I've just thought that if the Ipod nano can load Spectrum games I could see it's output power and compare it with the one I'll have with my amplifier. I'm not sure of the one of the player I've bought, but in the amplifier as I've said says it's of 150mW
(it seems at 16 Ohm reference).
Well, this is about the Ipod nano:
"Output Power (7.26)
Another major factor for media players is how much power they output. The more power they output, the better the job they can do at driving bigger pairs of headphones. A poor media player might only output 10 or 20 milliwatts of power, which means that it would not have the juice to drive a better set of headphones than the one they come with, limiting your options to add bigger and better headphones to replace the ones they come with. We measured the output power of the iPod Nano at 29.1 milliwatts
, which is decent and enough to drive most headphones; this is enough for most in-ear and earbud style headphones. However, it will begin to choke if you try and use a very large or a particularly high impedence set of headphones; the sound will be low in volume, and it may sound overly distorted and grungy. So, the iPod Nano is fine for most earbud and in-ear type headphones, but it will have problems if you prefer a set of bigger, over hear headphones or want to use a set of professional cans; many of these will have a higher impedence and may have some issues. "
And this is about the Ipod Touch:
"Output Power (7.87)
The ability of an MP3 player like the touch to drive a bigger set of headphones than the included ones is determined by the output power; how much energy can the media player output? The more output power it has, the better job it will do of driving a bigger, higher impedance set of headphones. The iPod Touch was not lacking here; we measured the output power driving a 10 ohm reference load at 30.6 milliwatts
, which would be enough to drive all but the biggest, baddest headphones out there. We confirmed this by trying the Touch with a pair of Koss K501 studio headphones, and the Touch was capable of producing a good level of volume in these high impedance headphones. "
So it seems I'll have output power to wake up the neighborhood...
Anyway I've got the idea that if the player has an speaker included, it has to have enough output power (perhaps I'm wrong).
EDIT: It seems the amplifier will be necessary, as long as the output power in a chinese player (not mine, but other) that I've seen is of 11mW, and in the Dingoo is 15mw only.