Sota Sapphire

I have an early version Sapphire, ca. 1983, which uses a servo motor. Later versions, or at least most later versions, use a synchronous motor, as I understand it.

I haven't taken the time to dig out my strobe disc, but based on a quick look my Sapphire completes the first revolution in almost exactly the 3.6 seconds Tony cited (I was going to say a tick under 4 seconds before seeing his post). It appears to be nearly up to speed at that point, although perhaps a fraction of a second away from getting all the way there.

Regards,
-- Al

33.3 rpm is about 1.8 seconds per revolution. How do you come up with 3.6 seconds for the bars to stablilize equaling being up to speed in one rotation. I havent bothered to actually try the strobe thing, but it takes me more than one revolution to cue up a record anyway, so its not really an issue on my Cosmos.

Hi Manitunc, since the platter is starting from 0 and assuming linear acceleration and that the platter reaches 33 1/3 rpm at exactly one revolution, then the average speed of that first rotation is 16 2/3 rpm. After the first rotation the average speed will be 33 1/3 rpm. I'm sure your most excellent Cosmos does better than 3.6 seconds if the belt is in good condition.