I bought these for my son to play rock and not blow up my Polytone Mini Brute (20 years of gigging with it, and I didn't need to know jack about watts, ohms, or clipping). Ordered the 210 as an 8 ohm, so we could put a 115 at 8 ohms under it later. With the 210 handling 700W, I figured how could this head blow it? Duh! After learning about clipping, I called Dave at Avatar, and ordered two new 8 ohm drivers to make it a 4 ohm cab, and get the head's full 400W. He thought that would be a viable solution. For five minutes it was, but quickly turned to mush. We tried different basses, cords, speaker cords, all with the same result. The 4004 head sounds fine w/a 350 watt 4 ohm cab at the local store, or with a 260W 8 ohm stereo speaker, so I guess it isn't fried. When hooked up to the 210, and gain at 3 o'clock (just short of pre amp clip) I get distortion with the master as low as eight o'clock. The 210 in its 8 ohm version with a home built 115 underneath , (300W, 8 ohms, built to Avatar's measurements) sound great with the Ampeg SVT 4 Pro, so ultimately that's what we will get. My questions are: 1. Have any of you experienced this problem with these brands and/or models? (I'm having trouble accepting that this is happening) 2. What other powerful heads would you suggest? Carvin R1000, Carvin 1500 mono block? 3. What about using the 4004 as a preamp running from the effects send to an Ampeg SVP 1600 power amp while getting the bread together for a nice preamp? 4. What about replacing the drivers yet again to have a cab that matches the output and impedence of the head? These seem to be workable solutions in descending order of cost. Wish I had known about talkbass (and all about ohms) before starting this. Thanks for your input.