Others may have more valuable insights than me, but you have what seems to be a fairly well matched analog setup at the moment, and if it were me, I might try out some different MM carts first and see where that got me. Raul posted a thread recently about some carts he thinks are good performers, two of which are MM's. Check it out here http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1173550723&read&3&4&
Should I purchase an expensive phono preamp
I have a Nottingham Horizon TT with the Rega 250 arm and a Goldring 1000 series MM cartridge. This is hooked up to a Pioneer Elite VSX-99 AV receiver that has a built in phono stage. I am trying to improve on the phono stage but I am wondering if there will be diminishing returns going to the more expensive stages. I am considering Lehmann BC, Graham Slee Era Gold V and AcousTech PH-1. I listen to Jazz, Old School R&B and Classic Rock music mainly.