Turn table speed variation question


I've always found that tracks containing sustained piano notes (chords mainly) seem to highlight the smallest variation in platter speed.

However, I do not notice the same speed variations with sustained notes played on any other instruments.

Works well when auditioning turntables, but a PITA when you hit those older, less than stellar recordings, where the tape machine cause the issue.

Wondered if anyone else had the same experience with a different instrument, or is this specific to the piano.

Thanks
williewonka
Frogman, thank you for the fascinating and highly educational posts.

Best,
Bill
SME30/12

Here is an attempt to show the SME 30/12 with the Sutherland TimeLine. The only other two videos of the TimeLine that I've seen are Halcro's Victor and the one on the Sutherland website.
Thinking about the original post and other instruments possibly used for evaluation, electronic music or electronically generated signals, comes to mind. The pitch doesn't waver on these tones unless it's done deliberately.
Depending on your musical fare, I've heard records with out of tune pianos.

Standard wow and flutter test signal is a 3150Hz tone evaluated on a wow and flutter meter. This might not be a great test for subjective evaluation unless the table needs a new belt, but electronically generated harmonics with dynamic content, might. Offhand, I can't think of a good candidate though.

BTW, my previous referral to KOB being a 1/4 tone off was off the cuff and apparently wrong. The original record is a little bit sharp.
Regards,