Best audio shops in the Chicago area?

I am going to be spending some time in Chicago in the near future and would like to visit some 'user friendly' audio shops. Of interest to me are full range speakers and tube amps. Of course, I'm receptive to any audio product that might enhance my home system. A couple that I have come upon here in Audiogon are Promusica and Holm Audio. Any help fellow audiophiles in the Windy City could give me is sincerely appreciated!