7308 is a high quality tube in the 6DJ8/ECC88 family. These Amperex have steel pins. They are designed with low microphonics and low noise. Similar to 1E88CC
New Old Stock * New In Box Limited 90 Day Warranty MFR: Amperex (Holland) SKU: 7308-AMP
The 56 is a three-electrode tube of the heater/cathode type recommended for use as a detector, amplifier, or oscillator in AC receivers designed for it.