My CV D-9 surrounds are all dry rotted,.....I push the red surround, it just lets my finger push right through, crumbling slightly around my finger.
My old MTX - AAL 154’s have foam as well, but are still working, no dry rot, no crumbling at all,....still bounce back when slightly pushed into.
The old BIC V830 are butyl rubber surround, they are still like new.
A extremely light finger rub of oil every couple years since the very early 2000’s on the rubber surrounds has worked great, since the first carnation of synthetic oils. The stuff is great. Turntables, any moving part anywhere.
My old MTX - AAL 154’s have foam as well, but are still working, no dry rot, no crumbling at all,....still bounce back when slightly pushed into.
The old BIC V830 are butyl rubber surround, they are still like new.
A extremely light finger rub of oil every couple years since the very early 2000’s on the rubber surrounds has worked great, since the first carnation of synthetic oils. The stuff is great. Turntables, any moving part anywhere.