Quote:
Originally Posted by xnothingpoetic /img/forum/go_quote.gif
Can anyone confirm this?:
FiiO E3 usage warning!
If so, I will mod some caps on it, but I don't know where to put them? (just on the output?)And while I'm in there, I might as well put a power switch on it. Might seem like a waste of time for such a cheap amp, and one that might not even be worth the effort- but w/e.
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Uhm, the chip in the FiiO is a National Semiconductor LM4917. It's especially made for audio applications. So I don't buy this "China prototype" trashtalk. The reason the FiiO's cheap is because it's mass-produced and they don't have ridiculously high profit margins.
As for caps, this is from the LM4917 data sheet:
"
ELIMINATING THE OUTPUT COUPLING CAPACITOR
The LM4917 features a low noise inverting charge pump that
generates an internal negative supply voltage. This allows
the outputs of the LM4917 to be biased about GND instead
of a nominal DC voltage, like traditional headphone amplifiers.
Because there is no DC component, the large DC
blocking capacitors (typically 220μF) are not necessary. The
coupling capacitors are replaced by two, small ceramic
charge pump capacitors, saving board space and cost.
Eliminating the output coupling capacitors also improves low
frequency response. The headphone impedance and the
output capacitor form a high pass filter that not only blocks
the DC component of the output, but also attenuates low
frequencies, impacting the bass response. Because the
LM4917 does not require the output coupling capacitors, the
low frequency response of the device is not degraded by
external components.
In addition to eliminating the output coupling capacitors, the
ground referenced output nearly doubles the available dynamic
range of the LM4917 when compared to a traditional
headphone amplifier operating from the same supply voltage."
I.e., no need to worry, unless you don't trust National Semiconductor.
I've has no problems whatsoever with two pairs of ER-4S and one iM716. Maybe the poor uncle connected the FiiO to the line-out or maxed out the volume in an effort to "burn in" the headphones? Or maybe he's making a living out of building cmoys and recently saw his profits go down. Who knows?
I doubt that a proper working FiiO would damage your headphones. Considering all the people on head-fi who bought it and no other reports except this "uncle", who for all I know could well be an imbecille who just turned up the volume too loud, or used a defective unit.