Morsiani TT/Tonearm
Thanks much Twl. I am trying to learn more about turntable and tonearm design and the engineering philosophy of designers/builders in order to educate myself before I jump off the deep end into vinyl. I discovered the link to Morsiani on the Audio Consulting website (itself an interesting read) and was intrigued by the Morsiani stuff. I asked for some info and Carlo Morsiani sent me a doc by email VERY quickly (30mins later?). From what I gather from his email, an order would take a LOT longer to fill. From what you and others have written here and on AA, I have pretty much committed myself to the high-mass concept. I am very interested in the Teres product and the similar Redpoint/Galibier designs as well - partly because of the fundamental simplicity of the concept. Can you suggest any other sources of turntable-design-related info and ideas, especially about tonearms? Thanks, Travis |
Hi Travis. The best route to find information on just about anything these days, is a thorough web search. I use Google primarily. It takes alot of sifting and reading, but that's the way research is. And also, you have to be well-grounded enough to know which opinions are wacky and which are good. I also like the high-mass, unsuspended turntable designs, but not everyone prefers them. In my opinion, the quality and precision of the main bearing is paramount, then the drive system, which includes the proper mass of the platter(along with a smooth motor) to keep speed control very consistent. Then, again, the platter mass and material to properly deal with vibrational control, and finally the plinth construction. Ideally, all of these items should be superior. It is critical also, to have no relative movement possible between the platter and the cartridge tip, so there should be no rubber or soft materials that allow any movement in the "energy loop" from the platter surface, down through the main bearing, across the plinth to the arm mount, and up the arm to the cartridge(the cantilever has movement, but it is producing signal when it moves). This should remain a "closed loop" system with rigid characteristics. The key elements that would normally allow unwanted movement are the tolerance of the main bearing, and the tolerance of the arm bearings, and of course we want both of these to be as minimal as humanly possible. Everything else should be as rigid as a rock. If there is going to be any isoation or absorptive materials in the design, they should not be in that "loop". That is the basic concept of turntable design. Many builders vary in suspension or non-suspension, and materials and mass, but they will all have that closed "energy loop" if they are going to be any good at all. You may consider air bearings to violate this rule, but they are just as rigid as steel bearings when they are at their proper operating characteristics. Maintaing the unmoving relationship between record and cartridge tip is how information is correctly retrieved from the record. |
Thanks again Twl. I think the "closed loop" explanation is eminently sensible - makes perfect sense (which begs the question, how does one deal with warped records?). I think I will spend some time googling around and see what I can find. Sorry about the link error above, the correct link is www.audio-consulting.ch. |
Travis, the warped records don't really change anything in the "closed loop" except that they are elevated off the platter somewhat in the area of the warp. Everything else remains the same, since the tonearm will move up and down with the warp, but still have its rigid coupling at the bearings. The bearings are actually a rigid coupling that allows movement. At least to the extent of the small tolerances of the bearings. Unipivots have no clearances in the bearings at all. But they may suffer from azimuth movement. When I said "rigid" I didn't mean to imply "non-moving". The assembly can be rigid and still have the needed planes of movement to follow the record. |
