[WGH]

I found a couple of turntable apps that are free, very useful and fun.

Bubble Level by Gamma Play - everyone knows your table should be level, this app makes it simple.
https://play.google.com/store/apps/details?id=com.gamma.bubblelevel&hl=en_US

RPM Speed & Wow by Andrea Martignano - find out how your used or expensive table is running, this app confirms you need (instead of want) a new table.
https://play.google.com/store/apps/details?id=com.AM.AM.RPMSpeed&hl=en_US

I put my Harman Kardon T55C to the test. I bought the T55C in 1985, 34 years ago, it has an adjustable speed control along with quartz lock. As I suspected, when the quartz lock is on the speed and wow numbers are much worse and easily heard, the quartz lock has been off since 1986. The table has the Van Alstine designed outboard power supply and all the other tweaks from his Audio Basics newsletters.

The arm picks up and the table turns off at the end of an album, great for late night listening.




Perfectly level where the cartridge tracks.



33.34 RPM + 0.01%
Wow: 33.29/33.38  +  0.11%
         -0.14%/+0.14%



How does my table compare to yours? I'm curious.

Wayne
 

[S Clark]

I've found that when using a phone app for rpm, use a counter weight (second phone is perfect).  On a couple of my tables, having the weight of the phone off center causes a variation. 

[WGH]

Great idea, since I only have one phone I used a kitchen gram scale and a bag of raisins and the wow numbers didn't change. Putting the phone in the center on top of the weight works too but the numbers never get any better.