Digital Neophyte - Need advice on streaming Spotify (please read!)

So I'm a hardcore vinyl guy ... built a listening room around my vinyl rig, and have enjoyed it immensely.  But, I've been expanding my jazz collection and repertoire, and I've found that a good, affordable way to find out what I like before I shell out good $$ on quality vinyl is to preview it on Spotify.  So, I'm using the USB connection on my Yamaha CD-S300 CDP to allow me to Spotify through my system.  I currently have one of my iPads connected to the CDP.  What I really like is that I can control that iPad (through Spotify) with my iPhone remotely from my listening chair.  It's awesome!  What isn't awesome, though, is the quality of the music playback.  It's not horrible, but it's certainly many steps below my analog rig.  I'm wondering what a logical, and affordable, upgrade path would be.  I would be willing to add a DAC, to replace the CDP connection I'm currently using, but I'm not sure what to get that will allow me to use my iPad/iPhone combo like I am now.  I know there's a couple iDACs out there (Wadia and Arcam come to mind) but I know precious little about them.  Or is there a better way to accomplish what I want to do?  I'm not looking to spend a fortune as this will never supplant my analog rig as my primary source.  But I would appreciate an improvement in sound quality.  

Thanks in in advance for your advice!

Tom