are audiophiles different than non audiophiles ?

Musicians call it "GAS" - or Gear Acquisition Syndrome (the origin is believed to be Guitar Acquisition Syndrome).

Ultimately the love of music and sound manifests itself in a large amount of gear and there is a constant desire to not merely upgrade but also accumulate.

Example of GAS

In the case of many successful male musicians this compulsive behaviour applies in other areas too...

Frogman could not have stated the case better. As a professional musician myself, I agree with 100% of his post. There are indeed more audiophiles among musicians than in any other profession, as a percentage, especially when we are talking about classical musicians in particular. It is also true, as Orpheus said, that the average professional musician hears far more than the average audiophile when listening to music - our ears are very well trained from a very young age to hear a great many different types of things, including such things as Frogman's equipment example.

I have said this many times before here, but it always bears repeating - one of the best things an audiophile could do to deepen their appreciation of whatever type of music they listen to would be to take an ear training course at a local college. Even if one is not offered, there may be a grad student in music theory who would be willing to give private instruction - this is good experience for them, too. This type of work will also help greatly in learning to hear differences between pieces of audio equipment, too.

Unfortunately, I have never even met a "classical" musician. It's possible they have different lifestyles from jazz and rock musicians. Since that was a long time ago when I hung out with jazz and rock musicians, a lot has changed, and I wrote from personal experience plus the articles in "Stereophile".

If we got really loose with the definition of "audiophile", we could probably include some of the musicians I knew.