Background: The Kinks were an English rock band formed in Muswell Hill, North London, in 1964 by brothers Ray and Dave Davies. They are regarded as one of the most important and influential rock bands of the 1960s. The band emerged during the height of British rhythm and blues and Merseybeat, and were briefly part of the British Invasion of the United States until their touring ban in 1965. Their third single, the Ray Davies-penned "You Really Got Me", became an international hit, topping the charts in the United Kingdom and reaching the Top 10 in the United States.
Context: The Kinks started out playing the then popular R&B and blues styles; then, under the influence of The Kingsmen's "Louie Louie" recording, developed louder rock and hard rock sounds -- due to their pioneering contribution to the field, they have often been labelled as "the original punks". Dave Davies was "really bored with this guitar sound - or lack of an interesting sound" so he purchased "a little green amplifier ... an Elpico" from a radio spares shop in Muswell Hill, and "twiddled around with it", including "taking the wires going to the speaker and putting a jack plug on there and plugging it straight into my AC30" (a larger amplifier), but didn't get the sound he wanted until he got frustrated and "got a single-sided Gillette razorblade and cut round the cone [from the centre to the edge] ... so it was all shredded but still on there, still intact. I played and I thought it was amazing." The jagged sound of the amplifier was replicated in the studio; the Elpico was plugged into the Vox AC30, and the resulting effect became a mainstay in The Kinks' early recordings--most notably on "You Really Got Me" and "All Day and All of the Night".  From 1966 onwards, The Kinks came to be known for their adherence to traditions of English music and culture, during a period when many other British bands dismissed their heritage in favour of American blues, R&B and pop styles. Ray Davies recalled that at a distinct moment in 1965 he decided to break away from the American scene, and write more introspective and intelligent songs. "I decided I was going to use words more, and say things. I wrote 'Well Respected Man'. That was the first real word-oriented song I wrote. ... [I also] abandoned any attempt to Americanise my accent." The Kinks' allegiance to English styles was strengthened by the ban placed on them by the American Federation of Musicians. The ban cut them off from the American record buying public, the world's largest musical market, forcing them to focus on Britain and mainland Europe. The Kinks expanded on their English sound throughout the remainder of the 1960s, incorporating elements of music hall, folk, and baroque music through use of harpsichord, acoustic guitar, mellotron, and horns, and creating some of the most influential and important music of the period.  Beginning with Everybody's In Show-biz (1972), Ray Davies began exploring theatrical concepts on the group's albums; these themes became manifest on the 1973 album Preservation Act 1 and continued through Schoolboys In Disgrace (1976). The Kinks found little success with these conceptual works, and reverted to a traditional rock format throughout the remainder of the 1970s. Sleepwalker (1977), which heralded their return to commercial success, featured a mainstream, relatively slick production style that would become their norm. The band returned to hard rock for Low Budget (1979), and continued to record within the genre throughout the remainder of their career.
Question: What did the green amplifier do?

Answer:
cut round the cone [from the centre to the edge] ... so it was all shredded but still on there, still intact. I played and I thought it was amazing.