Halcro, IMO, no one has proven anything until someone who has an excellent plinth can tell us that his dd tt sounds better without it. Even then, the result is subjective. Banquo has it right in that respect.
Banquo, I join in those who are glad you have found competent local help. Can you divulge the name of this person? Others in your area might benefit.
I have a local friend who owns a very successful machine shop. They actually make scientific instruments, but at his home he has every machine tool you can imagine, including a computer-operated mill. He has helped me already making odds and ends for my tts, and I am sure I can enlist him in making something to serve as a no-plinth. (He is basically retired, has hired someone else to run his business, just sits home and collects money.) I am thinking along the lines of the Grand Prix Monaco or the Micro-Seiki 1000DQX, basically a frame that holds the chassis firmly in place with three outward going "legs" upon which one can mount arm boards that are therefore coupled to the structure. Brass and alu in combination might be good structural elements. You can buy nice blank slabs and/or rods, etc, of either on-line for reasonable prices.
On coupling tonearm to bearing, perhaps I misspoke. It would be better to say that I think the tonearm should be coupled to the chassis. Do I need documentation for that idea? About 99% of all tts ever made provide that sort of coupling, some better and more emphatically than others. Oddly, all of Kuzma's lesser models do it that way; only the Airline system does the separate pod. Plus there are a few other high-price entries that also use pods to mount tonearms. I don't like the idea. Regardless of gross movements that could screw up alignment, if there is any chance that the arm pod will be subjected to vibration or resonance that is not also simultaneously experienced by the platter and bearing, then there will be motion of the structural center of the tonearm (the pivot) with respect to the LP. How can that be a good thing for a cartridge that is trying at the same time to trace a groove in an LP? I think the tonearm pivot (in the case of a pivoted arm, of course) and the platter/LP should move as one entity only. That's my story, and I'm stickin' to it. But this is theory we are arguing, not the idea that any one person's system that employs a separate arm pod could or could not be pleasing to the ear.
