I've been using my SVT4Pro/410HLF as my main rig at church for the past 2 years and the more I play thru it the more I don't like it. I thought that maybe it was the cabinet which is very loud, boomy, deep but not as modern sounding as say an Aguilar GS410 in comparison. Got the bright idea to start bringing my Carvin B1500 to drive the 410HLF and OMG what a difference, every note pronounced, defined, clean, deep, low and all that with the controls around 12 O'clock. Even the other band members noticed the difference. I know I'm comparing apples to oranges but can two heads be that different? Has anyone else fallen out of love with their 4Pro? Could it be a matter of re-tubing the preamp section?