I been looking at the
Hidizs S9PRO, Are they any good? I got a dragonfly but i'm uncertain to keep it, I have a old android phone and the audio cuts out when I open a app up. What are better performer then the dragonfly?
The killer feature of the dragonfly dongles is their extraordinarily low power consumption, both at idle and when working. Of course this doesn't make for sexy marketing so they make up spurious claims about sound quality and technical prowess and promote them that way instead. I think if you are used to a dragonfly dongle paired with a smartphone then you will get a truly horrible surprise when you try many competing products and notice the impact on your battery life. This is really worth looking into! If manufacturers decline to specify power consumption then avoid. And if it's in 100s of mA, as is often the case, then, again, avoid. A year ago I bought a Musiland MU1 dongle on the strength of Amir's review, its ~1ohm output impedance, and also on its very modest power consumption. I used it trouble free for the year, it's very good. Recently I upgraded to a Musiland MU2 Mk III which has tiny power consumption, in line volume control, in line voltage control (up to 1.7v so does a reasonable job of powering everything from the most sensitive IEM up to full size headphones) and supports DSD. It's really worth a look.
edit: I corrected "100s of mW" to "100s of Ma".