Marshall Amplification plc - Developing the Marshall Sound

Developing the Marshall Sound

Players like Townsend and Deep Purple guitarist Ritchie Blackmore wanted more than mere amplifiers—they wanted a new sound. They were looking for amplifiers that were louder than others on the market, and they wanted a dirtier, more aggressive sound from these amps. For this, they turned to Jim Marshall. For one thing, Marshall had experience with amplification. He had built his own PA system while he was still singing, and during the war he had worked as an engineer. "These players got onto me about building them an amplifier," Marshall told Rick Maloof, "so I went to [service manager] Ken Bran, and said, 'Let's have a go at it.'" Bran was willing but felt he did not have the specialized know-how that amplifier design required. However, he had heard of a young man working at the record label EMI, Dudley Craven, who had a reputation as an electronic whiz kid. Jim hired Craven immediately and the three men set to work creating a new guitar amp.

The bulk of the design of the amp was not original with Marshall's crew. Its starting point was the Fender Bassman amp, a popular model at the time. Craven and Bran tinkered with the Bassman's electronics. They experimented with various components purchased from cut-rate electronics surplus stores. Marshall's ears determined the course of what his team produced. "The players had told me what they wanted quite specifically, such that I could hear it in my mind what it should sound like," he told Guitar Player. Between July and September 1960, Marshall's team produced a series of prototypes. After each prototype was created, Marshall had rock guitarists—the musicians for whom he was designing the amp—put it through its paces. The first five models failed to reproduce the sound Marshall heard in his head. The sixth, however, was exactly what he had been hoping for and was christened the JTM45. It had a modest 45-watts of peak power, but after the first day in the window of Marshall's store he had 23 orders. This occurred at a time when it took nearly a week to build a single amplifier.

Business boomed. Six months after the first amp hit the market, Marshall's store moved to a larger space. For almost two years, Marshall amps were manufactured in a large empty room separate from the store. It was only in June 1964 that the firm moved its 15-man production staff into a Marshall-owned factory, a 30,00-square-foot facility in Hayes, Middlesex. Marshall's amps evolved rapidly. The original JTM45 consisted of two parts: the head, or electronic amplifier component, included an instrument input, tone and volume controls, and a power switch; the speaker cabinet housed two 12-inch speakers. Those two speakers were blown out repeatedly by the powerful 45-watt head. Worse still, they did not consistently produce the sound Marshall wanted. He modified the cabinet, stocking it with four 12-inch speakers that more efficiently used the amp's wattage and at the same time better projected the sound.

The next innovation came in 1964 when Eric Clapton, another guitarist on the cusp of superstardom, asked Marshall to build him a special amp. Clapton wanted the Marshall sound but in a smaller, more compact combo amp—an amp with the head and speakers in a single unit—that could be easily transported in the trunk of his car. Marshall responded with the Bluesbreaker. Its portability, its warm-yet-rough sound, and its price—the Bluesbreaker was half the price of comparable Fender amps—made the amp arguably the most important in the company's history.