Turntable with stable speed.

Nakamichi made a TT that corrected for off center holes.

Timeline tested:

Basis Debut
Kuzma Reference
Micro Seiki 5000 (discontinued)
Platine Verdier original (France, discontinued)

All of the Denon direct-drive turntables with quartz-locked motors were very stable. Think DP-57, DP-60, DP-70, and DP-72...

-RW-

I had the exact problem you describe with a Merrill Heirloom table. I could hear the pitch changing irregularly, often as the system warmed up and it drove me mad. I now have an SME 20/2 and never hear this effect. I would imagine any of the more expensive turntables would minimize speed fluctuations.

this is not so simple.

some (older) direct drives were constantly monitoring and adjusting the platter speed thus creating a pitch instability all the time. these models came even from companies like micro seiki. not to mention that some of the excellent measurements of the DD's have to do with some trickery in the measurement method.

there are issues with the string tension in the belt driven TT's as well. the speed is maintained constant thanks to the usually high platter weight. Quality motors make the difference here too.

Hysteresis motors are very stable (empire troubador was among the steadiest tables ever made) but no longer in production. pity

Idlers faced issued in this sector too, as the commonly used eddy current brake was not that precise and heavily influenced by several factors.

so the answer is: go for a good table, without excluding technologies. if you would like to provide a price range suggestions could be more precise