Silicon Revolution
While valves stopped developing in the mid 1950s, solid-state amps were just getting started – and their development is still going strong today
Back in the middle of the 1950s, the introduction of the world’s first transistor radio kickstarted what would become a profound shift in consumer electronics, not to mention world history. Before the arrival of the battery-powered Regency TR-1 radio, televisions, record players, jukeboxes, radiograms and anything else that needed to amplify an audio signal (including guitar amplifiers, of course) were all powered by electron valves. Sonic properties aside, valves have other characteristics that aren’t so desirable in lots of products: they’re large, fragile, they wear out and they’re not very efficient because most of the power they consume turns into heat, while the relatively high voltages and current draw make them potentially dangerous and difficult to power from batteries.
The transistor radio changed all of that virtually overnight. Within a decade, practically all consumer electronics were being manufactured with transistors. The other major landmark was Sony’s TV-8-301, the first all-transistor television, which arrived in 1960, heralding the end of the TV rental industry and, with it, the demise of the TV repair man and his leather suitcase full of replacement valves.
The music industry has always kept up with technology and guitar amp manufacturers were very quick to embrace the transistor. Most history books quote Kay’s Vanguard line from 1962 as the first ‘proper’ transistorised product. However, there were European entries from Hagstrom and Burns around the same time, closely followed by Gibson and Watkins Electronic Music. Early attempts at all-transistor, transformer-less amplifiers were not successful because the output devices were prone to overheating and failure. Still, as more robust MOSFETs (metal oxide semiconductor field effect transistors) and more reliable loudspeakers were introduced, things improved quickly.
With the arrival of Peavey Electronics in 1965, the solid-state market received its biggest future champion, followed in 1968 by HH Electronic (Harrison & Heald) in the UK, whose early IC100 amps with their green luminescent panels are now collector’s items. Despite significant improvements in reliability and more competitive pricing, solid-state amps continued to be viewed as an inferior choice to valve amps by many players – namely, you bought one if you couldn’t afford
a ‘real’ valve amp. Nevertheless, solid-state amps were very popular in the amateur and semi-pro markets, where many show bands relied on amps such as the Peavey Bandit and Carlsbro Stingray for their backlines. One notable exception to this was Roland’s pro-level Jazz Chorus range, including the mighty JC-120, whose integral stereo chorus effect defined the clean sounds used by many groups of the time. It proved to be one of the most influential amps of its era and is still in production today.
More Than A Feeling
In 1982, guitarist Tom Scholz of Boston introduced a chorus-equipped landmark product called the Rockman headphone amplifier, closely followed by Gallien-Krueger’s GK 250ML small 100-watt stereo combo, both of which became signature sounds for many rock and metal bands, most notably Def Leppard. The GK 250ML’s ‘ready to record’ tone inspired early digital modelling products, such as Line 6’s POD in the early 1990s, which prompted many guitarists to look again at solid-state options.
By this time, transistors had all their reliability issues sorted out and amp designers began to focus properly on how to replicate the deceptively simple processes that went on inside a valve amplifier. On paper, the substitution looks simple – but in practice it was anything but, with many complex interactions between components, particularly in the valve power stage’s output transformer. As manufacturers have come to realise, it’s not so much the tone they produce but the wide-ranging dynamic response and touch-sensitivity that gives valves their characteristic feel and that has kept players loyal to valve amps for all these years.
Today, with the latest components and improved analysis tools, we’re finally beginning to see solid-state come of age, with modern products from Bogner, Hughes & Kettner, Koch and Roland demonstrating the advantages of solid-state electronics with no real compromise in tone or response compared with their valve rivals. Where metal is concerned, solid-state amps are actually preferred by some players, thanks to the tighter control over EQ and dynamic response that’s just easier to accomplish in solid-state.
As we approach another decade of the 21st century, with over 100 years since the beginning of valve amplification, there are solid-state guitar amps that can easily compete with valves, although many guitarists still prefer glass, despite the shortcomings, which are no different than they were 70 years ago. Today, however, valve manufacturing is a relatively tiny industry served by half a dozen factories worldwide in China, Russia and other former Soviet Bloc countries – a far cry from giant factories, such as RCA in Harrison, New Jersey, or Mullard’s legendary Blackburn plant, churning out billions per year.
Thankfully though, there continues to be a strong demand for popular valve types including the EL34, 6L6 and 12AX7, so it’s unlikely that production will cease any time soon, and there are still respectable NOS (new old stock) numbers from many sources. Nevertheless, it’s good to see solid-state amps out there now that are practically as good as valves. Who knows, one day soon we might all be using them.