Loud and Louder – The Amp Thing

Part 1: The Jim Marshall Story


 Electrified guitar was developed so that the guitar could be heard among the power of the Jazz Big Band.  As popular music developed there was a growing need for more power to be heard in large venues.  The P.A. systems were just that – for amplifying the human voice and thus for the singer.  The instruments were heard under their own power except when a horn fronted for a solo.

The Beatles became the most popular band on earth.  Even when playing She Stadium there amplification consisted of their Vox guitar amplifiers and the stadium’s distributed Public Address system.  It didn’t really matter as the Beatles couldn’t be heard over the screaming in any venue for some years.  While Vox achieved fame from the Beatles, Fender amps remained the preferred brand in the US.

Jim Marshall was a drummer in dance bands at the age of 15.  He also had a job in a factory and was an offsider for a milkman.  Jim saved his money and on 7th July, 1960 opened a music store in Hanwell (West London).  He not only gave drum lessons and sold instruments but began to customise amps and speaker cabinets.


In late 1962 he developed a design based on Fender’s Bassman.  This was in response to guitarist’s demands for a dirtier, more distorted sound and a lower cost alternative to Fender & Vox.  Jim Marshall’s JTM45 coupled to a quad box (4 x 12” speakers in a relatively small box) was the start of legend.  Typical rigs to date used  2 speakers (Fender Twin) or  many smaller ones (Vox – 8 x 8” & original Bassman 4x10”).  Eric Clapton, Pete Townshend and many others quickly adopted these rigs, and by 1964 Jim had a factory.


The rig was loud but the rest of the band could match – drummers were always loud, bass players started using the same gear (tone control treble down and bass up) and Jim Marshall started producing P.A.s, using the same technology, for the singers.  But the guitarist and bassist of one band found that it still wasn’t loud enough.  The Who were playing pop concerts where screaming by the audience was mandatory.   They also had a very loud and manic drummer so in late’ 65 John Entwhistle talked Jim into building a 100 watt amplifier and of course Pete Townshend wanted one.  The speaker cabinet comprised  8x12”