Das ist ein simpler Piezo…
„SWR Workingman 10 Combo. SWR Workingman 12 Combo. SWR Workingman 15 Combo. SWR Strawberry Blonde Amp. Super Piezo Tweeter. Add this super tweeter with a 4.7uF x 250V Mylar Capacitor to your average bass or guitar amplifier to achieve that expensive amp sound!“