|I sometimes wonder if an expectation psychology isn't at play in the evaluation of integrated HP jacks.
I don't wonder at all. I'm certain of it.
|Someone recently posted that they thought the HP jack on their 5001 CD player was inferior
Could be. Or it could be that they were listening with phones, like Senn HD580/600/650 with high impedance and a very uneven load, which reportedly require good voltage to deliver their best bass control and transient response.
|I still cannot hear that my Cute Beyond (which I like very much) sounds better than the HP jack on my Sony MDS 940 minidisc deck, or indeed my Sony CDP 211 CD player. (It certainly sounds better than a recent Yamaha receiver, so obviously my hearing isn't completely shot).
This could be the same issue. If you are using low impedance phones, they would probably sound better out of a quality op-amp based headphone amp, in or out of a source component, because the Yamaha will have a high impedance headphone output. Something like Senn 580/600/650s might actually sound better out of the Yamaha than it would directly from the CDP or minidisc deck.
And with all of that said, I think it is probably all stuff we would have to listen for, not dramatic superiority or suckage. And while some of this is based on correspondence with the actual manufacturers, some of it is also based on what I've read here, which is, at this point, suspect. We were so wrong about receivers and integrated amps that I now wonder what else we may be wrong about. FWIW, some other seemingly informed audiophiles on other boards have said that even the high impedance output with low impedance phones issue should only be an audible problem in extreme cases...