Best Support For Rega 3

I have a Rega P3 with and Elys cartridge sitting on sorbethane feet on a piece of 1" birch on a built in entertainment center. Sounds good except a bit bright when I crank it up. Electronics are Linn Kinos and Linn Klimax amps. Have had advice from change cartridge to get a better platform to put it on. Was on thick marble, putting it on wood seemed to calm it down a bit. Any advice? Someone has suggested a base made by First Impression Music. Don't mind spending a few hundred bucks but if it's the cartridge I'd like to know. Thanks for your input.