Lew,
The record/platter interface seems to have so many different factors, experimentation is required, but then we have to take into account things like the sound of a particular cartridge. Assumptions can also be a problem. What works for one record might not be so great for another?
It seems that reflexing or using a vacuum changes the natural resilience of the vinyl and the way the needle is reflected off the groove. These two approaches are often thought of as a positive, but at what point does it become negative, and what kind of surface is under the record? I think using a weight and periphery clamp does the same thing, perhaps more predictably than guessing how much force to use when reflexing a record.
Because a metal platter or mat is harder than vinyl, and the mechanical match up is the opposite of a compliant mat, I would think it would be easy to make erroneous assumptions. It would be mandatory to immobilize the record anyway so you could vary center clamp weight or amount of reflex. Are there metal platters w/vacuum? You could even add weight to a periphery clamp. I doubt if that would help, but you tell me.
A compliant mat is like damping. A thick rubber mat supplied with inexpensive tables is generally more forgiving, but overdamped, smeared, and with less resolution. A very thin compliant mat like some felt or Jico thin one, seem to be the right damping for a metal or glass platter. I had an LP12 years ago and I used it with the felt mat.
The Pierre Lurne' approach is to dissipate rather than dampen, with tonearm and platter. In this respect he's probably the most copied turntable designer. The problem with dissipating vibrations is, where do they go? A hard platter/mat should be efficient transmitting, but where do they get reflected and do they come back?
My approach just copies Lurne'. Lead is very good at slowing vibrations.
Regards,
The record/platter interface seems to have so many different factors, experimentation is required, but then we have to take into account things like the sound of a particular cartridge. Assumptions can also be a problem. What works for one record might not be so great for another?
It seems that reflexing or using a vacuum changes the natural resilience of the vinyl and the way the needle is reflected off the groove. These two approaches are often thought of as a positive, but at what point does it become negative, and what kind of surface is under the record? I think using a weight and periphery clamp does the same thing, perhaps more predictably than guessing how much force to use when reflexing a record.
Because a metal platter or mat is harder than vinyl, and the mechanical match up is the opposite of a compliant mat, I would think it would be easy to make erroneous assumptions. It would be mandatory to immobilize the record anyway so you could vary center clamp weight or amount of reflex. Are there metal platters w/vacuum? You could even add weight to a periphery clamp. I doubt if that would help, but you tell me.
A compliant mat is like damping. A thick rubber mat supplied with inexpensive tables is generally more forgiving, but overdamped, smeared, and with less resolution. A very thin compliant mat like some felt or Jico thin one, seem to be the right damping for a metal or glass platter. I had an LP12 years ago and I used it with the felt mat.
The Pierre Lurne' approach is to dissipate rather than dampen, with tonearm and platter. In this respect he's probably the most copied turntable designer. The problem with dissipating vibrations is, where do they go? A hard platter/mat should be efficient transmitting, but where do they get reflected and do they come back?
My approach just copies Lurne'. Lead is very good at slowing vibrations.
Regards,