Cooltron Pedals

 

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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.

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!

 

 

 

 


 

 

 

 

 

 

 


 


 


 

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