Help me decide on phono preamp

I have enjoyed my current setup but have decided to try a seperate phono preamp to see what improvements in sq can be had. I have two options I can purchase locally in mind based on my current budget :

Musical Surroundings Nova Phonomena ($400 used)

Lehmann Black Cube SE ll ($600 used)

My current setup is a Music Hall MMF 9.1 TT with a Clearaudio Maestro V2 cartridge playing through the built in MM/MC phono preamp in my Marantz PM - 11S3 integrated amp. 

Any opinions on either of these options?  The built in preamp has excellent reviews. Will either of these alternatives make a material difference or do I need to significantly increase my budget to have a real inpact?

Thanks