Turnable database with TimeLine

01-19-14: Peterayer
...If the result is truly as you describe, do you think Syntax would have posted the video for instant criticism?

Could you explain how you conclude that it is the effect of cogging from the same video evidence, especially since Syntax has explained that the effect on the dash line is different when actually observed by the naked eye?

I have taken about five videos of my turntable and the quality of the laser dash appears different in each one depending on lighting, camera angle to the laser dash, distance etc. It is clear to me that the video evidence with an iPhone is far from a perfect method and I think the Micro video was taken with a SLR still camera that also does video.

I did load my very first video at youtube now, the one in the darkness. That one is the one where I thought it is probably too bad from the quality for this Datbase, but here it is clearly to see, that the laser gets the mark in every rotation and another proof of the limit capability of my pocket camera (Canon IXUS) is seen when the Timeline spins and the laser sends the light in the rotation, when the camera get it, it is round of course, but not sharp round, a little bit like an egg from the color light.
Anyway, I saw the original Sutherland video, any video from your thread is easily on par with it. Even in the Sutherland video the length of the laser is not always equal in every rotation but after few revolutions it is always in the same area, too. You got it exactly right when you wrote about the camera recording ability. In reality it is even more clearly to see.

Micro Seiki RX5000 + HS80 Sutherland Timeline

I had a chance to experiment this evening. I used some rubber shims to constrain the sub chassis on my turntable in the horizontal axis. My Sota has the motor fixed on the main chassis while the tonearm and platter float on the sub chassis. First, I put on my test record to check speed with the iPhone app. Speed was 5 Hz high. So belt tension must have changed. I tried to keep the sub chassis in a neutral, level position. I adjusted speed and checked WoW & Flutter with the app. I saw right away that the FFT waveform is a clean sawtooth pattern now. Before the sawtooth pattern had a lot of hitches in it. I think this is already an improvement. Speed is within 0.025%. That is an order of magnitude higher than Peter's turntable; but pretty good I think, for an open loop motor. The timeline laser mark would move around 10X faster on my table than on some others. WoW & Flutter measured 0.02%/0.03%; typical.
Listening: First, I tried "For Duke". This is a technically near perfect direct to disc record and good music too. Rhythm and Pace seemed about the same to me. The bass seems cleaner and sharper. Should I expect that to be the case?
Next, I put on Beethoven's Appassionata. This is another direct to disc cut at 45 rpm. Sounded fantastic as always. Very powerful. I was hearing some micro detail that I had not heard from this record in years. eg. I could hear the pianist take in a breath just before hitting the keys. Would you expect to hear more detail? Again, I think the lower registers of the piano had more power.
I think overall it is an improvement. It was clearly seen on the iPhone app. So next step for me is to come up with a way to constrain the horizontal axis and leave the vertical axis free.

I just played "Muddy Waters" Original Master Recording. He convinced me. The rhythm and pace was obviously better to me playing this record with the horizontal axis constrained on my turntable. Plus, his voice on the peaks did not break up. I would have never attributed that to speed variation; but I just heard it with my own ears. I would have posted this sooner but when Muddy Waters is playing, I'm glued to my chair until both sides of the record have played out.

Tony, Those are very interesting observations. As you may know the horizontal movement of the SME upper platter is also constrained with paddles in silicone in the towers. The vertical movement is less so I think due to the direction and design of the paddles. What you have done with the rubber shims may have a similar effect.

Do you happen to know if the last time you played these same cuts whether or not the speed was off by that 5 Hz? I ask because I listen to Muddy's Folk Singer at 45 RMP and I just cleaned the drive and platter pulleys and my rubber belt with lighter fluid and reversed the belt as per SME recommendations and measured the speed. It was off by a fair amount relative to the last speed check. I had to click the speed buttons about 6-7 times (<1Hz per click) and listened again and heard similar improvements to what you describe.

So, my point is that what you are hearing may be either a result of the restriction of horizontal movement, the correction in speed, or a combination of both. But is sounds like things are definitely improving.

Yes, my speed was within 1.5Hz of 3150Hz before. One thing I can do is recheck speed after I remove the shims and see if it shifts down. The other thing that I found last year with the iPhone app was that the tt must run for a couple of minutes for speed to settle in. I don't know if the motor must warm up, the electronics or the platter bearing lube.