The current 2015 model is the L-590AX Mk II designed to celebrate Luxman’s 90’th anniversary. As a major evolution of the L-590 AX it features a staggering array of improvements including a LECUA volume control which has been re-enginered for more linear volume attuneation. The power supply is beefed up with larger capacitors and includes a more powerful transformer. The ODNF has been re-designed to deliver silky high frequency extension. All told these improvements allow the L-590AX II to drive more difficult speaker loads and is both the most powerful and most refined 550 to date.