XLR waste of time ?

yes, it is waste.

Yep, I agree with everyone else. Except what Ghostrider says is not totally correct. In fact the Ayre IS a fully balance piece, and in order to take advantage of that you do need to access its XLR inputs and ideally drive it with a balanced signal. If it is wired like my P5Xe phono stage, then the RCA inputs will drive the Ayre in single-ended mode; the RCAs are not wired "like the XLR" inputs. (My p5Xe has switches on the rear panel labeled "BAL" and "UNBAL". You throw the switch based on the input and use the relevant input jacks.) But read the manual on the K5Xe to be sure I am correct. I can only speak about the P5Xe. Its possible that the K5Xe will sound best driven via its XLRs, even though your source component does not output a balanced signal. Charles Hansen probably has an opinion on this.

You may also want to consider whether you can find XLR connectors that are as good as the best RCAs.

XLRs are often better than the best of RCA ICs, no worries there. Plus- all cartridges these days are balanced sources. The advantage of a balanced input on the phono preamp is that you can set up the phono system and run the signal balanced.

If you have ever wondered why the phono is the only single-ended source that needs that extra grounding wire, its because it is actually a balanced source that you are trying to run single-ended. If set up balanced, the ground wire becomes the shield of the interconnect and the plus and minus outputs of the cartridge travel inside that shield. The result is that the cable is more impervious to noise and you can run it a longer distance, especially if you have a low output moving coil (due to the low impedance of the LOMC).

The balanced cable system exists for the **sole purpose** of removing interconnect cable artifacts. You would think that audiophiles would be all over it for this reason; I suspect most people simply don't understand the benefits.

If set up balanced, the ground wire becomes the shield of the interconnect and the plus and minus outputs of the cartridge travel inside that shield. The result is that the cable is more impervious to noise and you can run it a longer distance, especially if you have a low output moving coil (due to the low impedance of the LOMC).

Well...while this may be conceptually useful, it's not strictly correct (nor how it's sometimes executed in the marketplace).

Yes, the cartridge is a balanced source. However, the tone arm cable is sometimes not geometrically and electrically "balanced" - specifically, symmetric positive and negative lead surrounded by a shield.

You'd think this would be the "default" cable geometry for tone arm cables - even with single-ended terminations. However, after ordering a "balanced" OL Silver w/ XLR terminations, I found out it is not (and I'm still irritated about this, but not enough to spend the additional money to have my tone arm cable replaced).

Oftentimes, a "singled ended" cable is terminated with an XLR adapter and called "balanced". The problem with this configuration is you do not have a symmetric positive and negative lead surrounded by a shield, but a single hot lead surrounded by a shield. The shield is responsible for carrying the negative signal.

Not only is the asymmetric geometry a problem, but the shield (that is carrying the negative signal) picks up RFI. And since the positive and negative signals are not polluted with noise equally, the balanced circuit design does not "remove" this noise.

Atmashere is succinct spot-on when he says "balanced cable system exists for the **sole purpose** of removing interconnect cable artifacts." True, 'dat!