I've got a WT Classic with the tonearm rest that ends in a cylinder (see the photo). That cylinder has a hole with what looks like a hex socket at the bottom so you loosen and tighten the arm rest for adjustment. Does anyone know what size hex wrench this needs? I've tried all the SAE and metric wrenches I have, and I can't get any of them to engage with this socket. Any tips would be most welcome.
