- 27 posts total
- 27 posts total
I am late to this forum but here is my take on it.....
Synchronous motors are DESIGNED to be constant speed based on supply FREQUENCY.
DC motors have inherently variable speed based EXTREMELY sensitively on DC voltage.
To ensure that a DC motor stays on constant speed, the speed has to be sampled many times a second and "CORRECTED" if the voltage drifts. And, voltage will ALWAYS drift no matter what.
With a sync motor and specially with Valhalla, the frequency is derived from a xtal oscillator and is therefore EXTREMELY STABLE.
Therefore, in conclusion, it is much more difficult and troublesome to adjust speed by continuously correcting it, rather than having a motor which inherently runs at a constant speed by design, especially driven by a xtal oscillator.
The ONLY saving grace of the DC motor may be its quietness. However, the synchronous motor can be made just as quiet by reducing the applied voltage to it and adjusting its phase shift capacitor to be as close to 90 degrees as possible. These are still MUCH easier to achieve in practice than to build a speed sampler and correct the voltage.
Origin Live told me that I may need to help the platter to get rotation started with my hand. If this turns out to be true, this is unacceptable. I was not thinking that my hand would be a crank for the turntable start procedure.I’m the opposite. I always ’help’ my platter get started and up to speed. Otherwise, all the work is done by the belt and motor, or on a DD, by the motor. It causes belts to stretch, and motors to do far more work to overcome inertia, and the heavier the platter (and most think heavy is good) the more work is required. Once at speed, maintaining speed is much less stress on motor and belt. And I don’t think I’m being imposed upon: I’m helping.
Synchronous motors are DESIGNED to be constant speed based on supply FREQUENCY.Supply frequency is not stable nor reliable. I filmed a documentary in a new power station. Everything was the latest tech. Very impressive — until I reached the frequency control room. The "high tech" controller was a guy at a big steering wheel (looked like the helm-wheel on a racing yacht) and staring at a huge meter. 50Hz was the target, and despite his efforts, the meter was always moving — 49Hz, 50Hz, 51Hz — and he would correct by turning the wheel. Sometimes it dipped to 48 or rose to 52. It AVERAGED 50Hz over 24 hours, but with many fluctuations. I hope, but don't know, it's been improved since then...
There are many MODIFICATIONS by LP 12 which can't
be called ''IMPROWEMENT''. Raul ever stated ''if an design is
good why so many modifications?'' My Kuzma Stabi Reference
was without any modification for years. My old LP 12 have had very
simple capacitors network and old Philips motor. Both caused
me to buy OL alternative. If i remember well for 500 euro.
My other reason was the possibility to adjust the speed.
I deed prefer OL version but in comparison with the old
LP 12. But since than there were many modifications about
which I have no idea. So my experience of limited ''range''.
There are numerous reasons why a table might need to be updated...if that is even possible with the design. Not the least of which are improvements in the technology and the ability to retrofit same.
Linn has offered this opportunity with its Linn LP12 over the many years, something that I personally think says a lot for them. If nothing else, this aspect insures the ability to keep the table current with the latest upgrades. How many other turntable manufacturer’s can you say that about?