Why do some manufacturers reverse preamp polarity in the first place?


My Rogue RP-5 reverses polarity, so I switch the pos / neg at speaker terminals. The manual does not mention this, however, I wrote the company and they the amp does reverse the polarity. 

Now my question is...why? I would say 98% of buyers of this amp do not know to reverse the cable connections. I would say most reviewers did not as well. Yes, I realize, polarity reversal is not noticable in most instances. Especially, since many recordings are all over the place when it comes to polarity (at least that is what I've read).

So the question remains...why...why not just have the amp terminals set up so the buyer can just plug in as normal?
aberyclark
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So at the end of the day, it really does not matter how the speakers are wired. Interesting. 

what type of speaker do you have as some speakers using 2nd and 3rd order cross overs have drivers of different polarity so you will never get the right polarity as each driver in the speaker could be different.

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We've had a polarity switch on our preamps since their inception. Changing speaker cables around is a real pain!