Owner’s Manual

Many thanks for adding the VOX COOLTRON Bulldog Distortion /Big Ben Overdrive / Brit Booster pedal to your rig. Our main goal is to provide you with the most toneful products anywhere and we believe you’ll enjoy using these pedals as much as we enjoyed designing them!

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What is COOLTRON?

COOLTRON is the name that we have given to a new way of using preamp type tubes at low voltage. In our case we chose a 12AU7.

Tubes are normally used at high voltages, and this is the recognised way of using them, but it negates their use in battery-powered devices such as guitar effects pedals which is what COOLTRON is!

Historically, attempts have been made to use tubes at low voltages, usually termed as being used in “starvation” mode. Unfortunately, these circuits have severe problems in the tube functioning in an acceptable manner. One problem is being able to bias the tube to a satisfactory operating condition. Another problem is that the necessary heater (filament) current is too high to provide adequate bat- tery life which we all know would be annoying when you have to change batter- ies every ten minutes during a gig.

The COOLTRON system gets over both these problems and provides true tube sonic performance at a very low voltage and at a reduced heater current – ideal for inclusion into the aforementioned guitar effects pedals – and therefore can give these pedals a vast improvement by giving valuable tube sonic performance.

Basic Operation

The COOLTRON circuit basically operates by using two very special circuits:

A)To achieve the required biasing function, a unique circuit is used that provides the right conditions between the anode (plate) of the tube, and the grid. In general terms this circuit is called a “servo” circuit, and replaces the normal self-biasing networks that would normally be used. Although not the same circuit, this servo theory is used many times in high-end tube hi-fi, to achieve controlled stable parameters.

B)The heaters are provided with a special power supply that provides a low voltage and low current supply to the heater elements in the tube. Due to the servo-biased tube circuit providing the correct operating conditions for the tube, the tube now functions as it would if run at a higher voltage – i.e. the signal excursions can be operated linearly, pro- viding balanced clipping conditions, and with the right harmonic & distortion characteristics – even when running from a B+ of only 6 volts. Both of these conditions are virtually impossible to achieve using nor- mal “starvation” methods.

Due to the tube now running at such a reduced supply level, the anode current is much, 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.

Therefore both these points combined means that we have a usable tube circuit running off a battery power supply – battery life is approximately 16 hours from 4 x AA size batteries – but also the tube runs a lot cooler – hence the name “COOLTRON”!

Mode d'emploi de l'utilisateur

Merci d’ajouter la pédale COOLTRON VOX Bulldog Distortion/Big Ben Over- drive/Brit Booster à votre arsenal sonore. Notre objectif principal est de vous fournir les produits aux sonorités les meilleures, où que vous vous trouviez, et nous sommes certains que vous utiliserez ces pédales avec autant de plaisir que nous avons eu à les concevoir.

Bedienungsanleitung

Herzlichen Glückwunsch zum Hinzufügen des VOX COOLTRON Bulldog Dis- tortion/Big Ben Overdrive/Brit Booster Pedal zu Ihrer Anlage. Unser größtes Ziel ist es,Ihnen über die klangreichsten Produkte zu bieten, und wir glauben, dass Sie mit diesen Pedalen so viel Spaß haben werden wie wir bei deren Entwurf!

Manual del usuario

Gracias por la compra del pedal Vox COOLTRON Bulldog Distortion / Big Ben Overdrive / Brit Booster. Nuestra intención es ofrecerte los productos con el mejor sonido y creemos que los disfrutarás tanto como hemos disfrutado nosotros diseñándolos.

© 2004 VOX AMPLICATION LTD.

Printed in Japan

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Vox Cooltron owner manual What is COOLTRON?, Basic Operation, G S
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Cooltron specifications

Vox Cooltron represents a cutting-edge advancement in guitar amplification technology, promising musicians enhanced sound quality, versatility, and ease of use. Designed to meet the needs of both amateur and professional guitarists, the Cooltron series showcases a sleek aesthetic and a host of impressive features tailored for modern performances.

One of the main highlights of the Vox Cooltron line is its innovative tube technology. While traditional amplifiers may rely solely on solid-state components, the Cooltron amps incorporate hybrid systems that combine both valves and solid-state circuitry. This unique approach delivers classic tube warmth while ensuring reliability and consistency during performances. The result is an enriched tonal palette that captures the essence of vintage sounds while offering the precision demanded by contemporary musicians.

Moreover, the Cooltron amps are equipped with Vox’s proprietary “Tone Control” system, allowing players to shape their sound effectively. This system features multiple channels with adjustable EQ settings, reverb, and effects that cater to a variety of genres, from blues and rock to metal and jazz. Musicians can achieve everything from crisp clean tones to saturated overdrives, making the Cooltron an incredibly versatile tool in any guitarist's arsenal.

The user interface of the Vox Cooltron is intuitive and straightforward, ensuring that players can quickly dial in their preferred settings without unnecessary distractions. Its compact design makes it an ideal choice for gigging musicians and home studio enthusiasts alike, delivering powerful sound in a portable package.

Another standout characteristic of the Cooltron amplifiers is their construction quality. Built with durability in mind, they feature robust casings and high-quality components that can withstand the rigors of travel and performances. This rugged design ensures that the amp maintains its performance over time, providing reliability night after night.

In addition to sound quality and durability, the Vox Cooltron's aesthetic appeal cannot be overlooked. The modern yet timeless design features elegant finishes and visually striking dials, making it an attractive addition to any stage setup.

In summary, Vox Cooltron amplifiers combine innovative tube technology, versatile tone shaping, intuitive controls, and rugged construction, making them a favorite among guitarists seeking top-tier sound quality and performance. With the Cooltron series, Vox continues its legacy of excellence, providing musicians with the tools they need to express their creativity fully.
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