Converting Flac to Wav & Upconversion

FWIW, I think it's odd that different software players (that can be tested to show bitperfect output) can sound different playing back the same WAV or FLAC file. Heck, even different versions of the software can sound different playing back the same file.

It is thus not inconceivable that WAV and FLAC despite having bitperfect data can sound different. I remember that the Pure Music designer mentioned the need to minimize sudden/minute spikes in CPU load to improve performance and that was one of the goals of their software update. So it is not just a % of the CPU load that is averaged over time that we need to see but those sudden spikes. There was a talk at RMAF about 1-2 years back by an ESS engineer which talked about the need to look beyond steady states but also how the system reaches steady states (ie does it oscillate through large swings in values before reaching steady states). He found that large swings seemed to have a negative impact on the sound quality. I think there's a lot to the computer playback chain that we are only just beginning to understand.

The first system I noticed the difference between AIFF and ALAC (compressed lossless) was with an iPhone 3GS docked to my car's Alpine Head Unit. Not even a very expensive set up. I used the Alpine's integrated amps and a set of Rainbow component speakers.

I had done that experiment after how I noticed a CD played on an Ayon CD5S sounded a lot more dynamic and punchy vs the same CD played on my iPhone docked to a Wadia iTransport and my friend asked to change it to WAV or AIFF. I thought he was pulling my leg but did it just as a test.

After the experience with the car system, I brought the phone back to the showroom where I had tested the ALAC vs CD earlier and this time, the gap was much smaller.