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

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.

+1 for carlsbad

My single-ended preamp easily drives my 25' RCA interconnects to my mono blocks.  Of course, they are quality cables & connectors.

From what I can gather, if the preamp (single ended) has a low output impedance it would/should be able to drive long runs of interconnecting cable.  This simple fact will explain why some preamps are unable to do long IC runs.  This does little to excite me to look for a balanced topology preamp to replace my current gem.  

Sounds like bias harping to me.  Good circuit execution etc. is not limited to balanced component design.