(heh, recently saw American Gangster...)
Bill and company talked me out of SACD when I started here at CNET a year ago or so. They said the format was dead. They were already told that I was a classical buff, oh well. I guess I might be thankful. If I went multi-channel.... oh boy.... Some great new classical recordings are coming out as hybrids now, and they can cost. Just got one recently, of course only using the redbook layer. (The hyrbid is the only version available).
$300 firm? Keep your Oppo. If you had double that budget, and we were only limited to upgrading your audio source, I definitely vote for the DAC over a new player. I have zero confidence in the reliability of changers/carousels anyhow.
If you had $300 burning in your pocket to spend on audio, I vote for treatments or EQ. (I know you might want a sub, ok, can I have "two votes"?). But treatments are not exactly cheap if you don't make them yourself. I know you like bass response as you've mentioned from the rock you listen to, and I can only imagine that bass traps in every single corner of your room would help tremendously. Will your guests think you are completely nuts? Yeah, probably...
I need EQ and treatments. I am in a holding pattern for several months more, to see if I will be able to split my HT into a separate 2-ch as well. If I am able to pull it off, the 2-ch will most likely get its own dedicated room, and not the HT, although that isn't the easiest decision. (Remember when you were educating me on projection screen technology? I even checked out theater seating!). I cannot wait to have wall treatments, bass traps, Audyssey, better bass mgmt, etc. I am getting some healthy peaks at numerous freq's due to reflections (remember I have dipole mains) and modes.
Digression is over. I know you've got the gist of what Im saying.
p.s. oh ya try to keep the recordings as cd-quality. Some have experimented with varying levels of minor compression and found little or no ill-effect. Im sure it depends on everything... recording itself, listener, setup, etc....
p.p.s. IIRC, there's a nice fellow ML owner who has two of those 400 disc changers, because his wife is wheelchair bound. He also has a modified Oppo player that he recommends very, very highly, but we are talking about a grand.... If you want me to ask any particular questions about the changer, I can. Or better yet, I can tell you his handle at what forum if you want to pm him questions. You've got my email.