The Marshall JTM 45 is often written of as if it were the first high-output guitar amplifier, despite the fact that the Fender Showman was a much higher output amp and was released two years before the JTM 45. Why did the Marshall JTM 45 catch on rather than the Fender Showman? Was the Showman just widely available? Was it not available in England? Was the sound just wrong for the music of The Who? Was the breakup of the Marshall amps more desirable?