Tubes.
Here is another thing to think about. The DACs in the DACmagic are the same as in the Cambridge Audio 640C version 2 - "dual Differential Virtual Earth balanced filter topology and twin Wolfson WM8740 high quality DACs in dual differential mode for excellent stereo imaging" - according to Cambridge. Otherwise, the DacMagic is closer to somewhere between the Cambridge 640C and 740C CD players in terms of set up and performance.
But - you can probably get a used 640C version 2 CDP for between $300 and $400. You can then sell your NAD and buy a dandy used power cord for the Cambridge - which really makes a difference with this player. My guess is that the better jitter specs of the 640C v2 combined with a good power cord would out perform the NAD plus outboard DacMagic. Either way, at the price point used, the two Cambridge products would provide a distinct step up from what you have now with the older NAD.
The new NAD C-545BEE is supposed to be pretty good too at $499, but I have not heard it yet.
Here is another thing to think about. The DACs in the DACmagic are the same as in the Cambridge Audio 640C version 2 - "dual Differential Virtual Earth balanced filter topology and twin Wolfson WM8740 high quality DACs in dual differential mode for excellent stereo imaging" - according to Cambridge. Otherwise, the DacMagic is closer to somewhere between the Cambridge 640C and 740C CD players in terms of set up and performance.
But - you can probably get a used 640C version 2 CDP for between $300 and $400. You can then sell your NAD and buy a dandy used power cord for the Cambridge - which really makes a difference with this player. My guess is that the better jitter specs of the 640C v2 combined with a good power cord would out perform the NAD plus outboard DacMagic. Either way, at the price point used, the two Cambridge products would provide a distinct step up from what you have now with the older NAD.
The new NAD C-545BEE is supposed to be pretty good too at $499, but I have not heard it yet.