the closest music store in germany is Music
Ebert in Konstanz. IMHO, it's very good for acoustic guitars, but the choice of bass - electric guitars - amps is poor compared to the main Zurich stores (MusikHug, Promusig, MusikKuhn, Bass Center). Nevertheless, they're friendly and helpful, you can order whatever you want and of course you get the tax refound. As an alternative, best prices and best choice in switzerland is found at
Musik-Produktiv.