It is known that everything in audio cannot me measured. Even Pete Millet agrees and I admit he has forgotten more than I will ever know. For instance, if you use Solen Caps in a crossover of nice speakers the highs will be very tight and move towards to a sterile sound whereas Dayton Audio are more open and airy, but strings are not a clear. I am speaking of 6 to 7 dollar caps. The Jentzen caps used on the high pass on horns make an even more open airy sound and the strings all open up more and you can hear more of the wood from acoustic instruments. $10.
If course, some drivers will react differently according to ceramic or alnico magnets.
It is not subtle either.
On Marshall plexi amps the OD 225 at the first coupling cap will provide a better overall clean tone the Marshall clean which is very nice to me, whereas a Sozo has more grit. It is very obvious and can be heard in a recording.
Now I am not referring to silver or anything of that expense. Also, most use Silver Mica in tone stacks, but I prefer the old Polystryene and some ceramics. It is very easy to check. Take a 5E3 and load it with OD715 and play it and record it. Switch it to Sozo and you will have a slight amount hair on the notes even at the cleanest settings.
But I am sure I am probably just hearing things, just like some people say Output transformers are the same. Jojokeo has a recording of the same amp with swapping transformers and it is easy to hear the difference. I will admit that speakers and cabinets have the largest impact.