How to convert FLAC to WAV ?

I spent a month ripping to all formats, FLAC, WAV, AIFF. I found absolutely zero difference between the above. i went with FLAC since it was smaller and held tags, there was no reason to go with WAV and in fact there were reasons not to. Curious why you would do this?

Forgot to mention I am also running the clock out of the DAC into the soundcard.

This is a very long ongoing debate. There are the mathematicians out there that will insist there can be no difference, I am of the camp that I understand there can always be a difference, so I spent a long time ripping many files, all in DB Poweramp, using a very highly resolving system including an Esoteric D-70 (PCM 1704 DACs), RME 9632 Sound card, ASIO, custom made $800 digital output from RME soundcard into my DAC via XLR. All running direct into my Pass Labs amp using the DAC as a volume.

Now maybe there are differences with USB? I have found USB to be vastly inferior to SPDIF or XLR or even Toslinnk for that matter.

With that being said I found HUGE differences between playback software and settled on JRiver.

Back to WAV vs. FLAC, I would have willingly ripped all to WAV but again found zero difference, I wish I could have but couldn't.

I am intrigued by the USB topic. Steve, are you saying that USB will beat my current setup I described above? I would love to put it to the test, thoughts?