Alright so I'll try and keep this short. I've been using an Ashdown MAG 300 watt amp for about 6 years now, and while it has sounded nice and served me well I do need more head room. It is a LOUD amp but since it is only running 180 watts at 8 ohms the amount of clean head room is disappointing. I have 2 yorkville blue fur cabs that are good for 300 watts each and I would love to have an amp that can push one cab at its potential. So I'm looking for a versatile amp from 500-1000 watts rms. Versatility is a must. Reason being: I just got into an up and coming metal band and I need something with balls and a good mid range to cut through the distorted guitars. As well as a good amount of clean headroom so if I choose to distort I can do it nicely. I play jazz and funk as well so I want this amp to be able to produce a nice thick tone with that. A tight bass response would be cool. & I play upright bass so I need something to be able to support that half decent as well. I like my cabs..a lot, they sound nice and are very, very reliable. I am not willing by any means to get rid of them at all, so please no recommendations on buying a totally new rig. I am simply looking for a head that sounds good, versatile and can do at least 500 watts at 4 ohms. Money is not much of an issue for your recommendations but lets keep it at amps less than 1800$ new. I know the best thing to do is actually go out and try these amps out, but there are a lot out there so I'm looking for recommendations on what to try. Thanks a lot!