Sonic effects of tubes

[MrCurwen]

In my opinion, air has most to do with phase and not distortion necessarily. Although distortion is a big factor of course.

I have subjectively found that feedback (be it global or local, the latter being less significant) reduces sensations of air. I think this has to do with phase delay effects of feedback.

Also RC networks placed almost anywhere near the circuit reduce air.

I faintly recall from school biology, that the human ear figures out the location of a sound source by phase comparison (between ears). This could mean that by messing up the phase content of audio signals you would also remove any sensations of air from it.

I have absolutely no scientific proof; I would be interested in having some, so please prove or disprove my purely subjective findings. =)

 

[tomtt]

Or perhaps something else?

'better' linearity, as a function of (tube) design ?




~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


random pic zone -

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

 

[DF96]

Also RC networks placed almost anywhere near the circuit reduce air.

I assume you don't mean that literally i.e. I put an R and C soldered together on the shelf above my amp and some of the "air" disappears fom the sound?

Feedback can advance phase. A typical SS amp would have delayed phase from the open-loop dominant pole somewhere in the LF region or below. Massive amounts of global NFB move the pole up to well above the audio range, so advancing the phase.

My understanding is that we localise sounds by phase at low frequencies and transient timing at high frequencies, combined with a little frequency response variation caused by our earlobes and head getting in the way, or not.