03-13-08: Cmk
Not so much a cartridge question, rather an SL1200 hot-rod question:
Which would be a better option for modding an SL1200
a) HiFi World's version with modded RB250
OR
b) KAB SL1210 M5G with:
Fluid damper
Outboard PS
Threaded record clamp
Cardas tonearm rewire
Isonoe feet
Some of those options are not mutually exclusive. The HiFi World project 1200 also had the Isonoe feet and an aftermarket mat. I think it would have further benefited from the clamp and outboard PS.
I have no direct experience, but I suspect the outboard PS would have taken away some of the "clinical" sound of the resulting product. I don't have the KAB threaded clamp option, but I do use his rubber grip clamp, and it adds clarity and subtracts both spindle and surface noise.
I also suspect HiFi World's evaluation of the stock tonearm is a tad exaggerated. In my experience the fluid damper makes this a significantly better arm. Kevin's reasoning for staying with the stock arm and adding the fluid damper and rewire is that the Technics' arm's bearings are better and more precise than those of the RB250 and 300, and that a fluid-damped double gimbal design is inherently more stable than a unipivot design. As for bearing quality, Audio Origami's rebuild includes reworking the bearings and lubing them with better, more permanent stuff, and re-machining to correct azimuth alignment. Then there's the matter that the Technics arm has adjustable VTA.
Given how ecstatic the reviewer was with the results, and the fact that this project turntable was compared to a SME 10 and a Gyrodec, it sounds like the platform--inexpensive as it is--bears up to some rather extravagant modifications.
Were I to go for a full mod, I'd first optimize the platform by adding KAB's outboard PSU, threaded clamp, an Isoplat mat or similar, and Isonoe feet.
As for the arm, I suspect that a stock RB250, with dodgy azimuth, lack of VTA adjustment, plastic stub, and standard wire, would not be a clear winner over a Technics arm with Cardas rewire and fluid damper. They'd probably sound different, but I'm not sure one would sound better overall than the other.
Once you install that OL armboard, however, it makes many arms available, some of which should be clearly superior to the stock arm.
Were I to do the Origin Live armboard-based tonearm mod, instead of getting a heavily modified RB250, I'd spring for the extra $200 and move up to the Origin Live Silver arm, which includes all the RB250 mods plus better bearings. Then I'd get Pet Riggle's VTAF mod. I think at this point you would get a clearly superior arm while retaining the advantages of VTA adjustment and easier cartridge swapping--with the Riggle mod, you can simply lift the arm out of its hole and set it on its side to change cartridges.