.” The
threshold is a predetermined reference voltage that can be used to
determine the parts of a guitar signal that require compression. When
below this threshold the guitar signal is permitted to pass through the
pedal’s circuitry unaffected. However, as soon as peak transients exceed
the predetermined voltage, the compressor circuitry kicks in. By
effectively reducing the pedal’s gain the amplitude of the peak is
instantaneously reduced.
Signal reduction can be subtle or more extreme,
depending on the amount of gain reduction applied for a given peak in
the input voltage. This pretty much defines the term ratio (i.e. amount
of gain reduction relative to input peak).
This control also increases the make-up gain in
synchrony with the ratio and threshold levels. Without this the overall
level of the pedal would drop on higher compression settings. This means
that sounds can be quickly dialled in without the need to play around
with a separate gain control. Naturally, it also means that any
background noise will become more apparent on extreme settings as the
overall gain will be very high prior to gain reduction.
GAIN REDUCTION INDICATOR
This led will light up when attenuation is taking place. This is
useful as it provides visual feedback to the user – allowing them to
see, in a clear and concise way, the results of tweaking pedal settings.
HIGH/LOW SWITCH
The “high/low” switch lets the user choose between two overall levels of
ratio. In the low position the ratio is similar to that of many classic
guitar-orientated compressors. In the high position the effect is more
pronounced - creating loud, percussive attack transients at the start of
each note (on slow attack times), or completely replacing attack
transients with dips in volume, as the gain is immediately reduced by an
excessive amount (on fast attack times).
ATTACK
”Attack” determines how quickly the gain reduction kicks in after the
initial detection of a peak transient. Slower attack times will result
in a percussive quality being added to the natural transients of both
chords and single notes. This is because for a short instant the gain
reduction doesn’t engage and the note is momentarily amplified by the
un-attenuated make-up gain. These short but loud transients will be
limited by the cool tube as the valve enters its non-linear region. With
fast attack times the gain reduction is introduced immediately and
transients are quickly reduced. The attack time is shortest with the
dial turned fully anti-clockwise and increases as the dial is turned
clockwise.
RELEASE
“Release” determines the amount of time during which the gain is
attenuated. Consider the case with no, or very little release time. Once
triggered, the gain reduction will remain intact until such a point as
the input peak has passed. i.e. the gain reduction is purely influenced
by the nature of the program material (in this case the guitar). The
user may set a release time in order to hold the gain at the attenuated
level, for a finite period of time (regardless of any reduction in input
signal – However, subsequent peaks can trigger greater gain reduction
during this time.). The release control can be adjusted with greater
release times being heard as the control is turned clockwise. Perhaps
the easiest way to evaluate release time is to play a short and loud
dampened chord and observe the amount of time it takes for the
compression indicator to switch off.
HIGH-END EMPHASIS
This control simply fine tunes the amount of compression applied to the
“top-end” of the guitar’s signal. This is done by using a filter to
either boost or cut the higher frequencies present in the “side-chain”
circuit (i.e. the signal that drives the “opto”/compression device). In
the centre position the frequency response of this filter is flat. As
you turn the dial anti-clockwise, high frequencies are cut, and so the
compression to the “high-end” is reduced. The treble now rings-out above
the bass – giving chord parts greater jangle! Turning the control
clockwise from the centre position boosts the high frequencies,
producing even greater compression. Overall dynamics are flattened and
“digging-in” to lead parts produces very pronounced compression effects.
VOLUME
This control simply adjusts the amount of signal coming out of the
pedal.
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O
ver the Top Boost:

O.T.T.B.
VOLUME:
This controls the overall volume (output) of the pedal.
BASS:
This adds low end girth at higher settings and a warm round
smoothness at lower settings
CUT:
What this does is the opposite of what you may think. Turning it
clockwise will decrease the higher frequencies and turning it
counterclockwise adds higher frequencies.
TREBLE:
Thiswill take your sound from a cutting attack at one extreme to
smooth and liquidy at the other.
GAIN:
This varies the overall gain of the pedal from bluesy and mellow to
fat and saturated.
STANDARD/CUSTOM Switch:
- Standard: When this is selected the EQ (Treble and Bass)
becomes very interactive. As you increase the Treble or Bass, mids are
decreased and conversely, as you decrease Treble or Bass, mids are
increased just like a traditional AC30 Top Boost amplifier .
- Custom: When this is selected the EQ becomes less
interactive like an AC30 Hand Wired or an AC15TB.
You can use the OTTB as a booster pedal to drive the
input of your amp by setting the Gain low and the Volume high.
Conversely, set the Gain high and the Volume low for an overdrive from
the pedal itself.
GAIN:
This varies the overall gain of the pedal from mellow and warm to
grinding and ripping or anywhere in-between!
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Big Ben Overdrive
Preserve your amp’s warm, silky tone while pushing
your sound into overdrive! The tube-powered Big Ben Overdrive pedal
responds to your playing dynamics and cranks out that extra firepower
when you really dig in and want to cut through. The Gain knob varies the
overall gain of the pedal from bluesy and mellow to fat and saturated,
while the Tone knobs adjusts that overall tonality of the pedal. As with
all COOLTRON pedals, the Big Ben’s true bypass allows you to let your
signal flow through untouched. |
Bulldog Distortion
With dual channels – each with its own Gain and Volume
controls – and growling tube tone, the VOX Bulldog Distortion pedal adds
extra bite to your fret burning maneuvers. Gain 1 dishes out vintage
distortion while Gain 2 packs a more modern, aggressive sound with
slightly scooped mids. Both are adjustable from subtle to completely
over the top. A Bass control adds extra low end thump at extreme
settings and a warm, round mellowness at lower settings. And with the
Gain 2 Voice control you can independently tailor the second channel’s
hell-raising tone. A Treble control will take your sound from a biting
attack at one extreme to smooth and liquid at the other. The Bulldog
also is equipped with true bypass. |
Brit Boost
Give your tone extra muscle with the Brit Boost pedal.
The Treble Boost setting pumps up the treble and upper middle
frequencies, just like you’d expect from a vintage Treble Booster pedal.
In the Full Range Boost position the pedal enhances all frequencies. It
adds low mids and bottom end to the Treble Boost mode and is good for
pushing a slightly overdriven amp into heavy overdrive. A gain knob
varies the overall gain of the pedal from mellow and warm to grinding
and ripping! Plus, a Tone knob adjusts the overall tonality of the
pedal. Of course, there’s a true bypass switch that lets your signal
flow through without coloring the tone. |
Both the Vox Cooltron
Big Ben and Bulldog Distortion pedals received the prestigious
"Platinum Award " in the September 2005 issue of
Guitar World Magazine.
Want to know how it all works?
Normally, tubes are used at high voltages and this
restricts their use in battery-powered devices such as guitar effects
pedals. Historically, attempts have been made to use tubes at low voltages
in what has been dubbed “starvation” mode, but these circuits don’t allow
the tube to function in an acceptable manner. The tube simply cannot be
biased to a satisfactory operating condition. Plus, the necessary heater
(filament) current is too high to deliver acceptable battery life. Imagine
how annoying it would be to have to change batteries every ten minutes
during a gig!
Here’s what makes the COOLTRON system tick. The COOLTRON circuit basically
operates by using two very special signal paths. The first is the “servo
circuit,” which provides the right conditions between the plate of the tube
and the grid. This achieves controllable, stable parameters for the tube and
provides the correct operating conditions for the tube to function as it
would if run at a higher voltage. The second circuit is a patented power
supply that provides a low voltage, low current supply to the heater
elements in the tube. Since the tube is now running at such a reduced supply
level, the anode current is much smaller than normal. This means that the
amount of heat required at the cathode to achieve sufficient cathode current
emission is much smaller – hence the ability to run the heaters at a lower
level and for COOLTRON pedals to run for 20 hours on 4 x AA batteries!
The COOLTRON system provides true
tube sonic performance at very low voltage and at reduced heater
current – ideal for inclusion into guitar effects pedals. COOLTRON guitar
effects pedals offer valuable tube type sonic performance.
Specifications:
- Bulldog Distortion controls – Gain 1,
Volume 1, Gain 2, Volume 2, Bass, Treble, Gain 2 Voice, Gain1/Gain2
Switch, True Bypass
- Big Ben Overdrive controls – Gain,
Tone, Volume, True Bypass
- Brit Boost controls – Treble
Boost/Full Range Boost, Gain, Tone, Volume, True Bypass
- Tube: 12AU7
- Power: 4 x AA batteries (allows 16
hours of operation)
- Dimensions: 1 6.84 cm (6.63”) (W) x
15.55cm (6.12”) (H) x 6.4cm (2.52”) (D)
- Weight (without batteries): Bulldog
Distortion 1.07kgs (2.36 lbs.), Big Ben Overdrive 1.02kgs (2.25 lbs.),
Brit Booster 1.05kgs (2.31 lbs.)
- Options: 9V AC adapter
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