Need to pick my fellow Forum friends' brains before I turn to the Support.
My vintage, olive set (72 / HiCap / 250) was re-capped in October 2016 and has been a joy to listen to. It's paired with Quad ESL-63s.
I use it every day, as my office set.
During the last 2-3 weeks I noticed that every second or so day, NAP 250 'mutes' itself overnight. Unplugging it, waiting for the caps to discharge and powering it up again helps.
Any theories what may be causing this?