Live data from Hacker News

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

grooved.okat.best

191–200 of 239 posts

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

#191
post #169

Random though from non-vinyl-aficionado here: Is there an easy way to temporarily leave a mark (and thus a sound) on the surface of the record, so that you can easily measure the time of each revolution without damaging the record or the needle? At first I thought of a small square of scotch-tape, although I expect that might "catch" and damage the stylus. Perhaps blu-tack? A big water droplet?

There are weights with strobe patterns that you can put on.

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

#192
post #83

Earlier quoted context omitted.

Correct. That was often done when mastering with tape. Record at one speed, playback at another to make it sound more "lively." There are songs that were sped up that way anywhere from 25 to 40 cents. It's another reason why live music so often doesn't sound like the recording. When using digital mastering, you can also adjust the playback speed, but you can correct the shift. You get more "liveliness" without the sh…

What are cents in the context of playback speed? Hundredths of an RPM?

A cent is a factor of 2^(1/1200). There are 1200 cents in an octave, which is a doubling in frequency: if we have 1200 of them, 2^(1200/1200) = 2^1 = 2.

Lisp-wise:

  2> (exp2 (/ 1200))   ;; exp2 is courtesy of ISO C 99
  1.00057778950655
So, it is a .0578 percent change in pitch, or determiner of pitch like record rotations speed.

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

#193
post #83

Earlier quoted context omitted.

So many recordings (especially before 2000) seem to be sped up a little. I can’t tell by listening to the song but when you try to play along with a guitar, it sounds terrible. Sometimes it helps to find a live version on YouTube.

Correct. That was often done when mastering with tape. Record at one speed, playback at another to make it sound more "lively." There are songs that were sped up that way anywhere from 25 to 40 cents. It's another reason why live music so often doesn't sound like the recording. When using digital mastering, you can also adjust the playback speed, but you can correct the shift. You get more "liveliness" without the sh…

A bunch of the High Voltage-era AC/DC stuff was this way, IIRC. It's really awkward to play guitar along with the songs in question unless you painstakingly match the goofy tuning of the song, or adjust the pitch of the song first.

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

#194
post #167
post #95

Earlier quoted context omitted.

That's one of the reasons you'd put your best song on side A, song 1 and your 2nd best song on side B, song 1 - you got the most detail on the outside track. I remember seeing an interview with Led Zeppelin quite a few years back where they were claiming they knew they'd have a smash hit with Stairway to Heaven. Which was funny, because I remembered then seeing an interview several years before where they said it was…

I’m not sure about this. Thriller (by Michael Jackson) is one of the biggest pop songs of all time. It was also the fourth track on the A side. Bohemian Rhapsody (another one of the best selling singles of all time) was the fourth track on the B side. Those are two examples off the top of my head. If you give me a bit of time to put my kid to bed, I’m sure that I’ll find many more.

What you've just learned is that pop producers are not in tune with what's good. It's a hard lesson to learn.

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

#195
post #133
post #53

Earlier quoted context omitted.

Are there really "standard" BPM? As far as I know, most music production is just "whatever tempo the band feels like playing." I haven't been in a recording studio, though, so maybe a use of a metronome is more common there?

In some countries there are legal and illegal BPMs, e.g. according to [0] only the BPM range from 80 to 116 is legal in Chechnya. [0] https://www.npr.org/2024/04/09/1243632570/chechnya-music-ban...

Adam Neely did a good video[1] showing just how silly it is.

[1] https://www.youtube.com/watch?v=Q811R6YsM0s

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

#196
post #191
post #169

Random though from non-vinyl-aficionado here: Is there an easy way to temporarily leave a mark (and thus a sound) on the surface of the record, so that you can easily measure the time of each revolution without damaging the record or the needle? At first I thought of a small square of scotch-tape, although I expect that might "catch" and damage the stylus. Perhaps blu-tack? A big water droplet?

There are weights with strobe patterns that you can put on.

I know you can buy strobe mats/discs and view them under a precisely flickering light (sometimes fluorescent lights with the right power-grid frequency) but I guess I was trying to think of something one could use in a pinch that wouldn't involve a separate purchase of things beyond household items. (Excluding the smartphone, which I assumed would be ubiquitous.)

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

#197
post #137

Earlier quoted context omitted.

Unfortunately a lot of mid-range tables nowadays don't have the strobe (mine included), most likely for aesthetic reasons... Even just looking at online shopping right now I only see a handful that do have it. As for being skeptical, good! That means I'm doing something great according to Clarke's third law. You can see me testing out the app on multiple records here: https://twitter.com/OKatBest/status/1795453042994…

Building a "strobe" is just a matter of putting an LED, some diodes, a resistor, and (optionally) a transformer together. The idea is that the LED reaches peak brightness (and darkness) at twice the line frequency, just as ye olde fluorescent tubes did. (Or: Skip the extra diodes and have it work at 1x line frequency. I'm not your boss.) After that, just print a strobe disc and use it.

Or even simpler, use a Neon bulb. or even a Fluro light.

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

#199

So here's another method that doesn't rely on the song being detected or even a song at all: The gyroscope on your phone is accurate enough to measure RPM to about the first decimal place at 33 1/3 - 45 rpm's just by placing your phone on the turntable flat and letting it spin.

[deleted]

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

#200

Cool idea but for a surprising reason I don't need it. Towards the end of the classic era of Japanese hi-fi, even mid-fi turntables out of Japan made this app superfluous. There were quite a few "quartz locked" models which offer great speed fidelity without having to muddle around with anything. As an example, the Technics SL1400 Mk 2 is a quartz locked, direct drive table that has a little window so you can see the…

You talk like belt drive turntables are something new. Most people had belt turntables.

Direct drive and stroboscopic quartz are only a must for djs.

Post reply on HN