Tube amplifiers sound better because of the euphonic distortions they enhance the music, along with lots of other reasons. I will cover below. These are generally subtle effects most audible to musicians and very dedicated music lovers; casual listeners (those who “listen” with their eyes open while doing something else) usually won’t notice, but sometimes the difference is so obvious that people’s wives will comment that “wow, that sounds significantly better” when people use tubes at home.
Tube amplifiers measure poorly inside the lab specifically as a result of these added distortions, but these distortions are often an integral part of what make them sound better. Even today with the all-digital infrastructure from recording studio to SMSL Amplifier for years and decades and decades have used tube pre-preamplifiers in the microphones themselves. Today their outputs are fed to tube preamplifiers prior to being digitised for recording, mixing and distribution. We use tubes given that they make the music we create sound better: smoother, warmer and cleaner.
Ditto for guitar amplifiers utilized in creating music. The ways that tubes distort when pushed towards the edge tend to be more musical than the artificial sounds that come from transistor amplifiers when overdriven. Some transistor guitar amplifiers attempt to mimic tube distortion, but that’s a different article.
Needless to say these are generally all very broad generalizations, and this is simply the maximum amount of due to circuit designs used in combination with tubes or transistors because the devices themselves, but what are the distortions along with other reasons tube amplifiers sound better?
Tube amplifiers have much more distortion than solid-state amplifiers, but most of it is second-order, which is quite musical. That’s why it’s called “harmonic” distortion. Second-harmonic distortion is the same note, an octave above. Ditto for higher-order even harmonics; they are also exactly the same note more octaves above. Even-order harmonic distortion is really so pleasant that back in the 1970s the Aphex Aural Exciter was extremely popular in recording and broadcast specifically since it was designed to generate and add these harmonic distortions! You are able to still purchase it today.
Not only is tube amplifier distortion harmonious, it increases as things get louder – exactly as they actually do in a musical performance. As instruments play louder, or as you hit a percussion instrument or piano key more strongly, they generate more harmonic content. As notes decay, the percentage of harmonic content drops again.
Tube amplifiers mimic this. A great tube amplifier like the Woo Audio WA7 Fireflies increases its distortion directly with output level across three decades of voltage, or a million-to-one power range. In contrast, here’s how a typical solid-state amplifier, in cases like this a Crown D-75, lowers its distortion with level, and then suddenly clips like crazy (the nearly vertical line on the right):
Be aware that the Woo graph is when it comes to voltage output, as well as the Crown plot is with regards to power. In reality, the Woo plot covers a power range of over 6 million to one, whilst the Crown plot only covers an electrical variety of 50,000 to one. Using this progressive, “dynamic” distortion, tubes add sharp attacks while retaining long, floating sustains for each and every musical note.
The same as our ears, musical instruments and just about everything else natural, tube amplifiers hold the least distortion at the smallest levels. This is why a tube amplifier can sound great played softly, while with transistor amplifiers individuals are usually needing to transform it up to get it sound best. Honestly, I don’t bother using my dbx 3BX dynamic expander with a tube power amp, because it adds too much dynamic impact.
Mingda Tube Amplifier sound their best on the volumes in which you really wish to enjoy them. The same as digital systems, solid state amplifiers measure and sound their worst at lower levels, and have their very best knhcnt at near to their maximum output levels where no one ever actually plays them. For normal use with normal music at normal levels, the majority of us enjoy our music at about 1mW ~ 1W long term RMS, or about .01W ~ 10W peak. For many applications, a 30 WPC amplifier is about right.
What’s sad is that the few consumer magazines that try to publish lab results usually only plot performance right down to 100mW, when in fact probably the most relevant power range in which we enjoy most amplifiers originates from 1mW to 1W. What will happen below 100mW is really important; that’s right where the majority of our music lives!
Sadly even if you pay $150,000 for a set of overpriced frou-frou solid-state amplifiers, you’ll see its reviewer said many nice things about it, but he still said “the more I cranked them, the higher they sounded” on page three. So for $150,000 they don’t sound best in the levels I would like to enjoy them? Adhere to the money; I don’t take ads from manufacturers.
Don’t let me hold you back if you want Xiangsheng Pre-amplifier, however you don’t require it unless you like to crank it, possess a big room or inefficient speakers, or enjoy very wide dynamic range classical music at concert-hall volume.