User manual MARSHALL VBA 400 VALVE BASS AMPLIFIER

[. . . ] VBA 400 VALVE BASS AMPLIFIER ENGLISH From the Chairman I would like to personally thank you for selecting our VBA400 valve bass head. Since I started Marshall Amplification in 1962 I have witnessed some incredible breakthroughs and advances in amplifier design technology, however there is an inescapable magical tone that comes from using a traditional Marshall valve amplifier. Furthermore it is a tone that is just as valid and just as much sought after today as it was all those years ago when I had my first shop in Hanwell, London. What time and progress has given us is the ability to make valve amps that are more versatile. [. . . ] On switching off, the Standby should always be switched before the Power Switch. The standby facility is particularly useful live, between sets, as it allows you to reduce the amount of heat generated by the amplifier but keep the valves operating, which is conducive to longevity of valve life. Valve life can be further increased by always ensuring that the amplifier is allowed to cool down completely after use and before transportation. 6. Treble Controls the high frequencies of the bass guitar tone, making your sound brighter when increased. 7. Middle Dictates the middle register of the amplifier. Turning this up will make your bass sound fatter. Conversely reducing the amount of middle in your tone will result in a sharper sound. Introduction VBA stands for Valve Bass Amplifier and who better to make a bass amp powered by valve technology than Marshall Amplification?Over 36 years of designing and manufacturing world renowned high quality valve amps has given us priceless knowledge, experience and insight in the world of valve tone. The VBA400 gives you 400 Watts of Marshall valve power courtesy of 12 valves; 8 6550 power valves, 3 ECC83 classic Marshall pre-amp valves and 1 ECC82 valve. In addition to great tone, the VBA400 combines a number of other exciting and useful features. Situated on the rear panel of the amp is a Tuner Output which allows you to keep a tuner in line at all times (the bass is still plugged into the input on the front panel). Should you want to tune up during a live situation in silence, simply press the Tuner Mute facility button and both the sound to your speakers and to the DI will be cut off. All valve amps need to be connected to a speaker before use and failure to do so will result in serious damage to the amp. To ensure that you do not damage your VBA400 by inadvertently forgetting to plug your amp into a speaker, we have designed the unit so that power cannot be applied internally unless it is connected to a speaker. The VBA400 also features an instant overall tonal re-shaper in the form of a Contour control which has three pre-sets to allow you to dial in three different characters in an instant. 8. Contour 3 position control adjusting the overall tonal voicing of the amplifier. Position 1 tailors the response of the amplifier for smooth low end, restrained lower mids, and mild high end lift, to give the classic vintage valve bass tone. In position 2 the lower mid is made more prominent whilst simultaneously the upper mids are subtly scooped to give a more aggressive, growling quality to the amplifier's tone. Position 3 introduces a gentle overall mid boost for an immediate, cutting, `in your face' tone. 3. Master Volume Governs the overall volume of the VBA400. 4. Deep The Deep Switch adds a tuned or resonant bass boost to your sound, increasing bottom end thud, without making your tone woolly around the bottom end. 9. Bass Controls the amount of low frequencies or bottom end in your tone. 2 3 ENGLISH ENGLISH 10. [. . . ] Signs that the valves are nearing the end of their useful operating life include loss of perceived output power, increase in valve microphony (detectable as a background `ringing' type noise) and deterioration in tone. When the time comes to fit new valves it is strongly recommended that only Marshall replacement valves, tested to the same specification as the originals, be used, and that these are installed by an approved Marshall service agent who has access to the measuring equipment required to set the internal bias and balance controls to optimally suit the new valves being fitted. 3. Return For connection to the output of an external effects processor. 4. Normal / Earth Lift Linking one piece of earthed electrical equipment to another earthed piece of electrical equipment can result in an audible hum, due to the formation of an earth loop. [. . . ]