Hi all. I already have topping dx7s and currently pairing it with hifiman sundara and audio technica r70x. The current issue that i have is the headphone amp output impendance in dx7s is really high (10ohm), so i can't use my iem, avoiding to destroy it. I want to upgrade to the new topping dx5, but it doesn't have balanced amp (only balanced dac). Should i buy topping dx5 or still use the dx7s for dac and buy topping a90(old version) instead? The price of topping dx5 and a90 is roughly the same in my country. I'm planning to buy hifiman arya in the future. Does the topping dx5 capable to drive it? Thanks