So I got a newish Ampeg BA210v2 combo today, it sounded great in the store when I tried it out with a Sterling SUB. I got home and plugged my Sterling Ray 34CA in and it still sounded fantastic but only when I had the -15db switch disengaged. When the -15db switch is engaged it's super quiet. I almost have to turn the volume knob past 12'o clock to get any real volume out of it. I know it has to be the pre-amp and possibly the pickup. It's not the ampeg because I've noticed this with other 34CA's before. I've heard of other Sterling users here on TB changing out the pre-amp and pickups with great results. I've been looking at the Seymour Duncan SMB-4d. It sounds great and is perfect for my style (Iron Maiden, Rush, prog rock). I don't know much about pre-amps though. What do you guys recommend?