Firstly, improve the mounting arrangements of the RPM4 and get it out of room corners if possible. get the best out of this and THEN look to upgrade!
I'd agree with Marco on the Nagaoka recommendation, but unless the 681EEE has improved in the intervening decades since I owned and used them, I'd say the Stanton is DULL, DULL, DULL and bland with it, whereas Nagaoka's are lively and bright IMO. There are plenty of vintage test reports I can post as backup to these comments too if necessary The Nagaoka or AT440MLa should liven up the RPM4 as well, by the way, although I don't know what Ortofon is fitted to the Pro-ject..
The Rotal phono stage is very competent, but hardly magic-making as the Croft is IMO. For £350 you could have a complete Croft preamp INCLUDING a phono stage - it would be worth an email to Glenn (or PM to HiFi dave) to find out exactly what the differences are between his baby preamp and the main £700 model. Can the Creek phono stages for sale on eBay be used with your amp? Apparently, someone here (I forget whom I'm afraid) designed it and can help with mods to enhance it further to SE standards...
The Garrard you own - FETTLE IT!!! I'd also look at plinth options, even if you don't ditch the one it's in. The SME is fine for Ortofon OM series cartridges or vintage ADC's and Shures and Johnnie at Audio Origami can re-wire and foam-fill the arm tube for you. I love using SME's, they're so well and delicately made and they sound good with the right cartridge (including their headshell gunk and very light damping).. I'm currently still using an Ortofon M20E Super and it is so sweet and musical without sounding dull and lifeless as so many vintage mm types can. I'm using a CAP210 with it to get the loading right. The VMS models are not as good IMO (I have a VMS30/CAP210 ready to go)..
Last edited by DSJR; 05-09-2009 at 12:37.
Tear down these walls; Cut the ties that held me
Crying out at the top of my voice; Tell me now if you can hear me