audio research LS15 preamplifier

The direct by passes every thing except the gain. I would just use the RCA CD input if I were you. Any advantage you might get with the direct will probably be lost with the adapter. I have an ARC preamp and I have compared the direct to the CD RCA, my direct is also RCA. I didn't hear a difference. If you had a balanced out on your CD player then I would say use the direct. I use the direct just because I like the idea of less in the signal path. Tom

duckkiller, thanks for the information you've given.
I am using the naim cd5x cd player. any idea on how to covert from RCA to balanced input?

You can use an adapter but I would not. I would just use the regular RCA CD input of the preamp. If one day you get a different CD player that has ballanced outputs then I would try the direct. My DAC does not have ballanced outputs either. My whole system is ballanced except for my front end. Really I did not hear any difference between the direct and the regular CD input on my ARC preamp. You have a different model preamp but I doubt there is very much of a difference. I think you would do more harm to the signal by using an adapter then you would gain with the direct input.