Marshall
From GuitarWiki
Marshall Amplification is a British company which designs and manufactures electric guitar amplifiers. Marshall amplifiers are well known and highly popular among guitarists. The sight and sound of a Marshall stack amp with a Gibson Les Paul or Fender Stratocaster is an iconic image in pop-cuture. To this day, top-line Marshall amplifiers still use valve preamp and poweramp stages instead of solid-state devices (transistors), although Marshall also manufactures cheaper solid-state or hybrid devices. Vacuum tube amplifiers (known as "valve amplifiers" in the UK) are generally considered to exhibit a "warmer" tone than that of transistors, particularly when overdriven; instead of abruptly clipping off the signal at cut-off and saturation levels, the signal is smoothly rounded off. Vacuum tubes also exhibit different harmonic effects than transistors (see tube sound for more about the sonic differences between transitors and vacuum tubes). Though technology continues to change, the most sought after, best sounding, and most expensive amps use technology that is considered quite obsolete. The sound of a Marshall Plexi or JCM800 amp is among the most recognized in popular music, and there is a constant demand for both cutting edge and vintage amplifiers.
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History
Marshall Amplification was first founded during the early 1960s by Jim Marshall in a small shop in London. Initial products were 45 watt amplifiers, very similar in both design and tone to Fender products of the day. The first Marshall amplifier built was based on the Fender Bassman, which was Jim Marshall's favorite amplifier. Instead of using four 10 inch Jensen speakers in an open back cabinet as in the Bassman, Marshall used four 12 inch Celestion speakers in a closed back cabinet that produced a fuller and more aggressive sound. Early customers included Pete Townshend and John Entwistle of The Who, whose search for extra volume led Marshall to design the classic 100 watt valve amplifier. Additionally, a switch to the European EL34 poweramp valve increased the product's potential for overdrive. Marshall's profile was further raised by one of the amplifiers appearing on the cover of the John Mayall's Bluesbreakers LP which featured Eric Clapton. As the 1960s drew to a close, the overdriven tone of the Marshall was further exploited by guitarists such as Clapton, Jimi Hendrix, and Jimmy Page. Amplifiers from this era, known as "plexis" because of their plexiglas front panel, now have significant collector value and can command high prices.
Amplifiers from the 1970s onwards can be distinguished most easily by their brushed metal front panel. In the mid-1970s, Marshall introduced the "master volume" series - these amplifiers claimed to offer the overdriven tone of the earlier products, but at a much lower volume. This design was the idea of Tony Frank of Unicord in Westbury, NY, Marshall's American distributor. This was achieved by limiting the output of the tube preamp stage; unfortunately, this results in a less pleasing overdriven tone, as much of the smooth, singing sustain of a classic valve amplifier comes from the poweramp tubes. Marshall continued to offer the earlier models, but many players agree that earlier amplifiers are still better. In 2004 Marshall started selling hand-wired amplifiers based on models built in the 1960s, including the 18-watt combo, 20-watt head and cabinet, and 100-watt Super Lead, all of which are faithful recreations of the originals.
Per Rick Reinckens, who was told by Frank Kosinsky, Unicord's Chief Engineer in the late 1970s, Marshalls were distributed in the U.K. in the 1970s with all-European tubes, including KT-66 output tubes. Unicord felt they could barely push the rated output, so for American models Unicord substituted 6550 industrial tubes. The 6550's easily output the rated power but Unicord was concerned that the original output transformers could not handle full output on a sustained basis, so Unicord, which began as a transformer manufacturer, redesigned the output transformer for units distributed in the U.S. Subsequently, U.K. Marshall adopted the new design for all models.
Marshall is known for its mid-range tone control, which was rare in the 1970s and earlier. Per Kosinsky, the design called for a 20k potentiometer, which was difficult to find in Britain back then. 5k potentiometers were routinely substituted; the result was that the mid-range control could easily "kill" the highs too. Units sold to well-known guitarists were corrected before shipment. Also many name guitarists had the tone control circuits customized.
Through the 1980s and 1990s, Marshall continued to introduce new series of amplifiers which offered more gain and overdrive at low volumes - successively, the JCM800 (enormously popular with hard rock and metal acts), JCM900 and JCM2000 series. Marshall continues to hold a leading position in the market, as many competitors (for example, Hiwatt, Sound City, Vox and Orange) either amalgamated or disappeared in the 1970s.
Marshalls recent Valvestate amplfiers are seen as revolutionary as they contain a hybrid of valve technology and solid state technology. Currently named the "AVT series" there is a huge range of models, all of which are cheaper than their all valve counterparts. Many guitar magazines gave the technology well received reviews due to its great tonality yet low price. The single valve featured in the valvstate amps can last from 2 years to 3 with standard use.
Marshall Stack
The classic Marshall stack is a symbol of loud rock music. A full stack consists of one head containing the actual amplifier on top of two stacked 4x12s, which are loudspeaker cabinets each containing four 12 inch loudspeakers arranged in a square layout. The top cabinet has the top two loudspeakers angled slightly upwards, giving the Marshall stack a distinctive appearance. When a single cabinet is used, the complete unit is called a half stack.
It is claimed that the full stack was invented by Pete Townshend, for whom Marshall built a huge speaker cabinet containing eight 12 inch speaker in the mid-1960s, to compete with the volume of John Entwistle and Keith Moon. Townshend loved the cabinet, but it was too heavy to transport; he took it back to Marshall and Jim Marshall came up with the idea of cutting it in half. Thus the stack was born.
Marshall also produces 'combo' amplifiers which combine speaker and amp in one case and several variations of the classic stack design including a mini stack and a micro stack, which is about 10 inches high and runs on batteries.
For even greater power, a second or even a third 'slave' head can be driven from the master amplifier, each additional amplifier head driving another two cabinets. This was taken to its logical conclusion in the early 1970s by the band Blue Öyster Cult, who used an entire wall of full-stack Marshall amplifiers as their backdrop. Slash of Guns N' Roses had used Marshall amplifiers. Bands such as Slayer and Yngwie Malmsteen also use walls of Marshalls. Both Kerry King and Jeff Hanneman can be seen playing in front of a total of 24 cabinets, and Yngwie has used as many as 31. Although it is likely that these are "dummy Cabs", which are onstage stage for visual effect and not actually used. It is likely that maybe only 2 or 4 cabs are actually powered, as using this many could cause serious problems with the overall mix of a live show.
Trivia
- Marshall is based in Bletchley, Milton Keynes. It is currently the shirt sponsor of Milton Keynes Dons F.C.
- Marshall produced the amplifier with a volume dial that went up to 11, for the spoof 'rockumentary' This is Spinal Tap.
