Hey guys. I have been having problems with my Mesa Boogie Rectoverb. When I am playing guitar alone, and the amp volume is low, the amp works great, but the problem occurs when I am at practice. As I turn my volume up, the amp sound gets real muddy. It sounds as if I have my low end cranked, which I don't. It only happens when I start turning the volume up, usually past 9:00. I thought it may have been tubes, and I re-tubed it, and it did not help. Could it be my speaker or possibly something else? What should I do?

You replaced both preamp and power amp tubes?
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See, it's important that people clarify when they say "metal", because I pretty much always assume they are a Cannibal Corpse fanboi.
It does sound tube related
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I'm using no FX, and yes, I replaced all 5 12AX7s and both 6L6s. After looking around on the forums, some people have said it could be that I have been playing in a small room that could have caused it. I will try playing it in a more open space, and also tweaking the EQ while cranking it and see if that helps anything.
On most amps you have to change the EQ going between speaking volumes and gigging volumes. Lots of things change when you turn up the volume and you have to compensate for it. And it's not just the way the tubes work, the speaker is a factor too. You can't expect either to sound the same working at radically different volumes. You will eventually discover two EQ settings that you will use predominantly; one for low volume and one for high volume.
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