Need advice on a new DAC <500$ new or used.

[punk_guy182]

I currently have the ZERO 24 BIT/192KHz DAC/Headphone Amp/Pre-Amp hooked to my LD MKIII hooked to to my LD T_150 power amp and I am using the the MKIII as my headphone amp and my preamp. I just need the ZERO to serve as my DAC but apparently it cannot only do that, it also serves as a preamp no matter what I do. So now I have 2 preamps and one power amp. I guess the ZERO is the bottleneck for sound quality. Anyone care to comment?

I'd like to have a DAC that does only DAC and that could have if possible two sets of RCA outputs but if it's hard to get I can stick with one set of output. Also, I am using coaxial but I can switch to optical if that's becoming the new standard.

Thanks