Are Expensive Balanced Interconnects Necessary?

Many folks have said what I've experienced:

1. It depends; the equipment must have differentially balanced circuitry to have significant benefit from balanced cable
2. There is 6 db more level
3. Experiment - we all are people with biases.  I've first started Mogami and experimented with Kimber Kables - which I decided to buy because I thought there was an improvement in the dynamics especially at high and low frequencies.

My view is cables can compliment your system - I'd be deliberate on when you decide to invest in cables especially if you are considering upgrading other components.  

I would have to say yes, but it depends upon the ability of your system to reveal details in the music. In other words, a very expensive cable may not be able to reveal its full potential in some entry level systems. So yes I would agree with some posters here that it certainly is system dependent. 

 For example, with ARC balanced preamps, you'll get 6 dB more level using it in balanced mode.

I think that's because AES48 compliant was ignored by ARC when they designed the balanced circuit in their preamps.  I'm not picking on ARC, I'm just saying. See the articles below:

Mike

http://www.atma-sphere.com/en/resource-why-balanced.html

https://www.ranecommercial.com/kb_article.php?article=2107

I run XLR between preamp and monoblocks. After using for some time only RCA between DAC and Preamp I decided to check XLRs. With equally expensive RCA and XLRs the difference was subtsantial. Initially it was hard for me to say which one I like more as they offered tottally different musicality. And on top the aforementioned gain with the XLR further blurred the picture. I do not understand a lot about harmonics, but noticed that although the treble was somehow more fluid with the RCA it was also more fatiguing at higher levels. Probably due to different harmonics. XLR delivered more focused sound and definetly was more quiet. I lived for some time with both switching back and forth, but a bit surprisingly for me I left with no regret the XLRs in my system.