Should I upgrade DAC, speaker cables, ICs, or PCs?

I'm asking for your help in making up my mind of where to go next. I've asked this in the past and upgraded speakers first, later the amp, and lately preamp, and while the suggestions are never unanimous (nor should they be expected to be) they have been VERY helpful and I've been very happy with my upgrades.

Here's my current system:
- Rotel RCD1072 preamp
- Lamm LL2 pre
- McIntosh MC275 IV amp
- B&W 804S speakers
- dedicated power lines, and hospital grade outlets
- stock power cords throughout
- Nordost IC, the cheapest flatline ones (maybe Black Nights? not sold anymore)
- heavy gauge magnet wire for bi-wired speaker cables, an attemp to replicate Anti Cables
- room treatments: 2 16" dia DIY tube traps plus some panels.

Room treatment has brought great improvements and I'm still working on it with significant time spent there.

The weak ares to me are PCs, ICs, speaker cables and CD player, yet I don't have a budget to upgrade all of them in the near future. Maybe I can spend $1500, and used stuff is fine.

I know I'll be keeping the speakers and amp and pre for a good while, so upgrading speaker cables and pre to amp IC would be safe moves. On the other hand, if something is lost from the signal upstream, then it cannot be recovered, making the case for starting upstream...

I'm looking for opinions from more experienced "upgraders" who have gone through more iterations and have a better handle on how big an impact one or another upgrade MIGHT have. What would be the best next move, in your opinion?

Thank you!!

I would go for the CDP. The sound never comes out better than it goes in. I have a Shanling CD T-100 - around $750 used. The analog output has a nice mellow sound, unlike many CD players that tend to be somewhat on the bright side.

If you purhcase used and whatever brand, watch out for a player with an out of production drive.
I second the nomination of source. I gather your CDP is a Rotel? (You list it as a pre.) I've not listened to the Rotel seriously, but I'm betting it could be bested by 1500, especially with a used unit. A lot of well-regarded DACs could be had for that money (or considerably less) new or used; thinking strategically, that's the way I would go, since having the option to move to computer audio is a good idea. Thinking a bit further strategically, if you spend the 1500 on a source, you may very well come across used (or even new) wires down the road that would represent an upgrade for a few hundred bucks (esp. if the runs are short); and it might be easier to justify dumping that kind of money into the hobby here and there than another 1500. Good luck, John
for $1500 you could get a great DAC. You can take your time and go through several until you find the one that matches your gear the best.

With your pre/amp/speaker combo (should have an awesome warm,powerful sound) I would suggest either the Bel Canto DAC3 or the Benchmark. Although, there are a bunch of guys on here that have the Wyred4Sound that came out recently, and they love it, you may want to try that, I believe w4s has a 30 trial period.

Good luck.