If I were you I would contact any stores that you are interested in visiting in advance as they may not be able to accommodate in person visits. That being said Tone of Music in Castro Valley is my favorite place to visit.
Audio stores in or South of San Francisco?
I'm driving up the coast this week from LA to San Francisco, and am looking for audio stores where I could get good advice on and listen to different DACs. Also, if they have a good selection of used gear, that would be a bonus. Any suggestions?