Tube amps have a signature sound

Mrtennis, it is possible to get more detail without an excess of treble energy. This is where understanding the rules of human hearing comes in.

The traditional way to get more detail is by reducing distortion. Distortion 'masks' detail ('masking' is a quality of the human ear; one of those rules...). Usually this is done by adding negative loop feedback. While this reduces distortion overall (and thus increases detail), negative feedback will also augment certain odd-ordered harmonics slightly, but enough that our ears detect the augmentation has hardness or brightness (another rule of human hearing: we use odd-ordered harmonics to detect loudness and we are **very** sensitive to them, even in amounts of only hundredths of a percent).

Negative feedback frequently tends to compress dynamic contrasts also. Incidentally an amplifier that employs lots of feedback might measure very flat, but is very likely to sound bright.

So the way to get more detail (and impact) without brightness is to reduce distortion without using negative feedback as a crutch. This results in a detailed amplifier that is also at the same time very relaxed and lacking artificial loudness cues of the type you mention.

IOW: you can have your cake and eat it too.

hi ralph:

i think you have misinterpreted my statements. detail and frequency response are two different variables.

i said that i perceive many solid state and tube amps and preamps which are in current production to be overly resolving in their presentation as well as having an unbalanced frequency response.

at some point resolution passes a threshold which leads to unpleasant listening.

an unbalanced frequency response is also unfriendly to the ear.

most tube and solid state amps and preamps are unpleasant sounding, subjectively speaking, of course.

MrT, I interpreted your comments correctly. I want you to understand that I was not contradicting you either. What I was pointing out is that what you were reporting in your post has an underlying design issue, and what can be done about it.

IOW your perception of a frequency response issue is in fact also related to detail in many amplifiers. Here is your comment:

i find many in-production tube amps unbalanced in frequency response and overly detailed. there is often too much treble energy. i find this is the case with solid state amps as well.

I was commenting to the design issues that cause 'brightness' and 'overly detailed' to be related. It is negative feedback.

Ralph, I have read somewhere that in fact negative feedback could improve an amplifier's behaviour. Is it true that there are two sorts of negative feedback: global feedback and local feedback and that global feedback is the bad one? I know this issue is a bit off topic but could you elaborate a bit? Thank you in advance.

Chris