Anyone have the 756 pro III?

I see that when I put the volume at 1 o'clock on a received signal, the audio starts distorting.
Its not really that loud, but it starts cracking up.
I use a external speaker with 2 6" and a tweeter rated 100w.

I found 1 topic about it, but I just wanted to see if anyone here expericed this.
thanks

link
http://www.eham.net/ehamforum/smf/index.php/topic,27102.0/wap2.html

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