D90/A90 is 18 months since released and DX7 Pro+ it's new and also not cheap. We normally get (from Topping and SMSL) better performance from newer products at same or cheaper prices, so I think it's normal. I've compared several DAC's SMSL D300 and M500 MKII and Topping DX5, DX7 Pro+ and E30. I...