The Marshall Mark II - 50 Watt Models
According to Michael Doyle's "The History of Marshall", "JTM" was printed onto the left side of the control panel of Marshall amps around mid 1967. In 1968, the amps began sporting "JMP" (Jim Marshall Products) instead of JTM. JTM, by the way, stands for "Jim and Terry Marshall." (Terry is Jim's son.) The prototype amp was considered the MK I, hence the amps produced since carried a MK II designation. Some early amps did not have any MK designation at all.
The cabinets were updated in early 1976 to the larger Marshall logo (such as those featured in the above photo). New vinyl, plastic corner protectors added, and the on/off toggle switches were replaced with illuminated rocker switches. The first Master Volume model was released in 1975, and was produced through 1981. Note that this is an "overdrive the preamp" style of master volume system. To really get the most from a Marshall, most musicians agree that you'd want to get some of the power amp distortion into the picture, too. That's where a Powerbrake or SE-100 system is needed to get that "tone to the bone" signature sound.
In 1981, with the advent of the JCM800 series, which also carry the MK II designation, the "JTM/JMP" MK II era came to an end.
- 2204 head (1 channel, master volume)
- 2187 2x12 combo ("4 pronger", twin channel - combo version of 1987)
- 2144 2x12 combo (reverb, 6dB boost foot switch, master volume, circa 1978)
- 2104 2x12 combo (single channel, master volume - combo version of 2204)
- 2100 2x12 lead and bass combo ("4 pronger", twin channel: one like model 1986, other like 1987/JTM45)
- 2040 2x12 combo (as above)
- 2048 head (4 inputs, 2 channels, reverb "Artist" model)
- 1987 head ("4 pronger", twin channel, tremolo option, offshoot of the JTM45)
- 1986 head (bass version of 1987 head, high treble and normal inputs)
- 1985 head (PA version of 1987, 4 normal inputs, 2 channels)
- 1964 head (lead and bass, 4 inputs, 2 channels)
- 1963 head ("Super PA" 8 inputs, 4 channels)