Modi 2 for Audioengine A5+?

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Modi 2: Improve Any Computer’s Sound
Modi 2 plugs into virtually any computer—Windows, Mac, popular Linux distros, Intel Chromebooks, as well as iPhones and iPads. Just connect via USB and go with no drivers in Standard Mode, up to 24/96 output. Switch to Expert Mode (and install Windows drivers) for extended high-res capabilities to 24/192.

Modi 2 Uber: The Complete Mini-DAC
Honey, I shrunk the Bifrost! That’s the idea behind Modi 2 Uber. Like Bifrost, Modi 2 Uber offers USB, Toslink, and RCA inputs, each individually selectable via a front-panel button. It also has a more sophisticated analog section, with DC-coupled output. And, it’s ready for all sample rates, from 16/44.1 to 24/192.

Modi Multibit: Unique Multibit Architecture and Digital Filter
Modi Multibit is the most affordable multibit DAC with a modern architecture—from any manufacturer, from any country in the world. Featuring Schiit’s unique closed-form digital filter, and using the same Analog Devices AD5547 multibit DAC as Bifrost, Modi Multibit smashes the high-price barrier in multibit DACs.

Need Volume Control? No Problem.
If you’re using headphones, just add a Magni Uber for adjustable volume via its preamp outputs. No headphones? Just add a SYS Passive Preamp for analog volume control.

I have the Audioengine A5+ and I'm trying to squeeze better sound out of them. Is the Modi 2 a good fit? Would the magni 2 or Vali 2 add both headphone capability and offer an additional volume control for the audioengine A5+ speakers?

Also from the descriptions of Modi2, uber, and multibit descriptions make no sense at all. Do they actually improve sound quality? or do they just offer more outputs for different things?