Ampeg SVT Classic - Broken and consistent issues

Bought In 2014 loud Vietnam made era SVT head - sounds phenomenal but literally breaks down every year - constantly blows tubes and Direct Out goes out - just got repaired and retubed in April was going to play at recent big gig coming up. Anyone else have constant issues with these heads? I truly feel the amp needs boards after taking it to at least 4 different techs or just a full on replacement. Thanks