What is a SUPER nice headphone to pair with this amp. Currently the Focal Elex is my best set. Listening right now with the Cavalli LCX + SDAC. Not too shabby. If I wasn't such a gearhead and OTL fan I could stop right here and be eternally happy. Love the Sennheiser HD6XX, too. Not quite as good as the Elex but easily as enjoyable.