Only small electrolytics replaced, all small transistors with the corroded wires replaced, new LED for on/off indication placed, new speaker terminals for speakers A. However good they may be, I refuse to install gold plated terminals because I think it looks tacky on an old amp like this…
Soundwise I like the AU3900 and in general this series for its ‘sweetness’ for which Sansui is well known.
In many Sansui (and other) amplifiers of the early ’70-ies these transistors can be the cause of a lot of problems, usually noise and ‘crackling’ in the sound. The black corroded wires of these transistors are indicative of this problem. Replacing them all is the only proper solution.
Tidy and sturdy; new red and black terminals replacing the somewhat flimsy original connectors, at the same time allowing for 4 mm banana plugs to be used.
Replacing the lightbulbs in the two meters by new incandesant bulbs was the most beautiful way, if only they would have fitted… Removing no more than one mm of plastic from the holes in the back plates of the meters without damaging anything takes patience and a steady hand.