Hot on the heels of my little article yesterday about the re-emergence of vinyl record sales and the benefits of valve amps over transistor/IC powered ones, emails have been pouring in from readers all over the place, some supporting my thinking, others deriding it!
That’s all very healthy, I think. At least it creates a kind of forum where these things can be intellectually discussed.
Lots of people are asking why I think valve amps give better sound. Well, questions like these are like lighting the touch-paper to a stick of dynamite with me…..electronics has been my career in the past….I spent around 20 years in the field, dealing with valve (tube) circuits and then working with transistors and IC’s too. So you see, once the subject is open, there’s no stopping me and I tend to kind of get carried away with things!
To address the question then….why are valve amps better sounding? Firstly, it’s a purely subjective thing. Something that sounds really cool to me, may sound like absolute trash to you….it all depends on the faculties Nature has given us, namely our ears and how our brains process what we hear.
However, in a nutshell, and without getting too technical, the main reason why people like me keep pushing valve amps is because they produce “harmonic distortion”. Now distortion is generally a no-no in ant piece of electronic equipment…in general, the lower the percentage, the better the equipment. That is one reason why circuitry that is extremely linear is needed to cater for the performance of semiconductor digital devices these days. Things have gotten so advanced, that increasingly better and better supporting devices are necessary to cope with such a high level of quality.
But valves are inherently not very linear devices….they are prone to producing harmonics and semi-tones, and it is these harmonics and semi-tones, especially even harmonics, which give valves that extra something that semiconductor devices lack…..this pleasing effect is sometimes called “analog warmth” by hi-fi nerds, or “BD”, meaning before digital…see how fanatical some hi-fi enthusiasts can be!
As they say, a picture paints a 1000 words, so take a peek at the graph (promise it’s not too technical!) below, which shows the difference in outputs between valve and solid state devices:
Here you can clearly see that the valve amp output is not linear at all, whereas the solid state device is almost perfectly linear…..it is this linearity that gives digital audio it’s “clean” sound, but in doing so, we lose the benefits of non-linearity given by the valve device. (the numbers 10, 100, 1k, 10k refer to the audio frequency spectrum that we humans can hear; in general, human hearing ranges between 20Hz to around 20kHz). Still with me? Good!
It’s not only valves that provide harmonic distortion, but also another component in a valve amp, which is the transformer. This also adds harmonics (caused by a wonderful thing called hysteresis and saturation…but we won’t go into that here…too techie!) to the overall out put sound of a valve amp, so at the end of the day, we get a conglomeration of pleasing sound coming out of the speakers.
Such is the general acceptance of this warmth from valve amps, that even engineers nowadays are trying to add that feeling somehow to their solid state (semiconductor) devices.
It’s the same with our digital cameras…..enjoyment of the end result is not always about precision or accuracy…..many times, it’s about the mood, the subtle enhancements and character that will make the end result more vivid and interesting.
So there we have it, folks….these are the main reasons why some people keep pushing valve amps for their hi-fi uses rather than present technologies. If there are any readers here who have a slightly technical bent like myself, here’s a typical valve amp circuit for you…and please do let me know what your views are on this whole subject…..
all photos flickr.com