Turnable database with TimeLine

I'm not sure it has been confirmed that the newer Timeline devices have 6 flashes per rev. At least the ones everyone is using seems to have just one flash per rev. Regarding tachometers: most today and even the one in your car uses either optical or hall effect sensing devices. They are not mechanically linked. The accuracy is dependent upon the precision of the encoder ring. Good data capture for micro variations in speed would need to be in the 40kHz range (two times max frequency response of a record), at least. That is several orders of magnitude beyond even 0.3 seconds.

Since the timeline is equipped with only a single laser, it can only produce one reference point per revolution that can be measured against any subsequent revolution. If you want to increase the sample rate, you would need 6 separate lasers flashing once every 0.03 seconds; not a single laser flashing 6x per revolution.

Tony and Brf, I hate to be wrong, but I see your point(s). I saw Brf's point in my own mind, shortly after my last post. Most servo-controlled DD turntables have some sort of platter speed sensor, optical or otherwise. One could probably tap into the output of that data stream to get a continuous read-out of speed stability. That may be what Denon did in order to produce the figure shown in their ad copy for the DP80, which I described above.

Henry, I don't think Syntax's post about the Kuzma was so provocative. As I noted, the fact that the Kuzma was a little fast (or slow; I cannot recall) is not so important as whether it was stable in speed, because a decent motor controller could probably bring it back to exact constant speed, if the error was also constant. But he never responded to my question in that regard. I am not a "Kuzma guy", but I would imagine they have a recommended motor controller for their better models, such as the Reference.

If you want to see the effect of stylus drag, you could ask Ron to make a timeline with 6 different lasers firing once every 0.3 seconds. Take a video camera and record one reference spot on the wall. When playing back the footage, increase the playback speed and you should see how much the speed varies.

The biggest argument against using the timeline is that only measures average speed per revolution. The trick is to increase the sample rate to more than once per revolution.

I have just learned that the TimeLine flashes 8 times per 1.8 seconds or 8 times per one revolution. That is why there are eight laser dashes around the room at all times. I had thought it was six. So yes, if you are looking at one dash near the turntable being tested, that one dash is flashed once per revolution as there is only one laser.

Mr. Sutherland could clarify and confirm this if he joined the discussion.

The other criticism that some have raised is the weight of the unit itself. For a low torque motor, if the TimeLine weighs a different amount from the owners clamp, that might effect the speed results. Less critical for a high torque DD motor that could deal with the added or less weight.

I'd like to see more videos added to the database.