Hello, I used to have a 5150 Sig series but I sold it and when I found a Block letter for 400 at a pawn shop I jumped on it. It has all the original tubes from when it was made. My issue is, it just doesn't seem to get loud enough and I can't remember what I had to turn my sig series too. I know I need to retube for sure but how "loud" should it be on 1-2 on post gain. It just doesn't have enough balls for what I remember my old amp having when it was brand new.