JJ Electronic ECC803 S/12AX7 A premium quality ECC803 tube that replaces any 12AX7 / ECC83 tube type. The JJ ECC803-S is a warm, full sounding tube, with high-gain. It's great sounding in hifi amps and guitar amps. The ECC803S is a long plate type ECC83 which is a prefered detail when concerning the use in hi-fi audio equipement. The long plate construction does allow a higher peak current which is especcially helpful as driver tube.