Musical instrument manufacturing
|Founded||London, England (1962)|
|Headquarters||Bletchley, Milton Keynes, England|
|Area served||United Kingdom, United States|
Marshall Amplification is a British company that designs and manufactures music amplifiers, speaker cabinets, brands personal headphones/earphones (made by Zound Industries), and, having acquired Natal Drums, drums and bongos. It was founded by drum shop owner and drummer Jim Marshall, and is now based in Bletchley, Milton Keynes.
Marshall's guitar amplifiers are among the most recognised brands in amplification. They are known for their own specific sound (the Marshall "crunch"). This signature sound was due to a long period of time of guitarists coming into Marshall's drum shop, and complaining about the amps currently on the market not having the right sound. After gaining a lot of publicity, they were sought out by guitarists for this new sound, as well as the increased volume of Marshall amps compared to the amps that were being sold then. Many of the current (and reissue) models of guitar amplifier continue to use vacuum tubes, as is common in this market sector. Marshall also manufactures less expensive solid-state and hybrid equipment.
- 1 History
- 2 Birth of the Bluesbreaker, the Plexi, and the Marshall stack
- 3 Mid-1970s and 1980s
- 4 Current models
- 5 The Marshall Legacy
- 6 Sponsorships
- 7 See also
- 8 References
- 9 External links
After a successful career as a drummer and teacher of drum technique, Jim Marshall first went into business in 1962 with a small shop in Hanwell, London, selling drums, cymbals and drum-related accessories; Marshall himself also gave drum lessons. According to Jim, Ritchie Blackmore, Big Jim Sullivan, and Pete Townshend were the three main guitarists who often came into the shop and pushed Marshall to make guitar amplifiers and told him the sound and design they wanted. Marshall Ltd. then expanded, hired designers and started making guitar amplifiers to compete with existing amplifiers, the most notable of which at the time were the Fender amplifiers imported from America. These were very popular with guitarists and bass players, but were very expensive. The three guitarists were among the first customers of the first 23 Marshall Amplifiers made.
First amplifiers: birth of the JTM 45
Jim Marshall thought he could produce a cheaper alternative to American-made guitar amplifiers, but he had limited experience as an electrical engineer. He enlisted the help of his shop repairman Ken Bran and an EMI technician named Dudley Craven, and between them they decided they most liked the sound of the 4x10" Fender Bassman. They made several prototypes using the Fender Bassman amp as a model. The sixth prototype produced, in Jim's words, the "Marshall Sound".
The first few production units almost copied the Bassman circuit, with American military surplus 5881 power valves, a relative of the 6L6. Few speakers were then able to handle more than 15 watts, which meant that an amplifier approaching 50 watts had to use four speakers. For their Bassman, Fender used four Jensen speakers in the same cabinet as the amplifier, but Marshall chose to separate the amplifier from the speakers, and placed four 12-inch Celestion speakers in a separate closed-back cabinet instead of the four 10-inch Jensens in an open-back combo. Other crucial differences were the use of higher-gain ECC83 valves throughout the preamp, and the introduction of a capacitor/resistor filter after the volume control. These circuit changes gave the amp more gain so that it broke into overdrive sooner on the volume control than the Bassman, and boosted the treble frequencies. This new amplifier, tentatively called the "Mark II", was eventually named the "JTM 45", after Jim and his son Terry Marshall and the max. wattage of the amplifier.
Marshall entered into a 15-year distribution deal with British company Rose-Morris during 1965, which gave him the capital to expand his manufacturing operations, though it would prove to be costly. In retrospect, Marshall admitted the Rose-Morris deal was "the biggest mistake I ever made. Rose-Morris hadn't a clue, really. For export, they added 55% onto my price, which pretty much priced us out of the world market for a long time."
The new contract had disenfranchised several of Marshall's former distributors, among them his old friend Johnny Jones. Marshall's contract did not prevent him from building amplifiers outside the company, and so Marshall launched the Park brand name, inspired by the maiden name of Jones's wife.
Starting in early 1965, Park produced a number of amplifiers including a 45 watt head. Most of these had Marshall layout and components, though some unusual amplifiers were made, such as a 75 watt keyboard amplifier with KT88 tubes. A 2x12" combo had the option of sending the first channel into the second, probably inspired by Marshall users doing the same trick with a jumper cable.
In 1982, Park came to an end, though Marshall later revived the brand for some transistor amplifiers made in the Far East.
Other Marshall brand names
Other brand names Marshall Amplification had used for various business reasons included Big M (for the then-West German market), Kitchen/Marshall (for the Kitchen Music retail chain in North London), Narb (Ken Bran's surname spelled backwards) and CMI (Cleartone Musical Instruments). Amplifiers sold under these brand names are quite rare, and sell to collectors at high prices.
Birth of the Bluesbreaker, the Plexi, and the Marshall stack
To reduce costs Marshall started sourcing parts from the UK. This led to the use of Dagnall and Drake-made transformers, and a switch to the KT66 valve instead of the 6L6 tube commonly used in the United States. The changes gave Marshall amplifiers a more aggressive voice, which quickly found favour with players such as Eric Clapton, who would sit in Jim's shop practising. Clapton asked Jim Marshall to produce a combo amp with tremolo, which would fit in the boot of his car, and one of the most famous Marshall amps was born, the "Bluesbreaker" amp. This is the amplifier, in tandem with his 1960 Gibson Les Paul Standard (the "Beano"), that gave Clapton that famous tone on the John Mayall & the Bluesbreakers' Beano (1966) album.
Other 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. Ken Bran and Dudley Craven, Marshall's developers, doubled the number of output valves, added a larger power transformer and an extra output transformer. Four of these amplifiers were built and delivered to Pete Townshend, and the Marshall Super Lead Model 1959, the original Plexi, was born in 1965. At the request of Pete Townshend, Marshall produced an 8x12" cabinet (soon replaced by a pair of 4x12" cabinets) on top of which the 1959 was placed, giving rise to the Marshall stack, an iconic image for rock and roll. The size of the wall of Marshall stacks "soon became an indicator of the band's status", even when rendered obsolete by improved PA systems; indeed, many of the "ridiculously huge arrays of heads and cabs" included dummies. Still, most 100-watt heads made today, even though they often contain many more features (or different tubes, such as the more American-sounding 6L6 tubes), "have their roots in Marshall's groundbreaking design".
Another valve change
At this time, the KT66 valve was becoming more expensive, as the M-OV Company faced greater competition from Mullard. Hence, another valve change was made, with Marshall starting to use European-made Mullard EL34 power stage valves. These have a different overdrive character than the KT66s, which gave Marshalls a more aggressive voice still. In 1966, a young Jimi Hendrix was in Jim's shop, trying the amplifiers and guitars. Jim Marshall expected Hendrix to be "another American wanting something for nothing" but to his surprise, Hendrix offered to buy the amplifiers outright at retail price, if Jim would provide him with support for them around the world. Jim Marshall agreed, and several of Hendrix's road crew were trained in the repair and maintenance of the Marshall amps through the years.
The amplifiers from this era are easily identifiable by their acrylic glass (a.k.a. Plexiglas) front panel, which earned them the nickname "Plexi". These now have significant collectors' value. In 1967 Marshall released a 50 watt version of the 100 watt Superlead known as the 1987 Model. These were also called 50 watt Plexi's. The amplifiers from the 1970s onwards can be distinguished most easily by their brushed metal front panel. After 1973, to streamline production, labour-intensive handwiring was discontinued and Marshall valve amplifiers were switched to printed-circuit-board (PCBs). Much of the debate about the difference in tone between the plexi- and aluminium-panel Marshall amps comes from the fact that in 1974 Marshall's US distributor had them change all of the amps sold in the US and Japan over to the much more rugged Tung-Sol 6550 instead of the EL34 output tube, with a different sound.
Mid-1970s and 1980s
In the mid-1970s, Marshall introduced the "master volume" ("MV") series, which was initially called the "JMP" ("Jim Marshall Products"). This was in response to the demand for yet more distortion, and many techs had been modifying the amps for years by connecting the two input stages in series rather than parallel as in the original Marshalls. A master volume was introduced to make the volume levels more manageable. Per Rick Reinckens, who was a short-term Unicord employee electronic technician who tested the first units when they arrived from England, Tony Frank, Unicord's chief design engineer, came up with the dual-volume-control idea. This gave the new breed of Marshalls a different voice, more cutting and edgy, which later found favour with players such as Randy Rhoads, Zakk Wylde and Slash. The 1959 and 1987 non-master volume models also continued under the JMP line, but their voicing became slightly harder/brighter during the 1970s.
Soon after the Rose-Morris deal had ended in late 1980, Marshall repackaged two MV models, the 2203 and the 2204 (at 100 and 50 watts, respectively), along with the 1959 and 1987 non-master volume Super Lead in a new box with a new panel, and called it the "JCM800" series (named after his initials and the registration plate of his car). Marshall made several amplifiers under the JCM800 name.
Because the valve industry had begun to fade and Marshall became worried that the standard power valve, the venerable EL34, would soon become unavailable, a number of JCM 800s were factory equipped with the 6550 beam pentode power valve, a valve with a different tonal character, which not all users loved. Marshall would not return to full-time use of the EL34 in all of its valve amps until the rise of vacuum tube factories in the mid and late 1990s when former Soviet countries made most valve types plentiful again.
A landmark year for Jim Marshall was 1987. It marked 25 years in the amplifier business and 50 years in music. This was celebrated with the release of the Silver Jubilee series of amps. The Silver Jubilee series consisted of the 2555 (100 watt head), 2550 (50 watt head) along with other 255x model numbers denominating various combos and even a "short head". The Jubilee amps were heavily based on the JCM800s of the time, featuring a very similar output section along with a new preamp. Their most publicised feature was the half-power switching, which is activated by a third rocker switch next to the standard "power" and "standby" switches. On the 50 watt model this was reflected in the numbering – 2550 is switchable from 25 to 50 watts – and also reflected Marshall amps' 25th anniversary and Jim Marshall's 50 years in music. The amps were trimmed in silver covering, and had a bright silver-coloured faceplate, along with a commemorative plaque.
The Jubilee also featured a "semi-split channel" design, in which two different input gain levels could be set, running through the same tone stack and master volume control. This allowed for a "classic Marshall" level of gain to be footswitched up to a modern, medium to high gain sound, slightly darker and higher in gain than the brasher JCM800 sound that typified 1980s rock music. "The sound of these amps is particularly thick and dark, even on the Marshall scale of things. The gain by today's standards is medium." The distortion sound of the Jubilee range is typified by Slash's live work with Guns N' Roses. He rarely used anything else live, but oddly the Jubilee did not appear on any Guns N' Roses studio albums – instead these feature modded JCM800s. It can be heard on some of the Velvet Revolver material though. The Jubilee amps also featured a "pull out" knob that activated a diode clipping circuit (similar to boosting the amp's input with an overdrive pedal). Other notable Jubilee users include the Black Crowes and John Frusciante (Red Hot Chili Peppers).
After the Jubilee year, production of the 25xx series amplifiers continued for one more year (with no internal changes), but reverted to a standard Marshall livery of black and gold. These are sometimes referred to as the JCM800 Custom amplifiers.
Competition from American amplifier companies
Marshall began to see more competition from American amplifier companies such as Mesa Boogie and Soldano. Marshall then updated the JCM800 range with additional models and new features such as "channel switching", which meant that players could switch between clean and distorted tones with the push of a foot-operated switch. This feature debuted in the 2205 (50 watt) and 2210 (100 watt) series and these amps contained more pre-amp gain than ever thanks to a new innovation; diode clipping. This meant a solid-state diode added additional distortion to the signal path, akin to adding a distortion pedal. As such the split channel JCM800s were the highest gain Marshalls yet built – "When they were first released, many players were shocked (some were even put off) by it's bright, intense distortion – far more than any other amp of the day." While hotly criticised today among valve purists, these amps were more popular than ever, finding mass acceptance within the hard rock community and still in use today by many. The split-channel JCM800s are still used by Tom Morello (Rage Against the Machine, Audioslave) and were played exclusively by Michael Schenker (Scorpions) for many years.
Marshall around this time began further experiments with solid-state amplifiers, which were increasingly improving in quality due to technological innovations but were still considered beginner level equipment. Regardless, solid-state product lines with the Marshall name on them were and still are a wild (if critically discounted) success for the company, allowing entry level guitarists to play the same brand of amp as their heroes. One particularly successful entry-level solid-state Marshall was the Lead 12/Reverb 12 combo series, which featured a preamp section very similar to a JCM800, and a particularly sweet-sounding output section. These amps were actually used on record by Billy Gibbons of ZZ Top, and are now in some demand.
In the 1990s, Marshall updated its product line again with the JCM900 series. Reviewed by Guitarist magazine in the UK and given the line, "Shredders, here is an amp you won't need to have modified", this move by Marshall was again an outgrowth of musicians' desires, featuring more distortion than ever and retaining popular aspects of the late JCM800 models. However, despite such marketing claims they were not as hi-gain as advertised and lacked a full gain stage. Marshall rectified this with the SL-X series (as used by Tom Johnson of Darkhorse or the group Kiss). This model was one channel and was given an additional pre-amp ECC83/12AX7 instead of diode-based distortion. Still, if not for shredders, the JCM900 was well received by younger players associated with pop, rock, punk and grunge which was widespread by the early 1990s. The Dual Reverb was also notably used by Dave Navarro.
The early JCM900 range featured the 4100 (a split channel, dual reverb head descended from the 2210), and the 4500 (same in a 50 watt configuration), along with the usual range of combos along the same lines. It also featured a single-channel descendant of the 2203/2204 line (the 2100 or 2500 Mark III), which is now quite rare and was essentially replaced by the SL-X (2100 or 2500 Mark IV) in the early 1990s – itself quite rare in EL34 form. Although the EL34 had at this time begun to return to prominence, a number of these were shipped with 5881 valves, a now uncommon valve similar in tone and build to a 6L6. Most of the JCM900s and 6100s built between 1994–1998 left the factory with the 5881s.
Around this time, Marshall released a few "special edition" amps in this range, including a "Slash Signature" model, a first for the company. This was actually a re-release of the earlier Silver Jubilee 2555 amplifier, with identical internals, a standard Marshall look, and a Slash logo. This amp retained EL34s and was produced 3,000 units from 1996 to 1997.
1992 marked 30 years in the amplifier business. To commemorate this milestone, Marshall released the 30th Anniversary series of amplifiers, the EL34 powered 6100LE with commemorative blue covering and gold faceplate, which was followed by the 6100 (in standard Marshall livery and still EL34 powered) and then in 1994 the 6100LM (in standard Marshall livery but now 5881 powered like the JCM900s of the time). All versions of the 6100 had three channels; clean, crunch and lead. The clean channel featured a mid shift, which gave the option of a more "Fender-like" voicing, and the crunch channel featured three modes recreating all the classic Marshall crunch tones of the past three decades. The lead channel featured a switchable gain boost and a mid-range contour switch, which gave it the tone and gain levels, which Marshall's engineers hoped would keep it competitive in the high-gain world in the early to mid-1990s. In fact some players felt the lead channel was perhaps the weaker link in the amplifier's arsenal, and it came in for revisions in the third year of production (the LM standing for "Lead Mod"). This revision featured even higher gain.
The Anniversary series found prominence with Joe Satriani in particular, who favoured the early EL34 powered versions and used only the clean channel live along with a modded distortion pedal Boss DS-1. Satriani used these models almost exclusively for live work and on a number of studio albums including The Extremist (1992) until the early 2000s. The Anniversary models were probably the most complicated Marshall ever (other than perhaps the later JVM), with full MIDI control built in, half power switching, pentode/triode switching, adjustable speaker excursion, and a low volume compensation switch. Despite all this complication the amps had a pure signal path that did not share preamp tubes between channels (unlike later Marshall designs like the TSL and JVM). Other famous 6100 users included Alex Lifeson on Rush's album Test for Echo (1996) and Ocean Colour Scene (OCS) guitarist Steve Cradock.
|This section needs additional citations for verification. (October 2009)|
Marshall currently produces a number of amplifiers, which are a mix of modern designs and vintage reissues. Most models attempt to include the "classic" Marshall "roar".
As of 2012[update] Marshall produced a wide range of amps with the look and sound of the Marshall valve amp. The longest running of such models is the JCM2000 range, which is split into the two- and three-channel series, known as the Dual and Triple Super Leads. These amps are a continuation of the JCM800 and 900 series, although the controversial diode clipping circuit used in the later 800 and 900 amps has been removed in favour of additional valve gain stages. Although lumped together as JCM2000 models the DSL and the TSL have different circuits and are more distantly related than the model range suggests. The DSL is an extension of the JCM800 series with several changes including dual reverb controls.
Marshall looked towards a new flagship, the JVM, made in a variety of models and ranges. These amps have up to four channels, each with three-foot-switchable modes, dual master volumes, reverb controls for each channel, and a foot-switchable effects loop. These features can be programmed into the standard foot-switch to be foot-switchable as "patches", so now the user can switch from, say, a clean channel with a chorus in the effects loop and reverb, to a medium-gain rhythm sound with no effects, to a high-gain lead sound with boosted output volume, with one click of the foot-switch per sound. The JVM range consists of a 100-watt four-channel head (JVM 410H ), JVM 410C (2x12" speaker combo), a 100-watt two-channel head (JVM 210H, used by Joe Satriani for some time), JVM 210C (2x12" speaker combo) and 50-watt versions of these (JVM 205H (head), JVM215C (1x12" speaker combo) and JVM205C (2x12" speaker combo), respectively).
Around the same time as the release of the JVM, Marshall also released an amp called the Vintage Modern, which is designed to be much simpler, with a single channel and designed to be controlled more by the player's style and guitar than by channel switching or multiple settings, reminiscent of the vintage "Plexi" and JCM800 range, but with modern conveniences such as foot-switchable dynamic ranges (distortion levels), effects loop and reverb. The Vintage Modern series consists of the 2466 100-watt head and 2266 50-watt head with matching combos and a matching cabinet loaded with G12C 25-watt Greenbacks. The Vintage Modern is the first Marshall since the late 1960s to be powered by KT66s, a European version of the 6L6 tube.
In 2001 Marshall reissued many of its earlier amplifiers, such as the Model 1959-SLP, which is designed to be a reissue of the late 1960s era "Plexi" amplifier, but which are in reality reissues of the post-1973 Super Lead models in that they use printed circuit boards internally to reduce manufacturing cost. The original design utilised hand-wired circuits on turret boards, which is now available for a premium in the "hand-wired" series. Other reissues are similarly PCB designed, even where the originals were hand-wired, except where explicitly noted (i.e. the "hand-wired" range currently offered).
Marshall's "Valvestate" amplifiers contained a hybrid of valve and solid-state technology. Currently named the "AVT series" (although these are now out of production, being replaced with the "AVT tribute" for a short time), there are a number of different models, all of which are less expensive than their all-valve counterparts. It is Marshall's current line of "hybrid" amplifier, featuring a 12AX7 preamp tube employed in the preamp (to "warm up" the signal) as well as solid-state components, with a solid-state power amp. These are considered and marketed as intermediate-level equipment to bridge the gap between the higher valve range and lower range MG series.
In January 2009 Marshall released their latest variant of the MG line of practice amplifiers. Replacing the MG3 line, the MG4 has been designed to offer the guitarist a whole host of features whilst keeping the control of the amplifier simple.
Marshall currently manufactures a professional, all-valve bass rig called the VBA400. It houses eight 6550 power valves plus three ECC83 and one ECC82 preamp valves. The input accommodates both active and passive bass pick-ups; there is also an XLR DI output for recording complete with Earth (grounding) lift and Pre/Post EQ switches.
There are also solid-state models called MB series ranging from 15 watts to 450 watts and extension cabinets.
Model number confusion
Occasionally confusion has arisen due to Marshall's method of naming each amp model, especially during its first few decades, when it was distributed under Rose-Morris. Early Amplifier models were simply named after their catalogue number, so for example the 1962 blues breaker was item one thousand nine hundred and seventy two in the Rose-Morris catalogue. Later amplifiers were given range designations as well as model numbers, which often indicated information about the amplifier itself, for example the JCM2000 range of amplifiers had models such as the TSL100 (Triple Super Lead 100 W) and combo amplifiers like the TSL212 (Triple Super Lead with 2x12" Celestion speakers) other product ranges use similar descriptive model numbers. Often Speaker cabinets designed to suit a particular range will be give a prefix before the speaker description such as JVMC212 (JVM cabinet 2 x 12" Celestion speakers) or a suffix C to denote a combo variant of an amplifier such as the Vintage Modern 2266C (Vintage Modern 2 channel 2 x KT66 valves Combo).
The Marshall Legacy
The classic Marshall 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.
In the early-mid-1960s, Pete Townshend and John Entwistle of The Who were directly responsible for the creation and widespread use of stacked Marshall cabinets. Pete later remarked that John started using Marshall Stacks to hear himself over Keith Moon's drums and Townshend himself also had to use them just to be heard over John. In fact, the very first 100 watt Marshall amps were created specifically for Entwistle and Townshend when they were looking to replace some equipment that had been stolen from them. They approached Jim Marshall asking, if it would be possible for him to make their new rigs more powerful than those they had lost, to which they were told that the cabinets would have to double in size. They agreed and six rigs of this prototype were manufactured, of which two each were given to Townshend and Entwistle and one each to Ronnie Lane and Steve Marriott of The Small Faces. These new "double" cabinets (each containing 8 speakers) proved too heavy and awkward to be transported practically, so The Who returned to Marshall asking if they could be cut in half and stacked, and although the double cabinets were left intact, the existing single cabinet models (each containing 4 speakers) were modified for stacking, which has become the norm for years to follow.
Entwistle and Townshend both continued expanding and experimenting with their rigs, until (at a time when most bands still used 50 to 100 W amps with single cabinets) they were both using twin stacks, with each stack powered by new experimental prototype 200 W amps, each connected to the guitar via a Y-splitter. This, in turn, also had a strong influence on the band's contemporaries at the time, with Cream, The Jimi Hendrix Experience and Led Zeppelin following suit. However, due to the cost of transport, The Who could not afford to take their full rigs with them for their earliest overseas tours, thus Cream and Hendrix were the first to be seen to use this setup on a wide scale, particularly in America. Ironically, although The Who pioneered and directly contributed to the development of the "classic" Marshall sound and setup with their equipment being built/tweaked to their personal specifications, they would only use Marshalls for a couple of years before moving on to using Hiwatt equipment. Cream, and particularly Hendrix, would be widely credited with the invention of Marshall Stacks.
The search for volume was taken on its next logical step with the advent of "daisy chaining" two or more amplifiers together. As most amplifier channels have two inputs, the guitar signal being present on both sockets, the cunning musician hooked the spare input of one channel to an input on another amp. By 1969 Hendrix was daisy chaining four stacks, incorporating both Marshall and Sound City amplifiers, as recommended to him by Townshend.
This competition for greater volume and greater extremes was taken even further in the early 1970s by the band Blue Öyster Cult, which used an entire wall of full-stack Marshall amplifiers as their backdrop. (BÖC also referred to Marshalls in the songs "Cities on Flame with Rock and Roll" and "The Marshall Plan"). Artists such as Slayer and Yngwie Malmsteen also use walls of Marshalls; both Kerry King and Jeff Hanneman of Slayer would often be seen playing in front of a total of 24 cabinets. Malmsteen toured with 30 heads and 28 cabinets, and in 2011 said he would use 60 full stacks on his next tour. Many of those cabs used by rock bands, however, are dummies, and many artists who do not even use Marshall amplifiers have the dummy stacks on stage.
- List of guitar amplifier manufacturers
- Fender Musical Instruments Corporation
- Gibson Guitar Corporation
- Mesa Boogie
- Up to eleven
- "The First 30 Years of Amplifiers". Retrieved 31 March 2012.
- Jim Marshall Interview
- Salter, Trent (April/May 2003). "Jim Marshall Interview". Premierguitar.com. Retrieved 10 February 2011.
- History of Marshall from Guitar World Magazine, September 2002, page 84
- Pittman, Aspen (2003). The Tube Amp Book. Hal Leonard. pp. 76–77. ISBN 978-0-87930-767-7.
- History of Marshall from Guitar World Magazine, September 2002, page 86
- Pittmann, Aspen (2003). The Tube Amp Book. Hal Leonard. pp. 72–73. ISBN 978-0-87930-767-7.
- Millard, A.J. (2004). The electric guitar: a history of an American icon. JHU Press. p. 155. ISBN 978-0-8018-7862-6.
- Doyle, Michael (1993). The history of Marshall: the illustrated story of "the sound of rock". Hal Leonard. p. 37. ISBN 1993 Check
- Thompson, Art; Darrin Fox, Dave Hunter, Matt Blackett (January 2013). "Nine 100-Watt Tube Heads". Guitar Player. pp. 102–14.
- Marshall Amps Info & Schematics
- Maloof, Rich (2004). Jim Marshall, father of loud: the story of the man behind the worlds most famous guitar amplifiers. Hal Leonard. pp. 211–14. ISBN 978-0-87930-803-2.
- Nichols, Ritchie Fliegler ; editor, Jon Eiche ; assistant editor, Leslie (1993). Amps! : the other half of rock 'n' roll. Milwaukee, WI: H. Leonard Pub. Corp. p. 47. ISBN 0-7935-2411-3.
- Nichols, Ritchie Fliegler ; editor, Jon Eiche ; assistant editor, Leslie (1993). Amps! : the other half of rock 'n' roll. Milwaukee, WI: H. Leonard Pub. Corp. ISBN 0-7935-2411-3.
- "Marshall JCM 2555 Slash Signature on SlashParadise". www.slashparadise.com. 10 November 2012.
- Signature Series > 1992LEM > Overview
- "MB Series".
- The Who's Marshall History
- An interview with Pete Townshend from Guitarist magazine, August 1994
- Fox, Darrin. "Yngwie Malmsteen: Total Control". Guitar Player. pp. 64–72, 136.
- Marshall backing Lions all the way – Milton Keynes Today
|Wikimedia Commons has media related to Marshall amplifiers.|