Why is Mcintosh C2300 not balanced?

I have a Mac C2300 tubr pre + Mac MC402 power amp combo. For the same price range, Why MC402 is fully balanced designed but C2300 is not? Is it a waste to use balanced cable between them if one of them is not balanced?

Do I need to go up to Mac C500T to bring the best out of MC402 balanced design?
There's a recent thread regarding XLR adapters where the subject of feeding single ended sources into balanced amps is extensively discussed. You need to read that post.
I have noticed many tube amps don't have balanced connecters . Having balanced connecters dos not guaranty an amp is balanced , I'm sure other posters could explain better , if you like .

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