Need advice on HD tracks platback.

I have recently started buying some titles from HD Tracks. Some I like, Some I love, and some sound no better than the CD. I am buying them and down-loading them to an external Toshiba hard drive and playing them back through my Oppo 105. Is this the smartest way to listen to these. Also I am using the stock USB patch cable that came with the hard drive for both the down-load to the hard drive and play-back through the Oppo. Would I benefit from a higher quality cable in this location? Other gear is Rogue Audio Pharaoh, Tyler Acoustics Woodmere II, Monster power conditioner, Signal Cable Silver Resolution interconnects. Any Advice?
Never mind the typo anyone out there?
I am also using an Oppo 105 to perform D/A conversion. I use a MacBook Air to store (and download to) HD Tracks FLAC files with Aurdirvana Plus. I could not be happier with the results; see my previous post on this subject:

Admittedly my system has changed somewhat since I posted the above. But then again, what do you expect, I am after all using Audigon!
If you think that a hi-res download from HD Tracks doesn't sound any better than the CD version of the same album, don't assume that it's because of some shortcoming in your hardware (which looks pretty good to me). Keep in mind that if the sound quality in the original recording wasn't up to snuff to begin with (something that certainly is not rare), then putting out a hi-res version of it isn't going to somehow magically make it sound better no matter what hardware is being used for the digital file playback.

That's not to say that there aren't any hardware changes you could try. I suspect many would suggest upgrading the USB cable as a first measure. Something else you could look into is whether or not you like the sound any better if you play your downloaded digital audio files through software (for example, I use JRiver to play audio files stored on my Windows laptop through my Oppo 105.)
I do realize that some of the diference in sound quality is in the origanal recording. I was mostly courious about using the external hard drive in the chain(good idea or not) and if I would hear any results from a USB up-grade. Thanks for the comments.