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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

#71

Post by echoangle »

yial wrote: post #9
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?

So really short description, you have 33, 45, and 78 rpm. Most record players are belt drive. Anything that is belt drive usually has some slip / variation (if more familiar to you, imagine the belt drive on a lawn tractor). Many have a finer adjustment to tune the spin rate. +- off of the selected rate. (Perhaps you selected 33 rpm but it’s really spinning at 32) I’m sure someone who knows much more then I do, could…

Is the problem really the slip in the belt drive? I thought its just the motor driving it at a slightly wrong speed.

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

#72

Post by kazinator »

echoangle wrote: post #70
kazinator wrote: post #43

I'm skeptical; you have no idea whether a random song from a record player is in tune or not, without a reference copy of that song from digital media. Is this zeroing in on traces of 60 cycle hum in the recording? Or else, won't it adjust an out-of-tune song to be in concert pitch? (Mind you, that would be extremely useful if you're playing along with the track and don't want to adjust your instrument, or cannot do…

60 cycle hum probably would not work, europe uses 50hz

That's a big enough discrepancy that the program could have heuristics to figure it out, particularly if the record player is in the right ballpark.

Also west Japan is 50, east 60.

The main problem is: (1) there isn't a lot of hum on professionally produced records; (2) but there may be hum from the equpiment itself.

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

#73

Post by criddell »

kazinator wrote: post #55
nickthegreek wrote: post #25

Just put a record on yesterday and my wife said it was playing too fast. I thought she was wrong, then I see this post today! I grabbed the app and gave it a go, 3.5% too fast according to your app. Now I have to figure out how to adjust the damn thing. Really appreciate a free nonsense free app. update: youtube to the rescue. pretty common affordable turntable( Audio-Technica LP60), so I figure I would put the vid l…

3.5% is a lot! One semitone is a bit shy of 6 percent.s It's between 59 and 60 cents: more than a quarter semitone. Exact value: 1> (* 1200 (log2 1.035)) 59.5569212695205 So 59.6 to 3 sig figs. Someone with a good pitch memory of a tune (hearing in their head how it should sound) would spot such a difference. Especially if they heard the tune recently.

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.

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

#74

Post by gchamonlive »

peter_l_downs wrote: post #49

Strongly recommend updating your website to lead with some variation of "This is an offline iPhone app to help you calibrate your turntable's speed, all you need to do is play your records and the app will show you the current RPM" — wayyyyyyy too many words and other nonsense before I could figure out this is what it did. Embed the demo video (the tweet you linked) too! Looks great and if I still used records I woul…

> Let's be real, if this charade of a website was an actual startup, we'd probably wear t-shirts that say...

It's intentional. The app is free. There is a statement about this whole corp mission mindset.

This is the way it is. If people don't like it or push it away from the product, they are not the target audience.

I think this is brilliant. I understood immediately what the app does and kudos for the courage in setting the website the way it is. Was also impressed with the aesthetic of the site.

If only I had a turntable...

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

#75

Post by tiborsaas »

nickthegreek wrote: post #25

Just put a record on yesterday and my wife said it was playing too fast. I thought she was wrong, then I see this post today! I grabbed the app and gave it a go, 3.5% too fast according to your app. Now I have to figure out how to adjust the damn thing. Really appreciate a free nonsense free app. update: youtube to the rescue. pretty common affordable turntable( Audio-Technica LP60), so I figure I would put the vid l…

> Now I have to figure out

I'm glad it didn't continue with where you'll sleep tonight :)

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

#77

Post by dmd »

miah_ wrote: post #51

This is a neat idea. I don't know why it needs to be an app on a phone though. I guess you "know" a phone has a microphone and the setup is minimal and you have a api for everything? It being a phone app leads me to believe the 'no data collected' bit is temporary as all phone apps eventually gobble data to sell. I have an Android so I can't try this out, as its in 'private beta' on Android currently. Would love to s…

Funny, I have the exact opposite intuition as you. It being a totally-sandboxed phone app means I can trust it not to collect any data without my knowledge, without me having to spend hours looking through the source code for some trick I might miss.

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

#78

Post by crazygringo »

egypturnash wrote: post #68

All the turntables in my life as a kid had built-in calibration, in the form of four rows of repeating black/silver squares on the side of the wheel, a light flickering at the mains frequency, and a little dial to adjust the turning speed until the row of squares corresponding to your current combination of 50/60 hz DC and 33/45 RPM appeared to stop moving. It was a very clever trick.

I never knew what the heck those squares were for!

Just thought they were some funny aesthetic choice from the 70's and 80's.

Thanks for giving me the definitive answer for something that has always seemed odd to me.

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

#79

Post by peter_l_downs »

gchamonlive wrote: post #74
peter_l_downs wrote: post #49

Strongly recommend updating your website to lead with some variation of "This is an offline iPhone app to help you calibrate your turntable's speed, all you need to do is play your records and the app will show you the current RPM" — wayyyyyyy too many words and other nonsense before I could figure out this is what it did. Embed the demo video (the tweet you linked) too! Looks great and if I still used records I woul…

> Let's be real, if this charade of a website was an actual startup, we'd probably wear t-shirts that say... It's intentional. The app is free. There is a statement about this whole corp mission mindset. This is the way it is. If people don't like it or push it away from the product, they are not the target audience. I think this is brilliant. I understood immediately what the app does and kudos for the courage in se…

This is a Show HN, so I replied with my feedback. The author explicitly invited this, too, by writing:

> Would love to hear what you think about it!

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

#80

Post by bastardoperator »

gcp123 wrote: post #37

What a perfectly simple app! Going to try this out with my Technics SL1200 mk2 tonight. Thanks for sharing. P.S. Reading comments from a bunch of tech folks trying to wrap their heads around an app for calibrating analogue music playback device is very amusing. :-)

I assume this is for belt driven turntables, not direct drive. I also have a pair of 1200's. Most mixers these days have BPM built in, and before that you had red micro bpm counters and headphone amps to validate BPM. Never once on my 1200's did it read something outside of the producers BPM count when pitch was locked.
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