Why some preamps does not play music? Cold?

Why some preamps does not play music? Too Warm, Thick and Slow?

"Slow"... Hm... It is interesting... I’d say might be not exactly "slow", because it might have swing at the same time, but most likely wrong PRAT, that screws original melody, therefore depending on music played it varies from "Ok" to "bad". Hm.. Yep, thats probably it. In this case i guess there is no fix for that except for new preamp.(((

Preamps can be system dependent and personal preference do apply as well as musical tastes, what sounds mediocre in one system may actually sound very good in another. You might want to start by trying different interconnects and or tubes. If in the end all else fails you might need to try another pre. Some preamps are more accurate then musical, maybe that's the case here. Preamps are very difficult to get right for manufacturers.

dvavc, what's your tube preamp?   Do you know the tubes in the preamp?    You can tailor the sound by changing the tubes.

P.S. Guys, this is pure technical question. I'm not asking which preamp does it all, so please no preamp recommendations!!! I just want to understand what is causing said phenomena, that is it.
Thank you for understanding.

The reason a preamp may or may not be emotionally involving has usually to do with distortion. I'm not talking about a lot here either. Just a small amount of higher ordered harmonic distortion that is difficult to measure is easily heard by the human ear as brightness.

This is because the human ear/brain system converts all forms of distortion into some sort of tonality. Higher ordered harmonics are an excellent example- and have a further complication with the human ear as the ear uses those harmonics to gauge how loud a sound is. So when they get messed with, the ear hears it as louder, harsher and brighter.

Music is processed in the limbic centers of the brain. However, if the brain detects that there is something wrong somewhere, it has a tipping point wherein the music processing is transferred from the limbic centers to the cerebral cortex (where consciousness/intellect resides).

When this happens, the emotional connection is lost. No more foot tapping, none of that feeling of wanting to dance.

So what the designer of the electronics has to be aware of is what forms of distortion to which the brain is most sensitive, and avoid them through design. This is not really that hard if you understand engineering, what is hard is that you have to know the engineering and the physiology at the same time.

One example of a design technique that causes a loss of emotional impact is the use of loop feedback in the circuit. Loop feedback, while overall suppressing distortion to a great degree, actually **adds** higher ordered harmonics to the signal. You already know the effect of that. But it does more- there are usually intermodulations at the point that the feedback is applied (the feedback node). These intermodulations may not have any musical relationship to the signal at all, at being at a low level, exist more as part of the noise floor of the preamp or amp. This has been known for the better part of 60 years (see Norman Crowhurst- he was writing about this in the 1950s).

Now it happens that the ear has a masking principle- wherein the presence of a louder sound will mask the presence of a quieter sound (this is the basis of the encoding of mp3 files BTW). This is well-known. What is less well known is that there is an exception to the masking rule that has to do with hiss. This is likely evolutionary as wind and water make hissing sounds in the natural environment, and the inability to hear noises below the hiss might have profound survival aspects!

So we can hear about 10-20 db into a natural hiss noise floor (the exact amount being a matter of the individual and also debate, but the 10db figure seems to be a solid). Now if the noise floor of the circuit is composed of harmonic and inharmonic (intermodulation) noise (as opposed to the hiss that arises from noise sources in the circuit unrelated to loop feedback), the result is that even though consciously we can't hear a lot of difference between the two noise floors, the unconscious portion of our brain (which is about 95% of the brain structure) can detect that something is wrong. 

When it does so, music processing is transfered to the cerebral cortex: the emotion connection is lost.

Does that help with the understanding? Any questions?