you have no idea whats going on,dont worry I will teach you padawan
ok,why EQ is horrible and should be avoided at all costs = pre/post ringing and phase shift,not just little but we are talking audible ringing and the amount of phase shift is just depressing.Phase shift and ringing are two worst types of distortion there is,ok except solid state/digital PCM clipping
ringing isnt harmonic distortion,whats worst with linear phase filters theres not only post ringing but pre ringing,its cancer of sound.It corrupts whole transient not only that its even before the transient hits,it destroy music rhythm and critical timing
tubes dont have ringing or phase shift,audio spectrum is coherent synchronized,solid,a natural pleasant,the original timing is left untouched.Tubes have noise whitch is audible only in super quiet parts,its rarely a problem and its just kind of soft noise not like hard clipping......... tubes cant hardclip they soft clip.Also the tube distortion is harmonic,second order especialy its very pleasant,its soft and euphonic,people love it.
currently there is no technology that can do what tube does,becose there isnt EQ with zero phase shift AND zero ringing
Actually most phase shift is inaudible all by itself because the ears are insensitive to is after 1-2 KHz. Below that there is so much phase shift in our listening rooms and recording studios that they swamp what little phase shift there is in most electronics including elextronics.
Every filter that implements a sharp cutoff rings no matter whether minimum phase, linear phase or the third alternative you didn't mention called maximum phase. The difference is where the ringing takes place whether before, after or during the impulse used for testing. Linear phase puts it first, Minimum phase puts it after, and Maximum phase puts it square on top of the impulse, which means both fore and aft. That is the kind you are obviously thinking of even though you got confused and called it the wrong thing.
Linear Phase filters for brick wall filtering of 44/16 are great, because all of the ringing is outside the audible range, at the Nyquist frequency. But they are often not the best choice for other applications in the audio band, even those they have the same phase charcgteristic as a pure delay, which are endemic in the real world.
Tubes don't have riniging but many tubed circuits do, and many of the classic tube designs were just on the edge of ringing like a bell and frying every tweeter they were hooked to. If you like tubes you must like phase shift because the transformers that are almost universally used with them add phase shift, which is why tube designs like Futterman's tried to have no transformers, which brings us around to ss desgns that generallly lack them and the phase shift that comes with them.
Tubed circuits clip as sharp as you like if they have inverse feedback. Tubes made great square wave generators back in the days when tubes were all we had. Of course tubes can hard clip and many classic designs by McIntosh and Dyna for example do exactly that. You must not have much of a test bench! I do.
Oh yes the rumor that tubes only put out second harmonics, which is exactly untrue if you actually measure them (They have an exponential transfer function based on therr principles of operation) Again you must have never ever measured a tubed amp or preamp and actually broke the distortion down by harmonic. Not only that you must have slept through second year electronics class that covered this in my day.
Well lets say that tubes only put out second harmonics. Any nonlinearity that creates second harmonics also creates IM which is aharmonic and sounds like $#!^.
Well as they say the truth can set you free, so I hope you enjoy freedom!
