Best DAC

I would look into DACs which are noted as being source agnostic or into splitting your budget for components such as the Regen making the rounds which filter the line between PC & DAC.

Personally haven’t tried the above however I have compared an Ultrabook as source compared to a tweaked performance tower and found the portable machine highly restrictive to the performance of my DAC. Were it more than an expirament I’d have immediately traded in my DAC!

In an attempt to level the playing field I added the same OS tweaks/playback software to the ultrabook; unlike the full sized machine the sound remained consistent through all the tweaks I made.

Your best bet is to find a used ARC Dac3.  You already have an ARC preamp and I assume you like it (as you should).  Thus, an ARC DAC makes total sense and will be an optimal match.

I've had the Benchmark DACs (still have the DAC1 as a headphone amp and previously owned two DAC2 HGC), but you can do a lot better.  For the money, they aren't bad, but a used ARC DAC3 will be far better. 

Just because Stereophile says Benchmark is "Class A" doesn't mean you're getting a DAC with anywhere near the same performance of other DACs that are truly Class A.   Trust me...I have an $11k Lampizator DAC and also had a $3k Wadia DAC and both made the Benchmark seem like Class C.

That being said...you can't overlook the source.  A standard laptop will put a ceiling on your performance that is tough to get around.  As someone mentioned, you can get things like the Regen or iFi USB 3.0 to help, but you also need something with decent processing power to avoid other pitfalls in computer audio.

Personally, if it's possible to wait, I'd save up for the $2k used budget range.  You could get a used DAC3 and/or many other previously $3k DACs that have been superseded....plus some tweaks to your server.  In the long run, you'll save money and have something closer to true class A right off the bat.

Thanks for the input everybody. I currently have the SP-6 pre-amp if that makes a difference. I saw the ARC Dac3 but I wasn’t sure how that would connect to the computer.

Would the ARC Dac7 or Dac8 be a serious upgrade from the Dac3? I know the 7 and 8 are USB capable.

1,500 for the Dac7 doesn’t seem too far off budget if it would be worth it. But are there any better options when we approach that 1.5 to 2K price range?

Also, is the Regen a piece that I would definitely want to integrate into the system? I’ll be using my laptop for a while before I invest in a dedicated music server, but it has decent power.

Thanks again

With asynchronous USB DAC computer speed should have zero effect on the sound - since computer is sending data without timing. Faster computer might even have negative effect by creating more of ambient electrical noise.