As a budget Audiophile. Basically one who has no budget 😁 I needed something that was affordable and could be a mix of office and portable. It was hard to have a nice system at home then come in to work to listen to earbuds. So I thought how do I do this without breaking the bank, but can also use at home and office as well. So I picked up A Fiio X5MIII(used for $150.Plus two 256SD cards) portable unit so I could use the DAC on the go. I also wanted one that would do most Hi=Res file options but wanted Native DSD Conversion and this had the AK4490. you get two for them, one for each channel . It also has the ability to pick up DLNA for streaming from a Serviio server I have running. I then picked up two K5 (75.00 used ) Amplifiers that use the X5 as the DAC. Then I added a pair ESS422H Heil headphone (on sale for $99.00 ) Swapped out the cushions with Sure 1540 Pads. This opened them up quite a bit. I had read many reviews that put them up against 800 to 1000 dollar headphones and still preferred them. I have to say the sound vs $$ has worked out better than I could have imagined. Milage may very as the Dap is getting a little on the old side and there are many newer ones out depending on your needs.