I’ve now been using the Sabaj DA2 (same as iDEA) for several weeks now.
I have to say it does a good job for the £50 or so it cost. It does seem to noticeably lift the sound to a level above what the headphone jacks on typical mobile devices, and removes a good bit of the veil and provides better dynamics and a little more detail. It’s good enough in conjunction with my MT220s to use instead of my main desktop rig which is that better again, but it’s quite close really in terms of enjoyment.
A few things I’ve noticed which has probably been brought up already. It works fine on the iPad but it has a weird habit of pausing the music randomly, which unfortunately I have been unable to resolve and makes the iPad for me unusable as a primary listening device. This is particularly annoying after paying £30 for an adapter to make it fit.
On my s7 edge it again works fine, but you do have to play the music first before plugging the DA2 or you simply get buzzing. Sometimes it takes more than one attempt. However, once it locks on, it’s perfect.
It works flawlessly on my MacBook Air, so far as I can tell (I say that because I’ve only had the Mac a few days and it’s already faulty so I’m having to send it back). Just select the sound device from the volume menu and off you go.