At this level of high(er) end audio why not offer balanced connections?

What really matters is if the audio equipment has a “true balanced” design. Meaning that there is identical circuits for the positive and negative signals. This means twice the parts and cost pretty much. Twice as many tubes or transistors and a higher current power supply to power it all.

Many companies just add XLR jacks to their single-ended equipment and add an extra IC or transistors (if solid state) or extra tube/s (if tube) to take the signal from balanced to single-ended. All this does is add extra circuitry and actually (typically) degrade the sound. All your doing is adding extra parts in the signal path.
If the source component (CD player, DAC, etc), preamp, amplifier are truly balanced then I’ve always noticed an improvement in sound quality going with balanced cabling (XLR or whatever). No matter the length. Blacker background (because the +/- phases are canceling out noise and artifacts), improved imaging, fuller sound, improved dynamics and low level detail, bass, etc.

I know many will say if it’s a short length it doesn’t matter. It will make a difference in sound quality if the entire system is fully balanced. When I discovered how big an improvement true balanced made I custom built my entire system up with true balanced components. My DAC has dual D to A chips outputting R/L +/- (which is common now days) to the fully balanced tube preamp (twice as many tubes), to a full true balanced amplifier. The amp actually doesn’t even have RCA inputs because that would take and extra tube. One side of the amplification stage (a 6SN7 into two KT150’s) is fed by the positive signal and the other half of the amp (the other 6SN7 and two KT150’s) is fed by the negative signal. After the amplification by the tubes the signal is combined at the output transformer. This is “true balanced “ circuitry.

Equipment that uses single-ended circuitry and a chip/extra tube to balance the signal typically adds no improvement to the sound.
Even in the digital domain true balancing of the DAC’s makes a quieter, improved sound quality. I remember when Mike Moffat first designed his Theta Digital DAC processor and found that creating a +/- signal in the digital domain and feeding two DAC chips per channel produced a better sounding unit. Quieter, cleaner, less digital artifacts, more dynamic, etc. Four DAC chips and quad parts all the way out produced amazing sound quality. That was when people were still saying “If it’s digital it doesn’t matter, it’s just 1’s and 0’s”. The next step he added four fiber optic isolation IC’s between the digital processing board and the DAC board (decoupling grounds, etc) which further reduced noise and digital artifacts.

Most people in audio now know, Everything Matters!
Anyway that’s my two cents.

This is a good thread on the subject. 

I have an all McIntosh system and I was using RCA interconnect all along but I was always getting a Hum from my system. I tried everything but couldn't get rid of the Hum completely. Seeing that the McIntosh has XLR ins and outs I bought Mugami audio cables and Neutrik XLR connectors and made up some XLR interconnects. The Hum disappeared. The sound quality remains the same, I could hear no difference compared to when the RCA was in use except the Hum. Now I no more Hum issue.

That's my experience with both type of interconnects.

Mando. 

@almandog,

Unless you are using the top tier McIntosh like the 2 boxes preamp, there is no benefit to balanced.  Even though almost all Mac equipment has both balanced and unbalanced connectors, they are not truly balanced.  If you look inside the unit, the balanced connectors are connected to the RCA connections as well.  Like I said, only their very best amps and preamps are truly balanced.  

I am willing to bet you had a problem with that particular RCA cable and if you replaced it with another RCA, the hum would have been gone as well.  I got this information when I toured the McIntosh factory in 2019, right from the engineers mouth.  They are there for convenience only. 
 

Typically if the circuit is not balanced the XLR input comes in and the positive phase runs through the normal circuit and the negative phase is just run to ground through a resistor like 100K or whatever they’re input load is. Or as I mentioned above through a summing circuit like an IC or tube or even a transformer.
I heard him issues both ways from people. One has hum on RCA no matter what interconnect they try. Or even the opposite. I remember a couple guys had hum with balanced cables and tried different ones to no avail. Never could figure that one out.

P.S.  It is not uncommon for the positive phase to be jumpered over from the input XLR jack to the RCA jack.  No big deal as you only use one or the other and it’s just feeding the amplifier circuit. 

harpo75

What really matters is if the audio equipment has a “true balanced” design. Meaning that there is identical circuits for the positive and negative signals. This means twice the parts and cost pretty much. Twice as many tubes or transistors ...

That’s not really true. A truly balanced amplifier commonly uses discrete op-amps in a differential configuration, so it doesn’t have twice the circuitry and parts count. Still, it will be more complex than a simple single-ended circuit.