I have a hand held tachometer from China which I trusted but I discovered a moment ago that there is a difference with the arduino from DIY audio of 0.6 turn per minute.
Measuring turntable speed
Happy Holidays everyone! This has probably been discussed before but I'm of the age that makes me a bit of a Luddite. I have a VPI Scout and SDS. I use "The Ultimate Analogue Test LP" to play the test tone and (at least I used to) the app Dr. Fridrekson(??) had other there. It mysteriously disappeared from my iPad and I can't find it anywhere. What are you using? Thanks!