amarra or pure music..?

What is it about these programs that make them sound different I wonder?

Are they doing some kind of digital signal processing to produce a certain sound?

I would expect any software programs used to play digital audio to just pass the bits by default (ie do nothing to affect the resulting sound) unless you chose to alter it in some way, similar to most audio signal processing devices?

'I have found nearly all software sounds slightly different. Don't ask me why! "

There are endless reasons why this might occur. You are pretty much at the mercy of the software.

But, if it were me designing these tools, I would envision a good design would merely stream the existing data in real time as needed by default and not do anything to the bit stream unless the user specifies. Similar to being able to bypass processing on an analog equalizer or other signal processor as desired.

Of course, bugs are always possible as well, meaning even if designed to work properly, the program still does not.

One reason I stick with Windows Media Player for example is I have found it to be very robust and reliable which is what I would expect in that it has been around through multiple revisions already, has a large user base and is designed by a major software vendor who knows as well as any company how to do these things right.

I am not very trusting off one off software vendors when it comes to this kind of thing. Doing it right is hard and takes both time and money (like most things).

I'm pretty sure Windows MEdia player just passes the bit stream and does not change it by default, at least when used just as a music server and not player.

Newer versions do have a loudness leveling option that helps keep different loudness level tracks more equal level, but that is it and you have to select to turn that on.

Maybe some players that target high end audio users go for a "house sound" to help distinguish them from the competition along with the various features? I suppose these "components" should not be much different from a marketing perspective than the more traditional ones.

Its possible I suppose that different software sources might sound different with an attached DAC again depending on how well it is able to provide the bit stream in real time. PErhaps jitter comes into play here similar to other scenarios.

I use a network music player (with outboard DAC) connected via wifi network to the laptop I use as a server. I think in this configuration in particular, the interaction between the remote (to the windows server) player and the DAC is what determines the exact nature of the sound (jitter, etc.)with any particular DAC. I suppose when the player is onboard the PC the same types of interactions would occur but the nature of the hardware and software involved is different and quite variable.

So two things I could envision accounting for sound differences from player to player are 1) the "house sound", if in fact a distinct one exists for the player, at least in some cases perhaps, and the player/DAC process and interaction in regards to jitter.