CD ripping

No need to re-rip probably if the lossless variant of the format has been used and the format works for all your devices needed.

Also if you do need other formats of existing lossless files you could look at using a batch conversion program to create the files in an alternate format. that would be much faster than re-ripping

@geoffkait ...

The Lost Chord...

Thanks for the reminder.

Update.

looks like considerable number of my files, on itunes, are AAC @ 128 and AAC @ 256.

So I used dB to rip 3 versions of the same track 

flac 5
aiff
apple losless

have to say found it hard to tell the difference and I thought my "ear" was pretty good. For example, I find poor recordings hard to listen to.

i will be re ripping as many of my older files are lossy using dB.

thanks again for the advice, really helpful. 

Steve