Monday, August 10, 2009

Is The 21st Century Tube Amp Revival Still Sound?

By: Ja’Nelle B.

Having more or less inherited my older brother’s “almost” all-Cary system (a year 2000-era Cary CD / DVD player, Cary 2A3-based SET amp driving a pair of Thomas Transducers Brio horn loudspeakers) for almost a year now. Due to his job that requires him to be 12,000 miles away from home to be paid yet more money to buy a better stereo. Looking at this rig, I just couldn’t believe how something – except for the CD / DVD payer – that looks like could have entertained Bob Dylan when he was yet 12 could sound way better (maybe 20 years ahead?) that the surround-sound gear oft advertised on TV. Thus began my fascination with thermionic technology – a.k.a. vacuum tubes or valves as they say in “Merry Old England”.

Having then joined in our local ad hoc hi-fi club to better utilize my newly-inherited stereo, our local experts have repeated – almost ad nauseum - the virtues of tube amplification. Though I am quite knowledgeable about the basic aspects of solid-state circuit technology, the reasons behind why tube-based amplifiers sound so good – in a majority of cases – over their solid-state brethren can be so fascinating to someone like me. Somebody that’s born way after as the older hi-fi club members in our town used to say “The Golden Age of Stereo”. So what makes tube amps tick?

The main reason (that I can agree on) on what makes tube amps sound – in most cases – better than their solid-state counterparts is that with vacuum tubes, the electrons (or more properly the electron’s wave-function) – as influenced by the audio signal – flow freely from the cathode to the plate. Unlike in transistors where the wave-function has to traverse between holes and junctions and how they are biased. Electrons can be propelled as fast as 12 million meters per second in a vacuum tube, while in a solid-state device – including wire – it is as slow as 0.1 meters per second. Only the amplified signal’s wave-function gets sent at the speed of light in a typical solid state electronic system.

So this is probably why tube amps sound faster than most of their solid-state counterparts, and more musical too. I kind of make’s me detract from the joy of listening to my “inherited” Cary system if I think too much about it. Especially if I keep on dwelling why something designed during World War II still sounds better than the latest surround-sound gear being aggressively pitched at our local mall. So if you have some more recent explanations on why tube amps sound good – especially ones involving quantum physics – please feel free to drop me a line.