Lots of the trappings of high-end audio tools are extra than scientific actuality. For years, fans have insisted that valve amps sound higher than strong state ones – however on this subject, there’s actual science to again that declare up.
“Though strong state diodes and transistors are cheaper, extra sensible, and technologically extra superior than glass valves,” David Keeports, a physics professor from Mills School in California, “valves survive as a result of so many guitarists are exacting about their tone, and like the sound a valve amp offers them.”
Keeports used a Bugera hybrid amplifier in his experiments, which incorporates each a valve preamp and a strong state energy amp, to check the totally different applied sciences. He ran a 200Hz sine wave by way of the amp, first turning up the achieve with the grasp quantity set low, after which vice versa.
After analysing the ends in Logic Professional X, he discovered that the ensuing sound weaves delivered dramatically totally different harmonic outcomes. “A reasonably overdriven valve amp produces robust even harmonics, which add a sweetening complexity to a sound,” he mentioned. “An overdriven transistor amp, then again creates robust odd harmonics, which may trigger dissonance.”
As well as, valve amps give musicians extra choices – due to the physics of how valves work. For those who overdrive push a little bit, solely the highest of the sound wave is flattened. For those who push it tougher, nevertheless, it additionally flattens the underside of the wave. “The shift towards odd harmonics at growing achieve is a attribute of valve amplifiers that additional explains their attraction,” mentioned Keeports.
“The even harmonics offers the advanced, heat, wealthy sound that so many guitarists want. Add to valve amp’s capacity to supply considerably dissonant but driving sounds when a guitarist assaults strings tougher and turns rhythm taking part in into lead taking part in, and valve perform creates simply the harmonics a rock guitarist wants.”
“Skilled guitarists do not simply play their guitar – additionally they play the amplifier.”
The complete particulars of Keeports’ testing have been within the journal Physics Training.