I’ve seen people state both that they so not influence the tuning as long as they deliver the same power and others stating that they can make headphones “sound warmer” or “brighter”. I don’t see how that would happen though and a lot of audiophiles just hear things that I feel aren’t there, like some noise difference between the Apple DAC Dongle and a 500 EUR DAC using an off the rack chip.
Take this comment from ASR:
Amps are more likely to make an audible difference than most DACs, but that certainly doesn’t mean there are audible differences between most amps
I’m talking purely about AMPs here, not a DAC combination.
This depends a lot on the headphones and the amps.
I’ve heard IEMs and headphones (HD650, HD800, ZMF, ect) that can sound VERY different out of amps depending on the headphone impedance, ect.
Other headphones (like Hifiman Ananda) barely sound different on different SS Amps. Ananda didn’t sound all that different going from a Jotunheim 2 to a BHA-1, where as something like a Focal Clear (or Arya, to a smaller extent) did sound different.
I’ve also heard amps that were touted as “neutral” sound a lot brighter/metallic than was described. Something like the Schiit Hel 2E had an amp.in it that had very obvious upper-mid glare/coloration that made hifiman headphones annoying to listen to.
At the end of the day, it was all very minor differences (with some exceptions) and there’s not a need to spend huge dollars on an amp.