Stroboscopic disk sets wrong speed for turntable?


Hi all! I am new here.

I have just set up my Clearaudio concept turntable. Unfortunately, the speed of the turntable was wrong so I had to reset it. In order to do this I have used two methods: an iPhone app called RPM; the stroboscopic disk + the iPhone app StrobeLight.
The problem is that when everything is correct at 33 1/3 (both verified with the RPM app and the stroboscopic disk), the songs are playing one semitone lower than what they should. In order to make them play at the correct note, I have to set the speed at around 34 RMP as shown by the RPM app. Also the stroboscopic disk shows that now I am going faster than the 33 1/3, being consistent with the RMP app. How is this possible? Am I doing something wrong or even the stroboscopic disk is not accurate enough? Could it be the StrobeLight app not being an accurate enough light source for the stroboscopic disk? It is just peculiar that both the RMP app and the stroboscopic disk are consistent in saying that I am going too fast. 

Any help is much appreciated. Thanks!
agforte

Showing 3 responses by fsonicsmith

There is nothing  better than the now defunct Phoenix Engineering Road Runner. It was hoped that Sota would re-introduce the product but it seems not at present. The design is not that complicated. A magnet and a sensor and a simple IC chip in a box to a read-out display. One would think there would be a ton of Chinese made cheap knock-offs but nope. 
Strobes are second-best but they almost always waver back and forth. Most platter engravings are slightly off. And then even if you set proper speed at one point in time, there is speed drift caused by motor warming, variations in voltage, and even stylus drag. The combined PE Road Runner and Eagle PSU was unbeatable, both for ultimate speed stability and value. But overall, the importance of exactly precise rotational speed is overstated imho. How else would Rega get away with fast tables for all these years? Mikey is fond of saying "precise speed is job 1 for any turntable". Rubbish. Lack of noise is number one-motor induced, bearing induced, stylus-record induced, et al. And even then, an argument can be made that the white noise associated with vinyl playback is largely why it sounds so good. It masks a lot of evils. I have a longstanding feud with Mikey (not that he gives it much notice other than an occasional solar flare) over this exact issue. Mikey expects ultimate vinyl playback to compete with digital for low noise floor and detail retrieval. I find that to be a waste of time, effort, and expense not to mention an impossible goal and a misdirected one. 
Thank you Peter! I thought it was PBN and not Sota that was coming to market with a similar product. Is it Sota that bought the rights to the Phoenix design but just for Sota tables?
Could you expound on why your product won't display actual speed? Is it so as to not infringe on the Phoenix design? Is the Phoenix design patented or otherwise protected from copying? Certainly the more intuitive the better and I don't see how anything could be more intuitive than displaying speed in rpm to two digits rather than what amounts to a revolution count without being per-minute. 

lewm
6,753 posts
02-26-2019 7:12pm
Clearthink, can you take a step back from the ledge and say why you so detest Phoenix? It’s a serious question, because the products are highly regarded by the vast majority. Thanks.
Just click on his name and review his posts. He has started a grand total of 2 threads and the remainder of his 647 posts are little other than broad sweeping attacks that this or that brand is total junk. His recent "Conrad Johnson is cheap colored junk" post is classic. He's little more than a troll under a bridge. Don't feed him. "Clearthink"? How about "Delusionaldribble".