Firestone Fireye Mini Portable Headphone Amp
Firestone Fireye Mini Portable Headphone Amp
bookmark_border
Where's the price?
To negotiate the best possible price for our customers, we agree to hide prices prior to logging in.
20 Sold

search
dag.odenhall
262
Nov 21, 2013
bookmark_border
There are no indicators for which phone jack is input and which is output. Does it matter? I don't want to short anything on the first use. :-)
Nov 21, 2013
cbbrowne
113
Nov 21, 2013
bookmark_border
Look carefully on the side where the battery is (mine's translucent enough to read part numbers); there's an icon of earphones beside one jack, and an icon that apparently indicates input beside the other. Agreed, it's not terribly visible! :-)
You can also figure out which is which by plugging the earphones into one or the other; when you get the earphone jack, a blue LED turns on, indicating that the amp has turned on.
I'm liking it; prefer a lot to FiiO that I got a couple years ago.
Nov 21, 2013
dag.odenhall
262
Nov 21, 2013
bookmark_border
Ah, totally missed that. Thanks!
I'm so tempted to connect the included male-to-male wire to both jacks; would be useful when transporting it. Would that create an internal acoustic feedback loop and damage the device, I wonder?
Nov 21, 2013
Ash
405
Oct 29, 2013
bookmark_border
Hey guys,
Quick update: These shipped out from Taiwan yesterday. Hopefully we will be getting these sometime next week at our warehouse, but can't make any promises. Just know that they're coming soon! :)
Oct 29, 2013
Thatonegurlgaifeman
11
Oct 21, 2013
bookmark_border
Will this work okay with a low impedance IEM like the Sony xba3 and an android phone?
Oct 21, 2013
dorkvader
196
Oct 15, 2013
bookmark_border
looking at the PCB, there aren't enough components to implement much more than the standard implementation with battery charging,
I'm looking at TI's datasheet for the DRV601 opamp this uses and we can determine a few things. 1. THD+N is lowest at about 500mV to 1V depending on the battery charge 2. the corner freq of the opamp appears to be roughly 70 Hz (rolloff starts at about 100) 3. Acceptable gain values for the opamp are 1-10 4. The minimum load impedance is 100 ohms, so they might have something to increase the rload
Then again, for anything less than 100 ohms, amplification is completely unnecessary. 5. relatively low psrr of 88 db is ok since it's battery powered. 6. no word on the current output into load. I don't think this will work with low-sensitivity headphones at all.
Oct 15, 2013
Evilhippie
35
Oct 14, 2013
bookmark_border
Does this work on android devices? Might be interesting if it does... Edit: Never mind, its not a USB DAC, so I guess no volume control, similar to a fiio e3?
Oct 14, 2013
ShearMe
39
Oct 14, 2013
bookmark_border
I'm more worried about volume control - is there any?
Oct 14, 2013
RochRx7
85
Oct 14, 2013
bookmark_border
Power the HD600's? To reference level.. or just enough to get noise? Is this real life!?!?!
Oct 14, 2013
dorkvader
196
Oct 15, 2013
bookmark_border
The specifications are quoted from firestone's website. Sadly even the manufacturer itself deosn't have any real information (gain, current output for various impedances, etc) Nevertheless, if it can output 2V RMS, it will be able to drive even an HD600 into "too loud" territory. (The HD600 has a sensitivity of 102 dB/V, according to headroom.)
As far as "reference level", that phrase is basically meaningless, but it should be able to at least "sound good" (that is, operate not too far out of spec, as far as distortion goes), as higher impedance headphones need little current, so the amp most likely wont be overtaxing itself. What's more, you'll have to have a higher volume (and more voltage) so the dynamic range will be much closer to the 110 db at the 2VRMS level.
That said, I probably wouldn't use a pair of HD600's portably.
if the "real" specifications were published anywhere, I'd consider buying this, but as it is, i'd rather just keep using my ancient cowon D2.
Oct 15, 2013