Grand Prix Audio Monaco Turntable

while belt driven tt's have theoretical limitations in speed stability as always it's the execution of a design that is paramount. there are some great belt driven tt's that do speed very well. it's just that the very best direct drive tt's do it better to my ears.

regarding the Rockport Sirius III; there is a very good reason it is no longer made......it simply costs too much to build. so it's particular approach to the speed issue has a level of execution that is unique.

it combines the special pure induction motor with an optical speed controller and servo which regulates the speed. it also uses an air bearing and 55 pound platter combined with vacuum holdown. then throw in an air suspension and multiple layers of mass and isolation and the speed control is allowed to work in an totally isolated environment.

other direct drive tt's might have a cog-less motor and speed correction but no servo to eliminate groove modulation; or a conventional if excellent bearing but not an air bearing, or a great passive suspension but not an active air suspension, or a more modest platter and clamping system but not the heavy platter and vacuum of the Rockport.

OTOH you can buy those other DD tt's as they are still being built.

Mike, I think that it would highly informative (assuming any interest on your part) for you to arrange for a loan of a Monaco from JTinn so that you could then compare the two tables in your system using the same cartridge. This would allow a fair assessment of the Monaco against what I consider to be one of the two best TT's ever built and in a known system of extremely high resolving power. The only caveat would be that you mount the Monaco on a really good isolation base. Any chance that you would consider this?

Thanks Mike for your insight, the Rockport Sirius III is indeed a unique turntable and deserves all the accolades it has received over the years. Andy Payor makes some of the most amazing products in the audiophile business. It also retailed for 3-4X the GPA Monaco. Knowing that you had the Monaco in your system to compare it would be highly appreciated if you could share some of your thoughts.

PS: sure miss reading your old system thread, I much appreciate reading your opinions and experiences.

Henry

All of this platter speed stability (most important in my opinion) and accuracy counts for what when playing an LP that is less than perfectly centred? I would imagine that an LP which is off-centre by even a fraction of a millimetre (which would be many of them) would result in greater pitch instability than any belt driven or direct drive turntable methodology, no matter how well engineered and implemented. Among modern turntables we have engineering solutions that provide some very good answers but sometimes I wonder if we are really asking the right questions. Food for thought.

Aaron

Aaron, I think a math calculation would show you are absolutely correct. But since we all are listening to these imperfect bits of software, the demonstrable (to most of us) differences in sound among turntables shows that we have the ability to discern the more minor (perhaps) distortions related to speed variation even overlaid on the more major distortion created by an off-center LP. Perhaps the difference is that speed distortion created by an off-center LP is "regular", whereas speed variations due to stylus drag or cogging or whatever are irregular distortions, which we find more noticeable.