UPDATE: Our friend and member Currentpeak has just found this superb interview in audio form where Powerage sound engineer Opitz describes how Angus recorded the album back then.
This is Currentpeak‘s understanding, I am posting his comment as a whole:
It is a Michael Butler’s (of Rock ‘n’ Roll Geek Show) interview with Mark Opitz. As we know, he was an audio engineer/mixer/producer for many Albert Productions’ artists including AC/DC, The Angels, Rose Tattoo = real rock royalty! (more…)