Gadget stores in oxford street area?

[ShushNo]

Hi, I'll be in london in a few days, and I'd like to visit some gadget stores in oxford street area. Doesn't have to be on the street it self, I mean something in walking distance of the street. so anyone know about this kind of stores?

Already know about the ones in no. 190 and in no. 400 of oxford street.

Thanks a lot.