I have 5 Trace heads, an AH200-7S which I bought new in 94, an AH100, a 200watt head unit from a combo which is still waiting for me to fix it, an AH200 GP12 which I bought for £35 last year, all these are Series 6, and my most recent addition, an AH250 GP12 SMX, which is in need of a little tlc.