Audible wow on Well Tempered TT


My 1987 WTT/TA has been trouble free all these years.  Lately, however, I've noticed some pitch instability...test tones are not absolutely constant.  The belt is a new one from LP Gear.  Anyone have any ideas on what can cause this and how to mitigate?
crustycoot
Justmetoo, You wrote, "slightly out of centre LPs are 'pulling' the stylus back and forth while negotiating the outer grooves, clearly visible as it happens."  I don't know why or how the shape of the stylus tip would make that phenomenon more or less apparent or more or less a cause of wow.  Maybe you are saying that the increased compliance of the new stylus is making the phenomenon more easy to visualize, but you've quoted vertical compliance; that may have nothing to do with horizontal compliance. Off center LPs are an incurable cause of wow no matter what, unless you are one of the few who own the Nakamichi turntable that provided correction for this problem.  We often lament that no other manufacturer ever adopted this adjustment.  And the Nak is rare (maybe because it came out during the eclipse of vinyl reproduction by digital, was expensive, and did not sell well) as a result.
@lewm 
Ehhhh,
OF COURSE! and very much meant, the stylus IS attached to the cantilever!!! 😏 

AND OF COURSE still nicely tracking, following the record groove also! 

The stylus AND cantilever! VISIBLY moves about, deflects visibly, laterally, from the cartridge body, via it's suspension, no doubt. 

This cantilever/stylus deflection, pretty much is in consort of the wow heard - and given due to the described 'tonearm' damping via anti-scate force setting and/or silicone etc. damping trough (this given the high 40cu compliance) 

Please don't expect me to write a Phd theses on this now, please! 😊 

Not THAT hard to understand now, I think. 

If the compliance is a lot less (than 40cu, ~ <= 18cu) - 'visibly' - the tonearm, cartridge en complete, moves just fine with the off-center displacement, with no *visible* defection. 

I hope this will make it a bit more clear, if needs be? 🤔 
Michélle 🇿🇦 
@lewm 

Oh, and one more thing, you are seriously suggesting an e.g. 40cu compliance will only apply vertically ?!? 🤔

Looking/feeling the Ortofon M20 E super or FL super (stylus+cantilever) inserts does not convince me of that take, at all - as it is pretty 'wobbly' left to right, too to bottom... compared to the e.g. ORTOFON CADENZAS BLACK of less than half that Compliance ~ 18cu.
Michélle 🇿🇦 
I don’t know the WT decks from back then. What is the belt made of, I assume it’s not like the current WT decks’.
I had a similar problem with a Townshend Rock Mk2, which uses a round rubber belt, basically a 1/16” cross section O ring. After fitting a new belt there was speed instability noticeable on piano music. The belt was taking a set when it cooled after use. A belt direct from Townshend was the same so I ended up going back to a 10 year old belt. I’ve since replaced the Rock as my main deck but it still gets occasional use for mono, I remove the belt from the pulley when I stop it for longer than the time it takes to clamp another disc.