I just read hyperplanar's posts and I believe it touched on the clipping issue I mentioned - I guess there are precautions taken in more modern equipment, or maybe that in real life usage it's really a "non-issue"?
I've heard some schools of thought that state that underpowered amps could actually damage drivers such as the higher impedance ones in your (I'm sure) beloved 6xx's - surprisingly, and not the other way around.
Nonsense for headphones. Only too much power destroys headphones. Power ratings for headphones are between 20mW (0.02W) and several Watts depending on make and model.
An iphone can not destroy any medium to high impedance headphones, there simply is not enough power available.
The only issue is the lack of maximum output voltage swing (1Vrms) which limits the maximum SPL.
i dont believe in this theory that too little power destroys drivers.
https://sound-au.com/tweeters.htm
@Gadget Goober That's precisely what I was concerned about. Low-power sources creating clipping in the audio that would damage the drivers. I still wonder if that might be the case. It seems to only be an issue if you're driving a low-power amp or phone to maximum levels though?
EDIT: Just saw Peanut's response, will give that a look.
From the accounts expressed here it doesn't seem like the HD600 scales in quality with better amps as many people claim....or any headphone for that matter. I am led to believe that if a driver is being pushed to a specific volume level, there's no such thing as "quality of drive" from the source. If it's playing at a certain volume level, it will always sound the same at that volume level on any equipment you play it through that isn't coloured. A high-powered amp will not sound better than a low-powered amp at the same volume level, as long as it is within a healthy operating range (so not pushing maximum volumes on either amp).
Also I've seen brought up elsewhere that neither balanced nor "higher quality" cables will benefit the sound.
I would not be inclined to believe your experiences are anything more than expectation bias from what I've learned on this topic, both here and elsewhere. It might be worth doing some objective A/B testing with your sources?
The mechanism that would damage speakers when an amplifier was badly clipping was generation of lots of powerful high-frequency harmonics. This would subject the tweeter (which normally will only handle a few watts) to an excessive amount of power. Headphones are mostly wideband affairs with basically constant power handling across the entire frequency range, and as such are essentially immune to this particular threat.