I'm looking to switch to a rack setup soon. I'm going to buy a crown xox power amp, but am having some trouble choosing a pre. I have a dakrlgass B7K, which I love in front of an amp, but I'm not sure if it functions well as a standalone preamp. I'm also wary of it's clean tones. I was eyeing the sansamp RPM. I was also looking at the verellen meatsmoke preamp, but I'm not sure if I can swing $700. I head the RPM is good for dirty tones, but the cleans suck. Perhaps I can get something that's good clean and just use the B7K for the dirt? Help me out guys. Thank you, happy holidays.