vintage marshall
A look at a seminal British rock amp – the JTM45 MKII Model 1986
how many drummers does it take to create hard-rock’s most iconic brand of guitar amplifiers? One, apparently: Jim Marshall. Having managed to save up enough hard-earned cash as a drum tutor and working musician in the 50s, Jim set up shop in his garage assembling speaker cabinets and made the move into musical instrument retail as Jim Marshall & Son in 1960. Stocking his own line of cabinets, along with Fender, Vox and Selmer amps, Jim’s store in Hanwell, Greater London, became a destination for cutting-edge guitar players, including a young Pete Townshend. By 1962, having taken heed of their suggestions, the firm had prototyped their own take on a powerful, high-wattage amplifier.
These seminal Marshalls – later known as JTM45s – were conceived and built as a team-effort by the shop’s amp tech Ken Bran, along with electronics engineers Dudley Craven and, later, Ken Underwood. They were initially constructed at the rate of about one per
week and became an immediate success with customers. With demand increasing exponentially over the next couple of years, Marshall opened its first factory operation in 1964 in Hayes, Middlesex, enabling them to increase production to around 20 units per week.
The earliest JTM45s are distinguished by their light-coloured fabric front and red-on-silver capitalised Marshall logos. In 1965, the lettering was altered to a large black-on-gold capitalised font (often referred to as the ‘block’ logo), as seen on the JTM45 MKII featured. Later that same year, the style changed again to the more widely recognised classic Marshall script logo and has remained in more or less the same basic form ever since.
In 1965, there were several different models available within the JTM45 range, including the 1985 ‘Standard PA Amplifier’; the 1986 ‘Bass and Lead Amplifier’ (featured); the 1987 ‘Lead Amplifier’; and the 1989 ‘Organ Amplifier’ MKII amp heads. Although MKIIs were marketed with certain applications in mind, there was relatively little difference to be found in their circuitry, aside from one or two very simple voicing components.
JTM45 MKII amplifiers are quoted in Marshall’s 1965 catalogue as having a “peak power output” of 50 watts, with other sources quoting an RMS power rating of 45 watts (interestingly, the JTM45 range derives its name from this presumption, along with Jim and his son, Terry Marshall’s initials).
Between 1964 and 1965, British-made GEC-branded KT66 power valves had largely replaced the earlier 5881 and 6L6GT type, lending a bit more crunch and distinctive Marshall character to the sound. A trio of high-gain ECC83 valves handled the preamp section, while a GZ34 valve was employed for rectification.
Currently on sale at Vintage ’n’ Rare Guitars in Bath for £7,995, it’s hard to imagine there was a time when early Marshalls such as this could be difficult to give away, let alone sell for such an impressive sum. These days, however, JTM45s in this condition are more popular (and rarer) than ever, with a cult following of players and collectors willing to pay the going price, having discovered their unique charms as classic blues rock amps. Consequently, many a hidden gem has been plucked from a loft over the years to be given a new lease of life. The JTM45 MKII featured was recently serviced by amp guru Neil Perry of Raw State, who not only made it sound like new, but, most importantly, made it safe to use!
“Currently on sale for £7,995, it’s hard to imagine there was a time when it was difficult to give away”