Re the air cooled 400w spindle ...I've presently got a 300W version & whipped the fan of it....it's stupidly quiet (but obviously I can't run it for long!)

Yeah, your new/improved spindle is way too big for my modest machine.... 'on the move' is actually London (I was about to move to Dorset but it all went pete Tong - still might), but nevertheless, thatnks for the offer but it's a little bit too far to come & have a listen.

Perhaps I'll just pony up for a VFD & just run the spindle at lowers RPMS if the noise is too prohibitive.....