Cheap And Discounts 6X Mini Preamp Op Amp Module Amplifier Dual Channel NE5532 Preamplifier Tone Board 5 Times Wide Voltage 12-30V Wholesale. Buy Directly From Merchant All 4 AutoMoto Store. Enjoy ✓Free Shipping Worldwide! ✓90 Days Buyer Protection. ✓Easy Return. ✓Money Back Guarantee.