The Marshall JCM800 is a guitar amplifier that is known for doing one thing very well – bright and aggressive distorted guitar tones. Its distinctive and assertive character has formed an integral part of the sound of many rock, metal and punk records since the 1980s.
The JCM800 range of amps was introduced in the early 1980s. These were the first amps produced by Marshall after ending their 15-year distribution deal with retailer Rose Morris and thereby opening themselves up to the market outside of the UK. The name is derived from company founder’s initials and the number, 800, from his car’s license plate at the time.
The JCM800 series followed an almost identical circuit design as the JMP ‘Master Volume’ amps produced in the mid to late ‘70s. These were the first Marshall amps to incorporate a master volume control that enabled the preamp gain to be pushed into heavy distortion while controlling the volume output. This ability to achieve highly distorted guitar sounds at reasonable volume levels attracted rock players and the high gain setting became the signature feature of the amp. Several revisions of the JCM800 were made during the ‘80s, offering both 50w and 100w models as well as adopting features such as dual channels and on-board reverb.
JCM800s models that were exported for sale in the USA were equipped with 6550 output tubes, rather than the standard EL34 configuration. The change in tubes yields a tighter bass response whichis sometimes considered preferential by heavy metal, metal or rock style guitar players. The EL34-powered amps deliver a more pronounced midrange ‘bark’, which is more commonly associated with the ‘classic’ JCM800 sound. It is also not uncommon for users to modify JMC800s from one of these configurations to the other.
The sound of the JCM800 is focused, bright and edgy with a throaty midrange and an unmistakable top end ‘sizzle’. It pairs particularly well with moreharmonically-simple content like power chords and open voicings, making it ideal for rock and metal genres where these feature heavily. It is not uncommon for players in heavier styles of metal to add a ‘boost’ pedal, such as an Ibanez , in front of the amp to yield more gain and tightening of the bottom end.
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