Some more specs about the amp (from
http://www.electric-avenues.com):
Most portable devices have an output power under 20 mW (milliwatts). This often isn't enough to enable a decent pair of headphones to reach their full potential.
The PA2V2 has an output power of up to 200 mW RMS and makes the music louder by a factor of 610%. The amp can power speakers too, not only headphones. For a small device it can output a lot of power. The frequency response goes from 5Hz to well beyond 40KHz. Critical components are joined with thick, point to point traces for maximum conductivity. The signal to noise ratio (SNR) is 100 dB. Actually, with the volume turned on maximum, and no music playing, there is no static sound or hiss, which is something desirable. Building an extremely quiet, low distortion amplifier was a high priority. An improved power supply filter circuit almost eliminates the 50/60 Hz humming sounds some owners reported when listening with the AC adapter plugged in.
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Like I wrote before, tests I did made it clear that when I open up the gain completely at the PA2V2 and keep the gain-level at the Iriver H120 at 0dB I get about the same peaklevels as without the PA2V2 and the gainlevel of the Iriver at +20dB.
Next weekend I hope to do a live recording and maybe I can test the PA2V2 overthere.
If I got any results I will post it overhere.