A good rule of thumb: An amplifier's output impedance should be lower than the impedance of the headphones you're using by a factor of eight or so.
Though digital audio is far from a new technology, on the consumer front, there can be quite a bit to be desired when it comes to sonic quality.
But beware of the following; GROOVE is playing beastly high. Take care of your hearing !!
Compatible with 2018 USB-C iPad Pro!
The drivers will take you into a mini program, and here it becomes obvious that Apogee is accustomed to relate to customers with a professional touch.
"Sennheiser - HDV 820 Audiophile Digital Headphone Amplifier"
... from Apogee's online store during the sale will be automatically entered to win an Apogee Groove Anniversary Edition USB DAC and headphone amp.
You link the device to a computer through a micro USB socket located on the top of the box and besides which you'll find a system to hook a strap.