Thigpens' recommendations are that with records with an eccentricity of 1/8" a low mass pivoted arm will be superior.
Dover this has been mentioned many times here and is documented in the ET2 manual. What I am curious about however is that at the time of printing of the original ET2 manual MM’s were in their heyday. MC’s became more popular later and BT adjusted with the 2.5. I am wondering if he was printing an update to his manual, if a heavier mass pivot over a lower mass one would be recommended for MC specifically. Any opinion ?
Fwiw
From my record collection there are idk maybe 150 -200 put aside – they can be seen on the ground in the pic of my listening room. These I listen to on a regular basis.
From this group there is only one record I am aware of that falls in that range of 1/8 inch. This record happens to be one of my wife’s favorites and I use it to ....entice her into the room :^)
My solution to this oddball record was to drill out the hole and spend 30 seconds centering it with my DIY center weight seen here.
http://cgim.audiogon.com/i/vs/i/f/1366423048.jpg
The pressure points are on the outside and there is a washer underneath. Actually various size washers can be used as needed. Mostly however my records are in good shape warp and off center hole wise (meaning not visually noticeable).
Cheers