Zerogravity,
The Zhaolu DAC will give you the ability to choose between 2 digital signals fed into it, a coaxial digital signal as well as a separtate toslink signal. So you could hook up your cd player (if it has a digital output) via the coaxial input and a cable box via the toslink (if your cable box has one). This does not change the ability to use any of the other inputs on your receiver.
As to whether this dac would be an improvement, that would depend on the quality of whatever digital to analog converters your presently using, like the ones internal to your cd/dvd player and/or your cable box. Given both my experience with the Zhaolu, I would say it should offer a significant improvement.
As to opinions on upgraded boutique parts offering improvements, its like bodily orifices, everyone has at least one. But that is not specifically germane to the Zhaolu. I didn't change the coupling caps to more expensive boutiqe parts, rather by the careful choice of replacement opamps, it allowed the bypass of those coupling caps. Generally, the best coupling cap, when possible, is no capacitor.
While the Zhaolu was a bargain when stock, it was obviously built to a price point. It simply doesn't make economic sense to provide $45 (retail) in opamps in a $350 dac. The replacement opamps, a pair of OPA2107 and a single LM4562 were chosen for their objectively measurable improvements, lower offsets, distortion, etc.... and the fact that subjectively they sound great together.
Randy
