Cheap And Discounts Polarization Symmetry OCL Circuit 3AD6 3AD50 3AD30 3AD55 Germanium Tube 20W*2 Stereo Audio Amplifier Board Wholesale. Buy Directly From Merchant J&C Audio Store. Enjoy ✓Free Shipping Worldwide! ✓90 Days Buyer Protection. ✓Easy Return. ✓Money Back Guarantee.