Vintage Denon Direct Drive Turntable

Lewm,
As regarding to my plinth-less support, I am thinking to add a lining of sorbothane and sandwich between the skeleton base and motor unit to further improve the isolation and resistance to shocks and vibrations from other sources.
I have done another approach to my other turntable "the SP 15" with reasonable success by using acrylic for the plinth material which was not difficult to cut and drill. Also it was aesthetic appealing and was my main concern at the first place. I did think about using slate but it would be prohibitive costly, if feasible for those with deeper pockets. Actually if I were choosing a plinth for my DP80, I would choose slate as my priority though.

My three armed SP15:-

[IMG]http://i44.tinypic.com/1zebas9.jpg[/IMG]

[IMG]http://i43.tinypic.com/14j7rf9.jpg[/IMG]

Kcc123, It's quite possible that the sorbothane liner will work out well, but I have never been fond of sorbothane "feet". One thing to consider is the factors that govern energy transfer between dissimilar materials. At the interface energy will be either reflected back into the energized material or transmitted to the contact material. In both materials, energy is dissipated as heat as it bounces around. There are websites that give constants for different materials and show how to predict the outcome of interfacing one with another. If you want the energy of the motor to be drawn away from the chassis and platter, it seems to me it would be a good idea to choose materials that interface well with the metal of the chassis. That is, you might be best off with what you have now, with the JVC metal ring plinth. Moreover, it might be a good idea to have something heavy and metallic in direct contact with the motor per se, a la Albert Porter's SP10 plinth. (Go to the Soundfountain website to see photos and drawings.)

[IMG]http://i230.photobucket.com/albums/ee15/indypepa/newdenon.jpg[/IMG]

I have owned my DP80/dk300 for 6 weeks now along with a Koetsu SA1100 special edition tonearm. I am running a re-tipped and nuded Denon 103, this rig is my last stand at analogue nirvana and I'm deeply impressed so far.

I am looking at developing a new plinth, for reasons that are discussed above, also as the footers on the dk300 are nothing more than threaded alu blocks encased in plastic with felt attached to the bottom. I'm really interested in a substantial slate plinth, but as kcc123 says, it's cost prohibitive. I'm off to some reclamation yards this weekend to try and source some slabs.

My second option is to go for a massive layered plywood jobbie, with maybe a sheet of SDS isophonon as the top layer, although I feel the slightly textured finish of the sheet may be a concern for coupling to the underside of the chassis. My previous deck was a KAB modified SL1210 and for that I built a solid wood plinth surround (box) that contained an inch of silver sand and granite slab for the deck to sit on, this is also an option, but I really want to go all out for the slate solution, however, getting 4 inches depth along with cutouts, coupling holes and finishing is no mean feat.

I have also sourced some butyl rubber speaker damping compound to apply under the 'skirt' of the chassis.

Look forward to any theories you guys may have for suitable solid or cld plinths.

You can buy a slab of two-inch thick PA slate from any of several sources and have it shipped to you anywhere in the US for a total cost of less than $500, maybe much less than $500 if you don't have to pay shipping. After that you need to find someone local to you with a CNC milling machine that can cut the hole for the Denon to fit. Since the Denon requires a not-too-complex hole that consists of a series of concentric circles, you don't really need the services of a water-jetter to get it done. I am assuming the milling would cost ~$200 additional. I own a proper size slate slab, and I am going to visit a guy who can cut it during the coming week. You can come up with a pattern for the needed cut by tracing the hole in your DK300 plinth, which is what I have done.

Thanks for the reply Lewm. I am based in the UK (Wales) where the world's finest slate comes from (apparently) but it's still very expensive here. Hopefully I can source a decent fireplace plinth or something of similar size. I have a local stone mason who specilises in headstones, so he can help with finishing, just need to find someone to cut the holes.

I have inverted the plinth onto an A2 sheet of paper and traced the cut-outs for the motor unit and tonearm. How are you intending on securing your chassis and tonearm to the slate exactly? I was thinking of perhaps some bore holes with an m5 cabinet insert secured/glued inside.

Please post some images of your slate plinth when you are ready.