Can anyone help me identify this component? It seems to be a positive adjustable voltage regulator, TO-3P package, capable of at least 100v input. Output in this amp would be about 30v. There are absolutely no identifying numbers or logo's on mine, though a friend with the same amp has a small logo on his regulator that looks like it might be S something (SGS?) Input is on the centre terminal. (So it is NOT a TL783). The guy who built the amp is overseas and out of reach. Please help me ..... I am missing my music!!!!!!!!!!