I currently own a Marantz SR7011. Around March I was considering upgrading my mains with a pair of Sonus Faber Venere Signature S’s. They are 4ohm, and have a sensitivity of 90db. In my current setup I have the SF 2.5’s which are 6ohm, I have no concern that the Marantz can drive them. I know theoretically the Marantz can drive the Signatures, but I want to make sure I am getting the full dynamic range of these speakers. Could anyone give some suggestions to what amp would be good without breaking the bank? I have been reading a ton of stuff in this forum and others, but am not sure. I know Monoprice has the new monolith series, but I was curious about other options as well. Would Crown pro-amps work?