VOX Cooltron - Brit Boost

Introducing the Cooltron series of effect pedals, seven very special stompboxes that use a 12AU7 preamp-type tube at low voltage to deliver the kind of tone that, until now, would have been impossible to achieve in a battery-powered pedal.

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.

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 16 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

• 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 (excluding batteries): Brit Booster 1.05kgs (2.31 lbs.)
• Options: 9V AC adapter