I think one reason that A10 has the sound like E series may be the engineer who creating this is the same person who makes the E series. I met him at the launch event in Thailand where he also showed the circuit boards of the old E or S series and A10 circuit board.
From the side I saw. Both of them have almost the same component except the amplifier section that A10 use POSCAP for removing noise from power source.
As expected by me a few pages back,,,disappointing to say the least