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.

Does anyone else have experience comparing the "Direct" input, using balanced outs from their CD player or DAC vs. using the "regular" CD input using RCA cables without any adapters, that is. Any significant audible gains in going balanced in "Direct"?

There's no point in using the balanced input because either way it's going to be a single ended signal. Just use the rca input jacks, that's what I did.