Jim Marshall, who made rock ’n’ roll rawer and noisier by inventing the amplifier that helped define guitarists from Jimi Hendrix to members of countless garage bands, died on Thursday at a hospice in London. He was 88.

His death was announced by the company he founded, Marshall Amplification. The Associated Press said the cause was cancer.

Mr. Marshall was part of the English music scene as a drummer, drumming teacher and owner of a store in London that sold drums as the new rock music was gathering momentum in the early 1960s. Musicians urged him to add guitars and amplifiers to his wares. One of them, Pete Townshend of the Who, said he told Mr. Marshall that he wanted something “bigger and louder.”

“I was demanding a more powerful machine gun” to “blow people away all around the world,” Mr. Townshend told NPR in 2002. “I wanted it to be as big as the atomic bomb had been.”