Horse puckey! I just got up, walked over to my handmade true-balanced end-to-end differential headphone amp, disconnected my Mogami XLR interconnect from my R-2r resistor ladder DAC and measured the pins on its standard Neutrik-branded male connector. ShOcKeR! All pins are the same length.
So I thought, well there’s *no*way* anyone would mansplain so authoritatively if they weren’t actually knowledgeable. Better give them the benefit of the doubt and find another cable with a non-Neutrik XLR connector on it. It took some digging, but I eventually found another cable with Amphenol XLR connectors. Nope. All the same length.
I’m going to trust Nelson Pass, Atmo-Sphere, and the electrical engineering professors who mathematically demonstrate how differential amplification (internally balanced components) are inherently better performing but also more difficult to engineer. Not a lot more difficult, but clearly complex enough to confuse your average solder jockey or audiophile store salesman.
Now, maybe some old Korean War era PA system cables used an early version of the standard with a longer pin, but they did a lot of things differently 60-70 years ago. Today, unless you can link to a whitepaper or standards doc that specifies a longer ground pin, I say we can safely assume the pins are the same length.
PS: When people say balanced is not inherently better, they mean that having a balanced circuit in a badly designed amplifier isn’t going to make that amp sound better than a really superbly engineered unbalanced amp. It doesn’t overcome an otherwise poor design.