I currently have the Ampeg SVP Pro and a Yamaha PB-1 into a Crown XTi-2000. I tell ya, the Yamaha is freakin' impressive as all hell! I used it last night during practice and it sounded beautiful. It had balls with just a tiny amount of dirt but EXTREMELY responsive. It's a great pre! The SVP Pro? It sounds like Ampeg of course but it's kinda difficult to get a straight, clean tone. I love the o.d. I get out of it but it's noisey as all hell and I think I'm having some electrical problems with it. For versatility and clean, chunky tone the Yamaha PB-1 is absolutley outstanding... and I only paid $60 for it!