I really wish and hope I can get some help and clarity here on this issue. This has been plaguing me for years and I just dont know what to do at this point. My problem is after about 45 to 60 minutes into our rehearsals my amps begin to distort and loose head room big time. It doesnt matter what basses Im using and it doesnt matter if I have my Aguilar Tonehammer in front or not. I am going to describe the environment as best as I can but I just wonder if anyone else has this issue and what the best resolution would be. My band does have a 900 square foot studio that we permanently rent and our stuff is stationary. We do practice pretty loud all the time I would say gig volume. My guitar player is next to me running a Diesel head and a Mesa Road King together and he is loud. I am running two Mesa Titans one behind me on a 4/12 Mesa Neo cab and another to my left pointing across the room on top of a Mesa Powerhouse 1000. Matched heads and cabinets. Both of my Titans have back to mesa to have the second fan put in and limiter adjusted so they are completely moded to have all and any newer updates. I do have power conditioners on each head but they are just distributers and filters not true reserves with big toroidal supplies and caps inside. I have each amp on different circuits in the room plugged directly into the power conditioners and strait into the outlets. Extra fans behind both heads to help run cool. Basses are a Warrior JDran Signature with newer preamp, Warwick FNA 5 string, Warwick Streamer 2 5 string, Warwick Corvette 6 string and sometimes a Spector Euro 5 string. All basses get the same results. So when I first get in the studio and start to play its that magical powerful endless headroom thing where Im smiling and its like the best bass tone I ever heard. Then after pushing my equipment and everyone else in the studio doing the same its like I have a distortion box on each amp. Now I have tried no preamp, master gain mostly up and just a small amount of pre gain you name it I tried it. The building we are in is older with older power and wire. I think the voltage and amperage is fluctuating especially since we drain so much of it when we are hitting really hard. So one school of thought is the amp is starving for power and thats causing the issue. Or the Mesa stuff gets saturated when pushed hard for a period of time and I should switch to a Crest CA12 and Preamp to run both cabs with as much clean juice as I can find. I love the tone and headroom of my Titans when I first start playing and then I hate them. Any suggestions or ideas? Experience with this with other heads or power amp preamp combinations and maybe anyone with the same problem with their Mesa gear?? Before I buy all new amps or power support I just want to make sure Im throwing money in the right direction. Any amp suggestions? Aguilar? Eden? I had Ampeg and GnK and was underwhelmed. Thanks.