Add to Cart Quick view Amperex 3-400Z / 8163 Power Amplifier Tube Tested Full Output S/N 434587 date code 6740 Amperex MSRP: Now: $174.99 Was: Amperex 3-400Z / 8163 Power Amplifier Tube Tested Full Output S/N 434587 date code 6740 I tested this 3-400Z, in an Ameritron AL-80 Amplifier and it is performing at full output. date... MSRP: Now: $174.99 Was: Add to Cart Quick view Qty in Cart: 0 Quantity: Decrease Quantity: Increase Quantity: Price: MSRP: Now: $174.99 Was: Subtotal: Add to Cart