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Show HN: I made a free app to calibrate your turntable by simply playing a song

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Re: Show HN: I made a free app to calibrate your turntable by simply playing a song

#12

Post by hnlmorg »

CaptainOfCoit wrote: post #6
echelon wrote: post #4

I'm not an expert on vinyl. The only record players I've interacted with have only had two speeds. Do most of them do variable spin rates? How frequently do the rates get out of sync? What causes it? Do they vary on an album by album basis?

> I'm not an expert on vinyl. The only record players I've interacted with have only had two speeds. Do most of them do variable spin rates? Lots of turntables have variable speed, DJs can tell you more about it :) > How frequently do the rates get out of sync? What causes it? Do they vary on an album by album basis? When you're DJing, one of the main things you'd deal with, is making things be in sync, one way or an…

I don’t think this would be aimed at DJ turntables. It doesn’t matter if those things drift because you’re never playing anything locked in at a specific RPM.

Plus DJ turntables tend to be direct drive, which should be pretty consistent. Where as consumer record players tend to be more belt drives. And I’m assuming those belts can stretch with time?

Re: Show HN: I made a free app to calibrate your turntable by simply playing a song

#14

Post by tpurves »

echelon wrote: post #4

I'm not an expert on vinyl. The only record players I've interacted with have only had two speeds. Do most of them do variable spin rates? How frequently do the rates get out of sync? What causes it? Do they vary on an album by album basis?

Yes, it turns out that it is rare for mass-produced mechanical devices like record players to spin at exactly the rate they are supposed to (eg 33.3 or 45). Or they can drift put of calibration over time. Often they will be a few % off or worse for really cheap players. Usually there is a way to adjust calibration by turning a small screw someplace on the machine.

Re: Show HN: I made a free app to calibrate your turntable by simply playing a song

#18

Post by gaudystead »

I'm just here to say that I enjoyed that intro you gave to the website, and although I hate unitaskers in the kitchen, that intro helped to remind me of the magical wonder of them in the early days of "The Modern Smartphone".

Cool app and thanks for sharing! :D

Re: Show HN: I made a free app to calibrate your turntable by simply playing a song

#19

Post by datpiff »

franky47 wrote: post #7
patrakov wrote: post #5

Does it rely on the fact that music has a concept of notes with well-defined frequencies and that there is no such thing as 216 Hz (must be 207.6 or 220 Hz) when the music is played on a properly tuned instrument? Or does it use other heuristics?

A "properly tuned instrument" still requires a base frequency (usually defined for A4). Whether to use 440Hz or another slightly different frequency is a fun debate to get into.

Older recordings on analog media also can have timing error at the recording stage or duplication stages.

Re: Show HN: I made a free app to calibrate your turntable by simply playing a song

#20

Post by rufus_foreman »

echelon wrote: post #4

I'm not an expert on vinyl. The only record players I've interacted with have only had two speeds. Do most of them do variable spin rates? How frequently do the rates get out of sync? What causes it? Do they vary on an album by album basis?

DJ turn tables have a pitch fader and lights for calibration: https://www.youtube.com/watch?v=KbdK94vl_Bs.
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