I have a DX3 Pro+ and it’s not bad, but Topping is not particularly known for “fleshing out” anything. I would contact Apos Audio and ask their advice. They sell Topping and a lot of other headphone amps, so they might be able to steer you in the direction you’re looking to go.
Would a Topping A90 or A90D be a significant upgrade from the A30 Pro?
Have been thinking about upgrading my headphone amp, which is a Topping A30 Pro. It's a pretty good amp for its price, driving my LSA HP2 headphones (got these from Underwood HIFI several years ago--I think they're made by Kennerton), delivering decent bass and excellent detail and resolution, though for me, just a bit clinical. I'm wondering if moving to an A90 or A90D would make any difference, or should I look elsewhere for something that fleshes out the sound a little more. I'm not really a tube guy and have no need of a built-in DAC. Looking in the sub-$1K range, new or used. Recommendations gratefully received. Thanks