Many current production amps ship with these as original equipment. The Shuguang 12AU7 tube type is equivalent to the European ECC82 tube and can be used in any 12AU7 or ECC82 circuit and can make for a lower gain output option for a 12AX7 should this be more suited to your plaing tastes.
Factory Tested in original box. All of our vacuum tubes are directly come from the ShuGuang Electron Group Co., Ltd. (same factory as Ruby). The matched tubes are under a precise measurement and instrumentation of original factory factory.