Alright, so I recently switched cabs from a hartke 410tp to an orange obc410. I am currently running an svt-3 pro from early 2000's into it. The volume seems a little low even compared to the hartke. The only change that I have made to my 3 pro is that I have swapped out the stock 12ax7's with tung sol 12ax7s (nicer tone, but definitely lowered the output at the preamp stage). My question is, am I under powering the cab or is the ampeg just doing its' usual not playing well with others thing or is the sensitivity on the obc410 simply lower? It's not really a big deal for me since the orange is definitely loud enough as is, I was just curious.