How to verify lossless files?

I've downloaded some flac files which I then convert to apple lossless but they are without a log to verify the files were ripped accurately. how could I check this without the log? I found audio checker but it doesn't work on mac. How do I know these files are not just converted mp3 files?

I have also downloaded lossless files ripped with itunes should i find another download or will this suffice? i understand itunes is not the best option to rip cds with?

of course I want the best quality possible, but if the difference is inaudible it does not matter so much. my setup at the moment is poor so its difficult to check by ear. I am unsure if my ears deceive me, if its just the bad speakers OR if its that lossless is awesome and mp3 is terrible which is probably why some tunes sound so different. either way i would like to verify downloaded lossless files which are without a log?

any other tips on ripping or downloading lossless would be helpful

Did you check the file extension? If it was converted to mp3 it will say audio.mp3 if you have extensions enabled. If you don't then just right click (or option click) on the converted file in finder, click on "get info" and look at what it says under "kind". I know waveform audio (.wav) is lossless and I believe audio interchange file format (.aiff) is lossless too.