Did a search and found great praise and good stories on the EBS Drome 12. Got a chance buyin' one 2nd hand for 550,-. Back in the day they were 750 new... Currently playing a Rumble 75. Going to try it tuesday... Should I go for it? Any tips for me when I try it? What should I look at especially buying this combo 2nd hand to see if it's really worth it? What determines a 'good' amp 2nd hand?