A
tube in a pedal? Pretty cool.
Introducing
the COOLTRON series of effect pedals, three 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.
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.
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:
- Big
Ben Overdrive controls Gain, Tone, Volume, True
Bypass
- Tube:
12AU7
- Power:
4 x AA batteries (allows 20 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
