Got a real nice tweed champ clone built that is just too bright when pushed. It has a 10" speaker in a slightly oversized cabinet. I have tried a few speakers and all sound good at lower volume clean to medium crunch. When I push the amp into overdrive (9-10 on the vol) it gets real bright and the highs are harsh and unpleasant. Can the voicing of the amp be tweaked or is this just the way the champ is supposed sound.