dastro, I haven't actually verified each of your proposed pre choices, but it would seem that many have balanced outputs, and your Threshold S 500 II only has single ended RCA inputs. It would seem to me as though quite a bit of cost (parts, etc.) would have went into making these pres capable of true(?) balanced operation. Perhaps you might get more for your money from a pre that put more of it's money elsewhere.
Though it might stretch the budget a bit, perhaps something like a c-j PFR with it's HT pass through would fit the bill in usability, sonics, and budget. Keep in mind that in many cases you could use an unused tape output as a HT pass through.
Though it might stretch the budget a bit, perhaps something like a c-j PFR with it's HT pass through would fit the bill in usability, sonics, and budget. Keep in mind that in many cases you could use an unused tape output as a HT pass through.