There is Audio Video Today On Beach Blvd,in Westminster, Ca. If you happen to be in the area. If not like others say, go to Brooks Berdan for Wilson ( They have Alexandrias II set up) , VTL, AR, Vandersteen and other exotic stuff. (you might see La Luce TT) Brooks and Brian are sweet hearts. Really.
Or Weinhart Designs (opposite of sweet heart, but still a good guy ;-))) is a good store to go to. ( TVAD, Weinhart designs is exactly below (1st flr) where Ambrosia' used to be (2nd flr)- in same Bldg). Digital Ear used to be a great store also. The Getty and Weinhart Designs are close by.
But like TVAD says pick a place or two and plan it other wise you will burning away your valuable time shuttling around LA freeways
If you are in to Vinyl, surely visit Amoeba.