lack of a substantial volume increase with fireeye mini

[youngmountain]

i recently bought a firestone fireeye mini to pair up with my ipod nano 6g on the go to give a bit of volume boost and improve the sound overall, but there seems to be a lack of a perceived boost in volume. the unit has no controls of its own, just a simple box. it does however appear to be making the music more forward, symbol crashes more vibrant and the bass a little tighter and overall improves the listening experience. now i wasnt expecting an exponential increase in volume, but at the same time i wasnt expecting hardly any. i paired up the little box with my macbook pro and the volume just boomed out of the headphones (incase sonics) it was crazy loud! normally i can listen to my mbp with the volume near max comfortably but with the fireeye mini i have to turn the volume way down on the computer. why would the fireeye provide almost no volume boost with my nano, but a huge one with my mpb? have any of you experienced anything similar to this when trying to amp an ipod, or when using a portable headphone amp?
 
any input would be greatly appreciated.
 
also i did a search on the internet and the forum about the issue and turned up nothing.
 
cheers everybody. 

 

[youngmountain]

bump

 

[mikeaj]

Did you try a different cable / replugging to make sure the connection was secure?  I don't think that's it, but just checking...
 
Supposedly the gain is about 6.2 dB, output impedance about 10.7 ohms (at 1 kHz):
http://www.soundandvisionmag.com/article/mini-amp-review-fiio-e6-fireye-mini-govibe-mini-box?page=0,2
 
6.2 dB is not much—subjectively, it's somewhat agreed that about 10 dB difference is perceived as twice as loud.
 
The headphones are supposed to be about 32 ohms.  Note that the amp's output impedance is in series with the headphones impedance, so some of the signal is divided across that.  The headphones are only getting 32 / (32 + 10.7) = 75% of the amp's output, so that's 20*log10(1/0.75) = 2.5 dB lost.  I think most portable iDevices have lowish output impedance these days, below 10.7 ohms, anyhow.  So the difference could be more like 4-5 dB relative to the iPod, not that much.
 
If the MacBook Pro has a large output impedance (so the majority of the output would be lost internally when using those headphones, but almost none would be lost when connecting to an amp), much larger than the Fireye Mini, that would be the explanation.

 

[youngmountain]

i did try swapping cables (first thing i did) to no avail. I hadnt even considered the output impedance of the ipod being comparatively low. i think you are right about it being less than ten ohms. thank you for your input about my issue, i greatly appreciate it.