The "official" word has been that none of the 10X series are recommended for use as a preamp although Oppo recognizes that many will want to do it.
FWIW, I have yet to hear any clicks or pops from any of the Oppos but I never use them without a preamp.
FWIW, I have yet to hear any clicks or pops from any of the Oppos but I never use them without a preamp.