K&K Phono Preamp questions.

Polarity + mute, eh? Good one. 

Polarity I know. Mute I know. Polarity + mute, that's a new one.
Oh wait, I see. http://www.kandkaudio.com/maxxed-out-phono-stage/
Turns out all the buttons and switches are exactly what they say they are:

The top button is mute.
Middle polarity.  
Bottom stereo/mono.  
Ground is ground. Connect your turntable to it.  

The switch in between the phono input RCAs is to switch the outputs. Select the one you use. If you get nothing out, flip the switch, you selected the wrong one.

Polarity can be AC, like on my Herron, or it can be reversing the polarity of the output. Either way it really could not matter less. The whole purpose is to let you try it both ways and use the one that sounds the best.  

@wturkey,

Millercarbon is correct, it's all straightforward. Which do you own, the Maxxed-Out or the Trio? I own a Trio.

Thanks for the feedback. I'm not sure which exact unit this is. It's got the 2 cork knobs on the front. It's very similar to this unit. 

https://www.usaudiomart.com/details/649436923-kampk-se-phono-preamp/

Thanks again for the help.