I just picked up an AMP BH420 online sight unseen and am very happy with it. Thunderous low end! I rehearsed with it a few times and will be gigging with it this Friday night. I have owned SWR heads in the past (Bass 350 & Bass 750) but they were nowhere near as warm sounding as this amp. It does have a brittle top as some have described, but the bottom and mids all sound punchy and as low as you ever want to go. I swear it has more of a tube sound than any SS head I have heard including all the quasi-SS's that had tube preamps. I run it basically flat but it does have a wide range of settings and sound. Thanks to the TB'ers for bringing this head to my attention, your opinions were right on! This amp truley is a sleeper and I shudder to think that the Thunderfunk improves upon it. Someday I will have to check one of those into the stable too. Needless to say I am very happy with it and it cuts through great with the Berg. It is approaching perfection.