Rega P25...upgrade or replace


I've owned this rig for a while now, having upgraded from the P3. While it sounds very nice, it lacks the refined sound and resolution of...say a well recorded HDCD disc on my CD player. Table is stock, used with a Grado Ref. Platinum 1.5mV and Grado PH-1 (tried a ARC phono stage that was lifeless). I'm considering a step up to the Sonata cartridge, and tweaking the table/arm with one or more of the following: machined sub-platter, new counterweight, Cardas re-wire of arm, acrylic platter, Boston Audio platter mat.

Plan "B" would be picking up a nice pre-owned VPI Scout/JMW 9 setup...not sure on cartridge, but most likely the Sonata.

Any suggestions/advice from some of the analog gurus here?

System: BAT VK-300x w/ tube front end, Cardas Golden Cross cabling, CAL CL-15 CDP w/ JPS Digital AC power cord & VansEvers digital power conditioner, Tyler Acoustics Linbrook floorstanding monitors wired w/ Cardas.
hedgehog
Mofi,

I figured that most of them would make a difference, I'm just weighing the upgrade cost vs. an actual new/er table. I don't know if I want to own a $2,200 P25?!

At the very least, the cartridge will need to be replaced. I've also been told that the stock VPI Scout is a considerable improvement over the stock P25. Unfortunately, I don't have a dealer nearby to be able to check it out for myself.
An alternate opinion......I think that the phono preamp is, by far, the largest bottleneck in your system. You can upgrade your deck all day and I do not believe that it will materially effect the quality of the sound. The deck, while not my favorite, is a very capable player and has a decent level of refinement. A nice upgrade would be to the EAR or Gram Slee phono stages, though there are many competent performers available. Just because the ARC phono was not consonant with the sound you prefer does not mean that the phono stage is not a problem. After that, the cartridge could go. The Dynavectors work well on the Rega arms.
As a long time owner of a P25 I can echo MoFi's advice. I have done the Incognito(cardas)rewire. I gained some clarity and solved a grounding issue. Then the E-Z Riser VTA adjuster, I would look at the newer ones now, but that gave me that adjustment. I added the Michel Techno-weight and boom there was bass and the bass was good. I then added at MoFi's advice the Deep Groove sub-platter/bearing assy. and yes the bass was more defined. Than I added the acrylic platter and that seemed to bring the whole thing together. I started out with a Grado Reference, then a Benz- Glider and now have a Lyra Lidian B. I may be stepping up to a Argo or possibly the New Rega MC cart. or the possibility lingers for a new table. But my point is the P25 can really add years to it's life with these tweeks and upgrades.
Thanks, for all of the valuable input guys.

Viridian, I have used the table/cartridge with phono stages from Plinius, Musical Fidelity, VTL, ARC and Classe'. Outside of the Grado, the VTL was the only one better. I have heard great things about the EARs, and I may try one someday.

Theo and MoFi...thanks. Maybe I will tweak around with the ol' P25 a bit. One nice thing is that it can be done a little at time, not requiring large lumps of cash at a time. Theo, who did your re-wire work for you? If you had to pick two upgrades/tweaks, which two would you perform first?

Thanks,
Chris