What Viridian said and Halcro hinted at. More important is stable speed regardless of groove modulation, as opposed to bang on 33.33 rpm. If a table can stay at 32 rpm whilst tracking any and all passages, then it could probably be adjusted to run stably at 33 rpm, so absolute speed is less of an issue, IMO. I read a very insightful piece somewhere on the internet last week which pointed out that the turntable provides fully "half" the music, as its speed past the stylus provides the horizontal axis of the complex sine waves that represent music, if it were graphically displayed for example with an oscilloscope. The cartridge can only give us the other half, the vertical or amplitude direction. All musical timing must come from the tt. Pretty sobering, eh? Well, I knew that, but I had never thought of it that way.
Turntable speed accuracy
There is another thread (about the NVS table) which has a subordinate discussion about turntable speed accuracy and different methods of checking. Some suggest using the Timeline laser, others use a strobe disk.
I assume everyone agrees that speed accuracy is of utmost importance. What is the best way to verify results? What is the most speed-accurate drive method? And is speed accuracy really the most important consideration for proper turntable design or are there some compromises with certain drive types that make others still viable?
I assume everyone agrees that speed accuracy is of utmost importance. What is the best way to verify results? What is the most speed-accurate drive method? And is speed accuracy really the most important consideration for proper turntable design or are there some compromises with certain drive types that make others still viable?
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- 583 posts total
Quite right Lew. It really doesn't matter if your TT is revolving at 32.4rpm or 33.3rpm (other than pitch)......as long as it it is unwavering! And that article you read was the one I posted by Peter Moncreif of the IAR. It was like a thunderbolt for me. The man is a real thinker :^)......in a field where there are some stinkers :^( |
The turntable speed should be at least as accurate as the tape recorders used to record, master, and playback the tape. Constant speed is "much more" important than absolute speed. Just buy a strobe disc and illuminate it with a light bulb. The 60 Hz AC frequency does not fluctuate enough to worry over. Adjust the speed of your turntable, or AC input (if you have a variable frequency supply like VPI SDS) for the lines or dots to appear stationary or slightly vary around a fixed position. This is simple and more than sufficient. Tape decks are not all that accurate, and do go out of spec. On my VPI TNT the SDS AC line frequency is set within .01 Hz. If your platter is heavy, playing a record will not affect the speed. |
If your platter is heavy, playing a record will not affect the speedWritten by a man who has no verifiable proof. TIMELINE |
- 583 posts total