My amp dates from 1070, 2X35W, everything works bought used in 1981 no problem, good bass, good treble presence over the entire frequency dynamic driver it perfectly my speakers, 3A Auditor, Waferdale Glendale Cabasses cutter for you say! (I also have: Sansui AU 7900, AU 517, Cyrus 2, Philips 4224, Kenwood KA 305, Rotel RA 611), my AT 555A is wonderful, I had the opportunity to use pre-amp for amp preamp and its separable by riders on a class A high-amp range, the result is excellent.
Surprisingly this amp does not heat up even after 24 hours non-stop use, the temperature remains low apparently it was designed to last.