Recommend upgrade DAC

I'd go with the MHDT havana

Wavelength Proton (uses USB to power the necessities)
Benchmark DAC1 (no USB for this model but they have DAC1 w/ USB with additional cost)

I don't need, or want a USB input. Squeezebox Duet connects to DAC using coax digital cable.

You have options with Benchmark DAC1 for inputs.

Is Benchmark DAC a major step up from the Cambridge DAC Magic? If so, please discribe.

I would think you are getting close to the most recent model Bel Canto DAC on the used market. I have a Bel Canto with the SB Duet and am happy using the coax.

I also have another SB Duet on the Cambridge DAC Magic and that seems pretty close. Finally I have a Musically Fidelity V-Dac on another SB Duet. That is a lower grade system but sounds pretty good too.

I think the SB Duet does need a DAC to make the sound into music.

Tough to beat the Cambridge DAC Magic on price to performance but I like the pedigree of Benchmark DAC1. Less of the off the shelf market components and a lot of in-house development of components and software.

You want to see some type of innovation like the UltraLock™ jitter-immune clock-isolation technology versus using general parts.

The Cambridge DAC Magic with SB Duet is a good suggestion for an upgrade.

You can get this new for under $1K:

http://mytekdigital.com/products/stereo96dac.htm