RCA versus XLR interconnects

Got a amazingly fast reply from MacIntosh:

"The 2300 preamplifier circuitry, XLR’s are converted from bal-unbal on the way in and unbal-bal on the way out.

Converting involves a single op-Amp of added circuitry. While added circuitry does add noise to a signal,

XLR connections cancel any noise induced along the cable, which will be infinitely more than the noise created by the single op amp.

The MC302 Amp is differential."

IMO, purists would probably only accept full differential with identical circuits. Op-Amp converts to a balance signal on the way out but does not preserve balance circuitry in the component. In any case, except for the uber high-end (which is not my system), it probably doesn't make much of a difference except of some DB gain for XLR's. @ghdprentice advice that the quality of the interconnect matters more than whether it's XLR versus RCA makes sense, at least at my level. 

all my electronics are Ayre....differentially balanced...hace all xlr cables including phono input....dead quiet even at full volume.

1. Balanced vs. Unbalanced: XLR cables are balanced, while RCA cables are unbalanced. Balanced cables have an advantage in rejecting interference and noise over longer distances, but for short runs (less than 3 feet), the difference in noise rejection may not be very noticeable.

2. Equipment Compatibility: Consider the compatibility of your audio equipment. Some devices only have RCA connections, while others have both RCA and XLR inputs/outputs. Ensure your equipment can support the type of cables you plan to use.

3. Sound Quality: While XLR cables are generally considered to be of higher quality, the difference in sound quality for short cable runs may not be very significant. The audible difference between RCA and XLR cables is often subjective and may vary depending on the specific components and the overall quality of your audio system.

4. Cost: XLR cables, especially those of high quality, tend to be more expensive than RCA cables. If you're on a budget and don't require the added benefits of XLR for short distances, RCA cables may be a more cost-effective choice.

5. Future Expansion: Consider your future plans for your audio system. If you anticipate expanding your setup or adding longer cable runs in the future, investing in XLR cables now may provide more flexibility.

In summary, for short cable runs (less than 3 feet), the choice between RCA and XLR interconnects may not make a significant difference in sound quality, especially if your audio equipment is not very susceptible to interference. Both RCA and XLR cables can work well for these short distances. If your equipment supports both types of connections and you want to future-proof your setup or prioritize the highest possible quality, you may opt for XLR. Otherwise, RCA cables can be a practical and cost-effective choice.

I spoke to more than one designer in the audio industry and believe me very well respected in both cable manufacturing and equipment design and ALL SAID THE SAME THING XLR DOES NOT MAKE A DIFFERENCE NOT ONE LITTLE BIT in the sound

tokushi

XLR cables are balanced, while RCA cables are unbalanced. Balanced cables have an advantage ...

It is the circuit, not the cable, that determines whether a component is balanced. Some differentially balanced components use RCAs on the inputs, such as the ARC Reference Phono preamps. Some components use only XLRs on the inputs and outputs but in fact are single-ended components, and use only two pins of the XLR connector.

Depending on the component design, balanced circuitry can yield 6dB greater output when using the balanced input rather than a single-ended input.