A Brief History of Guitar Amplification
The very first basic guitar amps were developed in the 1930s, and were the result of engineers utilizing the radio and hi-fi technology of the time. Electronic amplification of guitars was driven by various factors, including the popularity of Hawaiian lap steel playing. However, it wasn’t until the 50s and 60s that major advances in technology and the demands of guitarists resulted in the classic sounding amps we know today. This was a period of experimentation and progression. Guitarists attempted to push their amps into new sonic territory and sought novel and creative ways to overdrive them.
Two amp companies who were prolific in this period were Fender and Vox. Many of their models from this era are now regarded as valuable vintage items, which feature distinctive tone and quality distortion. The Fender Bassman which was introduced in the late 1950’s, is one of the most copied amps in history, and is distinctive for it’s rich distortion and compression. Other Fender amps were pioneering in the sense that they incorporated tremolo (Fender called it ‘vibrato’) and spring reverb units. The most famous Vox amp is the AC30. Used by artists such as The Beatles, the Rolling Stones and Queen, AC30s supported a wide variety of musical styles by being able to produce tones that ranged from clean and punchy, through to raunchy overdrive.
The rock scene in the late 60’s gave birth to the Marshall stack – powerful amps in double 4X12 speaker cabinets. These amps had great distortion at high volume, and were famously used by artists such as Jimi Hendrix and the Who. In the early 70’s there was a craze for ‘Hot-Rodding’ amps, where engineers would try to squeeze as much extra gain and distortion as they could from classic Fenders and Marshalls. This resulted in new amplifier producing companies including Mesa Boogie, whose amps featured high sustaining, hi-gain distortion.
Further advances in technology saw amp makers offer master volume controls, which meant that distortion could be obtained at any volume, where previously, it required the amp to be cranked very loud. Channel switching was another progression. This allowed guitarists to choose ‘clean’, ‘crunch’ or ‘lead’ guitar tones via a foot-switch.
Guitar amps have been traditionally powered by valves and despite an attempt to make solid state transistor technology widespread, valve amps today still dominate the top end of the market. Solid state amps are generally more economic, reduce the heat of the amp and are lighter, but have never been able to replicate the tone of tube amps. Despite this, solid state amps as well as amps that combine solid-state and valve technology (called ‘hybrids’ are quite common in the small to medium amp market.
Recent years have seen the introduction of modeling technology. This is where classic tube amplifiers have been scientifically analyzed, and their sonic signatures reproduced digitally. This allows a guitarist to own a single amp that produces the tones from scores of classic amps and effects units. It has allowed modern day guitarists to access a very wide sonic palette for an affordable price.
