XL AIR

XL Air turntable is using air bearing compared coventional bearing which allows improvement in two important  paramethers in turntable design.
Air bearing  have almost zero friction and thus no vibrations in bearing itself thus eliminating noise reaching cartridge.
Second advantage with properly designed  air bearing ( not just simple floating on air chusion) is higher load.
Total mass of  rotating platter is  44 kg making it more imune to cartridge drag which slows down any platter regardlessof mass and drive. The top  platter- same as in XL DC turntable ( 22 kg) is a sandwich construction of aluminium and acrylic plates screwed together in a  pre-stressed form to damp all unwanted vibration. Lower bronze platter ( 22kg) is cast and gives good damping properites.
Air bearing requires for function compressed air which is supplied  from air supply.
Air  supply consist of  compressor and air filters. See for details in this manual elsewhere.
Turntable's air bering actually  consists from two  bearings surfaces. Top surface carries vertical load while cilyndrical hole carries horiontal load. Air bearing has a shaft of 31mm and trust plate of 60 mm. 
Air bearing surfaces are made from porous carbon thus having milions of small holes to let air pressure  out. This creates more uniform pressure inside bearing's gap of 5 microns with 4bar pressure  thus making air bearing  stiffer with zero movements.
The base holding air bearing  is made from two pieces  of solid brass which are clamped together having good damping properties.