This thread has drifted from plinth choices to general modifications. I have replied to many of these types of threads in the past. See my profile. While slate plinths sure look nice and appeal to the brain's common sense notion that high mass must be better, t'aint necessarily so with the 301/401. I have not heard them all but have heard many. I went with layers of birch built by Russ Collinson. Most Garrard experts will tell you that a sizable birch or similar wood plinth gives the best balance of warmth, isolation, and dynamics.
As I have also commented upon elsewhere, I have three platters for my heavily modded 301, the original, a Classic HiFi solid brass (30 lbs or so) and the Steve Dobbins platter (~8 lbs). The Dobbins platter has a copper top on alloy. I like the Dobbins best. All have their virtues. Liveliness/excitement-original platter. Refinement-the heavy solid brass. Mix of both-the Dobbins.
I use the Classic HiFi PSU, a 10.5 Reed 3P, and my present cartridge is a Lyra Etna Lambda. I have Stillpointe SS footers. I use a Roadrunner to keep track of speed. Brian Walsh does my set-ups. He confirms my sound is right up there. I don't for an instant claim my 301 is better than anyone else's. But it sure makes me happy.
