Twizzleshnizzle
500+ Head-Fier
Not really an upgrade to sound. Just a different flavour. The upgrade comes in the functionality (balances connections etc.). Cayin works better with planar as it's not OTL.Looks amazing. Are you using the stock tubes? I wonder how much of an upgrade this would be over my Feliks Echo Mk2.
Both amps have great stock tubes. You could easily have an HA-2A and an OTL amp next to each other. My ZMF headphones without doubt sound better from OTL. My easier to drive headphones such as the Meze 109 Pro sound absolutely amazing on the HA-2A.