Vox Cooltron series
The COOLTRON VibraVOX pedal uses 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.
Named after VOX's first amplifier tremolo circuit, the VIBRAVOX essentially recreates the unique and immensely satisfying Vib/Trem sound from a "traditional" AC30 and puts it into an effect pedal that can be used with any amp.
To increase flexibility additional user control and features have been added. By including two Speed controls and an effects assign switch (T1/T2, T1/V2, V1/V2), a number of possibilities become available. The Vox VIBRAVOX can be configured as a tremolo only or vibrato only pedal with two foot-switchable speeds. You can also choose to configure the pedal to switch between tremolo and vibrato. To top it off, the pedal automatically ramps between speeds, adding a taste of that unmistakable "rotating-speaker" sound.
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 guitar 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 the COOLTRON VibraVOX pedal.
- Connection: Input: x1 (guitar input), Output: x1 (line output)
- Controls: Depth, Ratio, Skew, Volume, Speed 1, Speed 2, Mode Select
- 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)
- Options: 9V AC adapter