I'm getting there!
Just read up the internet and realised it was a cueing problem. The tone arm jams against the vinyl's edge as the arm reaches closer to the centre. I've found out that the tone arm has a micro-foot which can be screwed to level it. That's that problem sorted now.
The other one about siblance - at eye level to the stylus, there's a hair that's being trailed along the track which might explain it.
This Gyrodec is fing awesome!
Just discovering REM's 'Out of Time' on vinyl for the first time - the cd just don't compare