Re: Why do my amps sound better at higher volumes?
If you're talking about Solid-State amps, they have some settings where they'll sound better, but toooo loud and they just kick over (usually abruptly) at a certain point, into a disgusting distortion. Below that level, they can work the speakers and push some air and some of them can have circuitry that lets them get a reasonably pleasing fat sound at some settings. But the range of 'good' sounds seems nuch narrower than valve (tube) amps.
Tube amps are the ones where it all happens. There are a lot of inter-related things happening that cause the 'magic' we all know and love. The tube emphasises the 'even' harmonics, as opposed to the odd-order harmonics emphasised by transistors. The even-order harmonics from tubes are the ones we find more musically pleasing.
The waveform (our guitar signal) is affected differently....with transistors, the wave shape stays pretty pure, unchanged, until at a certain level, it suddenly gets too big and the wave becomes almost a square-wave (which will sound very harsh, kinda like a fuzz-box). That's why a SS amp can sound clean for a long way round the dial, unchanged, until it hits the point where it kicks over to this gritty, dirty sound.
The tube, however, behaves very differently. As more input is applied, the output signal slowly changes shape.....which is technically distortion, but it is subtle and at the early stages, we still hear it as 'clean', but there is a warmth, a fattening, the is almost universally considered pleasing to the ear. (I once saw this sound described as being 'soiled' rather than clean, which i thought was a great descrption, hehe).
As the signal passes through several stages, getting more gain and subtle changes at each stage, a 'comlexity' builds up, all adding to the tone. I am talking about the 'cleaner' end of sound here, like a vintage amp with no master volume. The principle is always the same, but some of this gets taken to extremes once master volumes and gain and overdrive stages are introduced for heavy distortion.
In something like a standard F*nder/ M*rshall/ V*x from the early days, pre-master volume, at very low volume settings, the signal moves through the amp at lower levels, and one stage tends not to overdrive the next, and the sound will get to the speakers as an almost exact reproduction of the input. There will be some added wamth to the sound due to the even-order hamonic emphasis of the tubes. Also the transformers will not be contributing any form of 'distortion' at this point. Neither will the speakers.
As the volume begins to be increased, the signal after the volume control works the inputs of the following stages harder, and the output signals change shape, as i mentioned earlier, and what we hear becomes different....better. The waveforms bocome more harmonically complex and fuller. Of course, keep going up the dial end this progresses to 'fat' then 'ballsy' then.....'dirty'....bur progressively, and usually in a pleasing way.
I've been a player for over 35 years, have always been interested in electronics, and have been building and repairing amps for over 15 years, maybe more. I see what i am trying to describe here almost daily on the oscilloscope, and i know exactly the relationship between that and what my ears here. It is at once a pleasure and a curse. To me, there is still a 'magic', but most of it IS quantifiable.
Also....an amp can sound different on different days, in different weather, many other quirky variables.
I learnt, as a teenager, that a non-master volume amp would have volume 'zones' that worked for me. So then how could i get those tones at higher or lower volumes? I came to this conclusion....own several amps, of different power ratings. The master volume control got introduced to try to deal with this issue, but they change the core sound, not neccesarlily for the better, and have gone on to become their own sound. I am a true believer that all guitar sound should be built on a good....no....great....clean sound. Get a great clean tone (i mean 'clean' as in what we hear, which may be technically somewhat distorted,......like an old Fender turned up a bit less than halfway)....with a good core tone like that, driven tones are really something else.
One good thing....knowing how tube amps (and SS amps) behave certainly makes it easier to find an amp that suits you. Searching for the sweet spots, basically. Sometimes it's frustrating that we can't have an amp that does this stuff consistently at any setting, but such is the frustration....and the magic....(in the pre-master-volume control days, the "play LOUD' mantra was uttered....shouted....for a very good reason.....).....
.........I'm sorry....did you say something....i can't hear you.........