Marshall JTM45: Difference between revisions
→History: dubious claim cn |
|||
| Line 4: | Line 4: | ||
The JTM 45 was first built in 1962, handmade in an all-aluminum chassis, by Ken Bran and Dudley Craven. Because of its power, Marshall decided early on to build it as a head, with a separate 4x12" cabinet with [[Celestion]] speakers. The amplifier itself was based on the [[Fender Bassman]]. It uses [[KT66]] [[vacuum tube | vacuum tubes or valves]] (though early versions had used US 5881, a version of the [[6L6]]<ref>{{cite book|last=Hunter|first=Dave|title=Guitar rigs: classic guitar & amp combinations|year=2005|publisher=Hal Leonard|isbn=978-0-87930-851-3|url=http://books.google.com/books?id=p1-kULtG9tgC&pg=PA111|page=111}}</ref>), and [[12AX7]] tubes (known in Britain as [[ECC83]] valves) in the pre-amplification stage.<ref name=pittman/> |
The JTM 45 was first built in 1962, handmade in an all-aluminum chassis, by Ken Bran and Dudley Craven. Because of its power, Marshall decided early on to build it as a head, with a separate 4x12" cabinet with [[Celestion]] speakers. The amplifier itself was based on the [[Fender Bassman]]. It uses [[KT66]] [[vacuum tube | vacuum tubes or valves]] (though early versions had used US 5881, a version of the [[6L6]]<ref>{{cite book|last=Hunter|first=Dave|title=Guitar rigs: classic guitar & amp combinations|year=2005|publisher=Hal Leonard|isbn=978-0-87930-851-3|url=http://books.google.com/books?id=p1-kULtG9tgC&pg=PA111|page=111}}</ref>), and [[12AX7]] tubes (known in Britain as [[ECC83]] valves) in the pre-amplification stage.<ref name=pittman/> |
||
Significant differences between the Bassman and the JTM include the all-aluminum chassis (it is less susceptible to hum than a steel chassis), a 12AX7 valve as the first in the chain (the Bassman has a [[12AY7]]), the Celestion speakers with a closed cabinet (compared to [[Jensen Electronics|Jensen]] speakers in an open-back cabinet) and a modified [[Feedback#Electronic_engineering|feedback circuit]] which affects the harmonics produced by the amplifier. As Ken Bran later said, "The JTM also had different harmonic content, and this was due to the large amount of feedback I had given it."<ref name=doyle>{{cite book|last=Doyle|first=Michael|title=The history of Marshall: the illustrated story of "the sound of rock"|year=1993|publisher=Hal Leonard|isbn=978-0-7935-2509-6|pages=17–22|url=http://books.google.com/books?id=E90tMBs9_FEC&pg=PA21|chapter=The JTM Series 1962-1966}}</ref> The amp was also available as a bass (which lacked a "bright" switch) and a [[Public address|PA]] version.<ref name=doyle/> |
Significant differences between the Bassman and the JTM include the all-aluminum chassis (it is less susceptible to hum than a steel chassis{{cn}}), a 12AX7 valve as the first in the chain (the Bassman has a [[12AY7]]), the Celestion speakers with a closed cabinet (compared to [[Jensen Electronics|Jensen]] speakers in an open-back cabinet) and a modified [[Feedback#Electronic_engineering|feedback circuit]] which affects the harmonics produced by the amplifier. As Ken Bran later said, "The JTM also had different harmonic content, and this was due to the large amount of feedback I had given it."<ref name=doyle>{{cite book|last=Doyle|first=Michael|title=The history of Marshall: the illustrated story of "the sound of rock"|year=1993|publisher=Hal Leonard|isbn=978-0-7935-2509-6|pages=17–22|url=http://books.google.com/books?id=E90tMBs9_FEC&pg=PA21|chapter=The JTM Series 1962-1966}}</ref> The amp was also available as a bass (which lacked a "bright" switch) and a [[Public address|PA]] version.<ref name=doyle/> |
||
By the mid 1960s, the JTM 45 had become so popular that it began to supplant the ubiquitous Vox amps.<ref>{{cite book|last=Hunter|first=Dave|title=Guitar rigs: classic guitar & amp combinations|year=2005|publisher=Hal Leonard|isbn=978-0-87930-851-3|page=102}}</ref> |
By the mid 1960s, the JTM 45 had become so popular that it began to supplant the ubiquitous Vox amps.<ref>{{cite book|last=Hunter|first=Dave|title=Guitar rigs: classic guitar & amp combinations|year=2005|publisher=Hal Leonard|isbn=978-0-87930-851-3|page=102}}</ref> |
||
Revision as of 09:20, 21 November 2012
The Marshall JTM 45 is the first guitar amplifier made by Marshall. First produced in 1962, it has been called a "seminal" amplifier,[1] and is praised as the most desirable of all the company's amplifiers.[2]
History
The JTM 45 was first built in 1962, handmade in an all-aluminum chassis, by Ken Bran and Dudley Craven. Because of its power, Marshall decided early on to build it as a head, with a separate 4x12" cabinet with Celestion speakers. The amplifier itself was based on the Fender Bassman. It uses KT66 vacuum tubes or valves (though early versions had used US 5881, a version of the 6L6[3]), and 12AX7 tubes (known in Britain as ECC83 valves) in the pre-amplification stage.[2]
Significant differences between the Bassman and the JTM include the all-aluminum chassis (it is less susceptible to hum than a steel chassis[citation needed]), a 12AX7 valve as the first in the chain (the Bassman has a 12AY7), the Celestion speakers with a closed cabinet (compared to Jensen speakers in an open-back cabinet) and a modified feedback circuit which affects the harmonics produced by the amplifier. As Ken Bran later said, "The JTM also had different harmonic content, and this was due to the large amount of feedback I had given it."[4] The amp was also available as a bass (which lacked a "bright" switch) and a PA version.[4]
By the mid 1960s, the JTM 45 had become so popular that it began to supplant the ubiquitous Vox amps.[5]
In late 1965, Marshall introduced its now standard script lettering, in white, and by early 1966 it began calling the amplifiers "JTM 50".[4] Some 100 early models had red lettering; these are especially collectible.[2] Other cosmetic changes included a gradual switch to different knobs. The JTM 45 became the basis for many subsequent Marshalls, most notably the Bluesbreaker.[6] It ceased being produced in 1966, but was reissued in 1989, though with a modern printed circuit board and 6L6 valves.[4]
Name, numbering
The first JTM 45s did not have the standard Marshall number that later amps had; not until 1965 did the models that derived from the JTM 45 receive numbers.[4]
| Model number | Watts | Dates | Features | Notes |
|---|---|---|---|---|
| - | 30 | 1962-1964 | 2 channels, 4 inputs | Also available in bass and PA versions |
| 1963 | 50 | 1965-1966 | 4 channels, 8 inputs | PA version; "JTM50 MK III" |
| 1985 | 45 | 1965-1966 | 2 channels, 4 inputs | PA version of JTM50 MK II |
| 1986 | 45 | 1965-1966 | High treble and normal channels | Bass version of JTM50 MK II |
| 1987 | 45 | 1965-1966 | High treble and normal channels | Lead version of JTM50 MK II; also with tremolo as Model T1987 |
| 1989 | 45 | 1965-1966 | For electronic organs | Also with tremolo as Model T1989 |
| JTM 45 | 30 | 1989 - | 2 channels, 4 inputs | Reissue of original JTM45 (1987) |
Sound
For all of its differences with the Bassman, the sound of the JTM 45 is still described as "like a tweed Fender"; it has more bass, treble and rectfier tube "sag", and less gain and upper-midrange "punch" than the later, more widely-used Marshall Super Lead. Because of this, it is generally favored more for blues and blues-rock rather than for hard rock.[7]
Notable users
- Angus Young (live, Young has a JTM 45 in an isolation box under the stage)[8][9]
- Gary Moore (reissue)[10]
References
- ^ Hunter, Dave (2005). Guitar rigs: classic guitar & amp combinations. Hal Leonard. p. Back cover. ISBN 978-0-87930-851-3.
- ^ a b c Pittman, Aspen (2003). The Tube Amp Book. Hal Leonard. pp. 66, 68–69. ISBN 978-0-87930-767-7.
- ^ Hunter, Dave (2005). Guitar rigs: classic guitar & amp combinations. Hal Leonard. p. 111. ISBN 978-0-87930-851-3.
- ^ a b c d e Doyle, Michael (1993). "The JTM Series 1962-1966". The history of Marshall: the illustrated story of "the sound of rock". Hal Leonard. pp. 17–22. ISBN 978-0-7935-2509-6.
- ^ Hunter, Dave (2005). Guitar rigs: classic guitar & amp combinations. Hal Leonard. p. 102. ISBN 978-0-87930-851-3.
- ^ Batey, Rick (2003). American Blues Guitar: An Illustrated History. Hal Leonard. p. 106. ISBN 978-0-634-02759-8.
- ^ Hunter, Dave (2005). The guitar amp handbook: understanding tube amplifiers and getting great sounds. Hal Leonard. pp. 75–76. ISBN 978-0-87930-863-6.
- ^ Prown, Pete (2003). Gear Secrets of the Guitar Legends: How to Sound Like Your Favorite Players. Hal Leonard. p. 2. ISBN 978-0-87930-751-6.
{{cite book}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Newquist, H. P. (2004). The hard rock masters. Hal Leonard. pp. 23–24. ISBN 978-0-87930-813-1.
{{cite book}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Prown, Pete (2003). Gear Secrets of the Guitar Legends: How to Sound Like Your Favorite Players. Hal Leonard. p. 10. ISBN 978-0-87930-751-6.
{{cite book}}: Unknown parameter|coauthors=ignored (|author=suggested) (help)