- MARSHALL
- chevron_right ELECTRIC TUBE AMPLIFIERS: BLUESBREAKER SERIES
The Model 1961 and Model 1962 "Bluesbreakers" were the first combo amps produced by Marshall, and according to Jim Marshall were built as a request by Eric Clapton. Two models were designed, and designated the Model 1961 for the 4 X 10 in. and the Model 1962 for the 2 X 12 in. version. The Model 1961 was designed for guitar, to compete with the 4 X 10 in. Fender Bassman, and employed the Marshall Model 1987 lead chassis. The Model 1962 was designed for the bass and guitar and used the Marshall Model 1986 bass chassis. Eric Clapton is known for playing through a second series Model 1962 Bluesbreaker on John Mayall and the Bluesbreakers album, which is where the nickname comes from. Both the Model 1961 and Model 1962 are comprised of two different versions, known as the Series I and Series II and the changes noted below between these two series are the same for both models.
The Series I was produced from late 1964-66 and features the nearly square proportioned and deeper cabinet designed by Jim Marshall. The Series I cabinet included the "White" (thin horizontal gray lines in a white background) grille cloth, changing in 1965 to the classic Gray Bluesbreaker or Pinstripe cloth that featured gray horizontal strips with a subtle snakeskin pattern. The earliest Bluesbreakers employed the gold block Marshall logo, changing around 1965 to the classic Marshall script logo. The Series I was essentially the JTM45 amplifier electronics, combined with multiple speakers in a single Baltic birch cabinet. Utilizing the Radiospares transformers, KT66 power tubes, and GZ34 tube rectification, the amp was rated at 30 to 35 watts. The 2 X 12 Model 1962 combo also included the early G12 Celestion Alnico speakers, which added a violin-like smoothness to the sound.
The Series II was introduced in mid-1965 while the Series I was still in production, and featured a revised cabinet designed by Marshall's chief engineer, Ken Bran. The overall appearance of the Series II cabinet is sleeker than the Series I, and it utilized the classic Marshall Bluesbreaker grille cloth and script logo. During the last six months of 1966, the amps were upgraded to a full 50 watts and were designated the JTM50 MKII (Model 1961) and the JTM50 MKIV (Model 1962). The electronics were revised and employed new EL34 power tubes, Drake transformers, and a solid-state rectifier. They were also equipped with Celestion Greenback Ceramic magnet speakers. During 1968, the physical appearance of the Bluesbreaker was revised with the new full-faced Basketweave grille cloth. Although these amps were still designated as Model 1961 (4 X 10), and Model 1962 (2 X 12), they are not considered the "classic" Bluesbreaker, nor a plexi unit.
Extension cabinets were also available of the Model 1962 (see the Speaker Cabinets section). For a complete history and technical overview of the Marshall Bluesbreaker, please refer to The Marshall Bluesbreaker - The Story of Marshall's First Combo by John R. Wiley. The author would like to thank John R. Wiley for the information in the Bluesbreaker section.
The Series I was produced from late 1964-66 and features the nearly square proportioned and deeper cabinet designed by Jim Marshall. The Series I cabinet included the "White" (thin horizontal gray lines in a white background) grille cloth, changing in 1965 to the classic Gray Bluesbreaker or Pinstripe cloth that featured gray horizontal strips with a subtle snakeskin pattern. The earliest Bluesbreakers employed the gold block Marshall logo, changing around 1965 to the classic Marshall script logo. The Series I was essentially the JTM45 amplifier electronics, combined with multiple speakers in a single Baltic birch cabinet. Utilizing the Radiospares transformers, KT66 power tubes, and GZ34 tube rectification, the amp was rated at 30 to 35 watts. The 2 X 12 Model 1962 combo also included the early G12 Celestion Alnico speakers, which added a violin-like smoothness to the sound.
The Series II was introduced in mid-1965 while the Series I was still in production, and featured a revised cabinet designed by Marshall's chief engineer, Ken Bran. The overall appearance of the Series II cabinet is sleeker than the Series I, and it utilized the classic Marshall Bluesbreaker grille cloth and script logo. During the last six months of 1966, the amps were upgraded to a full 50 watts and were designated the JTM50 MKII (Model 1961) and the JTM50 MKIV (Model 1962). The electronics were revised and employed new EL34 power tubes, Drake transformers, and a solid-state rectifier. They were also equipped with Celestion Greenback Ceramic magnet speakers. During 1968, the physical appearance of the Bluesbreaker was revised with the new full-faced Basketweave grille cloth. Although these amps were still designated as Model 1961 (4 X 10), and Model 1962 (2 X 12), they are not considered the "classic" Bluesbreaker, nor a plexi unit.
Extension cabinets were also available of the Model 1962 (see the Speaker Cabinets section). For a complete history and technical overview of the Marshall Bluesbreaker, please refer to The Marshall Bluesbreaker - The Story of Marshall's First Combo by John R. Wiley. The author would like to thank John R. Wiley for the information in the Bluesbreaker section.
Models (3)
BLUESBREAKER MODEL 1961
View Details
- 30-35W (1964-mid-1966) or 50W (late 1966-1972), 4-10 in. Ceramic magnet speakers, guitar combo, seven-tube chassis (1964-mid-1966) including preamp: 4 X ECC83/12AX7, power: 2 X KT66, rectifier: GZ34 or six-tube chassis (late 1966-1972) including preamp: 4 X ECC83/12AX7, power: 2 X EL34, solid-state rectifier, two channels, tremolo, top gold control panel, four inputs (two per channel), eight knobs (p, b, m, t, v1, v2, s i), black covering, white or gray Bluesbreaker/Pinstripe (1964-early 1965), Marshall Bluesbreaker/Pinstripe (mid-1965-1968), or full-face Basketweave (1968-1972) grille cloth, mfg. late 1964-1972.
The Bluesbreaker was originally equipped with Radiospares transformers, and in circa 1965 Drake transformers began being phased in and the Marshall Bluesbreaker/Pinstripe grille cloth was used exclusively. During the second half of 1966 the upgraded JTM50 chassis was offered with a full 50 watt power rating, which utilized the EL34 power tubes, Drake transformers, and solid-state rectifier. In 1967, the JTM designation was changed to JMP for Jim Marshall Products. The control panel designations remained the same as above. By 1968, the Bluesbreaker was known as the JMP50, although it kept the same cabinet dimensions and control panel layout as the circa mid 1965/1966 Series II, but included the new Basketweave full-face grille cloth, introduced in 1968 and the revised electronics stated above.
Unlock full access to Blue Book
You are currently viewing the free portion of the Blue Book of Guitar Values. To unlock full access, choose a subscription for more benefits including access to all guitar values, pricing history, create a collection and more!
BLUESBREAKER MODEL 1962
View Details
- 30-35W (1964-mid-1966) or 50W (late 1966-1972), 2-12 in. Alnico (1964-mid-1965) or Ceramic magnet (mid-1965-1972) speakers, guitar combo, seven-tube chassis (1964-mid-1966) including preamp: 4 X ECC83/12AX7, power: 2 X KT66, rectifier: GZ34 or six-tube chassis (late 1966-1972) including preamp: 4 X ECC83/12AX7, power: 2 X EL34, solid-state rectifier, two channels, tremolo, top gold control panel, four inputs (two per channel), eight knobs (p, b, m, t, v1, v2, s i), black covering, white or gray Bluesbreaker/Pinstripe (1964-early 1965), Marshall Bluesbreaker/Pinstripe (mid-1965-1968), or full-face Basketweave (1968-1972) grille cloth, mfg. late 1964-1972.
The Bluesbreaker was originally equipped with Radiospares transformers, and in circa 1965 Drake transformers began being phased in and the Marshall Bluesbreaker/Pinstripe grille cloth was used exclusively. During the second half of 1966 the upgraded JTM50 chassis was offered with a full 50 watt power rating, which utilized the EL34 power tubes, Drake transformers, and solid-state rectifier. In 1967, the JTM designation was changed to JMP for Jim Marshall Products. The control panel designations remained the same as above. By 1968, the Bluesbreaker was known as the JMP50, although it kept the same cabinet dimensions and control panel layout as the circa mid 1965/1966 Series II, but included the new Basketweave full-face grille cloth, introduced in 1968 and the revised electronics stated above.
Unlock full access to Blue Book
You are currently viewing the free portion of the Blue Book of Guitar Values. To unlock full access, choose a subscription for more benefits including access to all guitar values, pricing history, create a collection and more!
BLUESBREAKER MODEL 1962 REISSUE
View Details
- 30W, 2-12 in. Celestion Greenback speakers, guitar combo, six-tube chassis, preamp:4 X ECC83 (one dedicated for Tremolo circuit), power: 2 X 5881, GZ34 rectifier, two channels, tremolo, top gold control panel, four inputs (two per channel), eight knobs (p, b, m, t, v1, v2, s, i), power switch, standby switch, two speaker jacks with impedance selector, mains voltage selector, black covering, reissue Bluesbreaker grille cloth, 67 lbs., a reissue of the late '60s Series II Model 1962 Bluesbreaker, mfg. 1989-1999, 2002-2019.
Unlock full access to Blue Book
You are currently viewing the free portion of the Blue Book of Guitar Values. To unlock full access, choose a subscription for more benefits including access to all guitar values, pricing history, create a collection and more!