i think we are making this too hard
to figure out how one new piece of equipment sounds, just insert it into a ’reference’ system that the owner knows very very well and hear the SQ delta (if any), substituting for the reference unit ...
in this case, discussing a preamp, insert pre X in place of reference pre A (and reference pre A may indeed be no preamp at all)
then, to confirm, if you want to be more sure, try against a second reference pre B... if you wonder if there is pre to power amp matching issue, try a second reference power amp
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speaking in ideals or in theory is just that... in the real world everything has an impact on the sound
and we also don’t know what the signal actually sounds like, since there are various equipment and transducers capturing, processing and reproducing, none of which are ’ideal’, and most far from it
to figure out how one new piece of equipment sounds, just insert it into a ’reference’ system that the owner knows very very well and hear the SQ delta (if any), substituting for the reference unit ...
in this case, discussing a preamp, insert pre X in place of reference pre A (and reference pre A may indeed be no preamp at all)
then, to confirm, if you want to be more sure, try against a second reference pre B... if you wonder if there is pre to power amp matching issue, try a second reference power amp
****************************************************************************************************************
speaking in ideals or in theory is just that... in the real world everything has an impact on the sound
and we also don’t know what the signal actually sounds like, since there are various equipment and transducers capturing, processing and reproducing, none of which are ’ideal’, and most far from it