Can I stream Spotify, Pandora, etc. from my Android phone via Bluetooth to this HIFi WALKER HX to enjoy the sound quality?
Yes, the H2 supports high quality Bluetooth streaming via Spotify, Pandora, etc.
When would you adjust the gain setting rather than volume? Thanks!
I have my Gain set on High and use the volume to control the audio output from zero to max. High setting gives you a higher out-put should you need it. I think the Gain setting is to adjust for different headphones used with this player. Headphone impedance can range from 8 ohms to 64 ohms. The 8 ohms would be louder at the same gain setting as 64 ohms. I like the flexibility of the controls and input/output the HiFi Walker has.
Is it possible to create a playlist on the go w/o a computer?
Yes, but you can only add songs to [My favorites]. You cannot customize the playlist name without a computer.
Can I just drag my music folder over on the SD card 1600 songs in 1 folder?
You can just drag your music into HX's folder. And yes, the player recognizes single folders with up to 1600 music files.
Does the player have a bookmark?
Yes! The player does have a bookmark. Navigate the menu to [Music Setting] – [Memory Play] – [Point] to activate bookmark. Sorry for the previous info.
How can the battery be replaced?
The unit is sealed making battery replacement not possible.