So, now that I have been spinning this table for a few days I have a better idea of how the parts work together...
.and the bottom line is well, very well indeed. It has totally transformed the sound. In it's stock form it was tight sounding, with an upfront and not too deep soundstage. Like I mentioned before....The molded pl10 sounded better. However, that fight is now over....The molded 166 wipes the floor with the pl10. Noise floor is much lower and now the 166 does more what a top end deck should do.
The sound is deep, rich and clean. It is now closing in on my wtrp/Benz......and this is with a cartridge that cost under 100. I'm not sure what contributes the most to the improvement, the plinth or tone arm, since I changed them at the same time. My guess is the plinth to arm ratio is 35 to 65. The rega 202 is a screaming value and allows the denon to resolve at its best. The plinth provides a solid foundation and does not transmit much, if anything to the arm or cartridge. Banging on the plinth with the cartridge in the grooves does not transmit anything. Yes, no thud or knocking sounds. Both are worthy investments and has now turned a 35 year old turntable into a modern day player to be reckoned with at its price range and maybe double.
It's not finished, though, and I'm sure there are more improvements to come......new rca jacks...some rewiring.....damping of the bottom of the tpo plate......and tonearm stub and counterweight replacements. These will occur sometime over the next few weeks but for now I am enjoying the ride. This table is staying with me and I strongly encourage anyone to pick up a 166 or one of its model run and have a go at it.
Here is bit more about the plinth. It's made by some guy in Romania. He uses fir....soft wood. I was a bit reluctant to buy it because it is a soft wood but caved after looking at its construction and value, it comes with a nice dust cover, and, after looking at my custom pine fender cabinet thought....what the heck go for it. Anyway, the construction is good....not excellent....but together with the deck it looks great. It is solid and for what softwood gives up in density to hardwood it makes up in mass, which, I believe allows it to have such good isolation properties. Combined with the Thoren's sprung isolation the plinth has better isolation properties than my wtrp. Does that translate to better sound? In the end I will find out but right now it is very good. I could stop with the upgrades now and be happy but I'm going to push it as far a I can go within reason.
More updates to come after I receive and install the remaining parts.