Hi Mark2410,
Nice review!
I bought the X3 recently replacing the Sansa Fuze. I use a
modded Creative Aurvana Live! when I commute and a modded
Denon AH D1001 at the office with a
Fostex HP-A3 modded with an OPA627 and an
Aqvox Power Supply. Link for Markl type Headphone mod is found
here. Both headphones are stuffed so the sound is well balanced and the bass does neither stand out nor looses its pressure (no pad lift mod applied, no cable replaced). The CAL! sound more compact and livelier with an impressive bass, the Denons sound a bit brighter, more distant with a nicer sound stage and more relaxed. On the Fostex with the Denons I use the Koss Adapter from the Porta Pro, which is drier, a bit darker and the bass ends up to be a bit tighter in comparison with the supplied adapter from Denon or Creative. The Creative Adapter is a perfect match for the CAL! and corresponds in sound signature to the X3 output. The lively sound of the CAL! is a perfect match for Fiio X3, perfect tonality and enjoyable. Yet at the office, I was able to increase sound quality using the X3 as a digital source to the Fostex. I convert the digital signal from coax to optical using the Oehlbach converter which is excellent. I also use high quality coax and optical cables.
I listen to a lot of HiRes music of different genres. Classical, soul, pop, jazz, etc.. I also upsample CDs to 24/96 using Foobar2000 and Secret Rabbit Resampler Plugin (
Download Link). For the Fostex it is best to resample everything beforehand to 2496 (The internal resampler did not convince me.). For using just the X3 upsampling CDs to 88.2 kHz should be ok. I prefer 96/88.2 kHz even over 192/176.2 kHz, that might be a matter of taste. I miss the playlist function and memory/resume not always working is an issue. Also the fast forward with long tracks (classical ac3 recordings from DVB converted to flac) could be faster. But using a cue file is a good workaround.
Some purchased material has embedded pictures which are so big that this causes problems with the X3. I reduce them in size, this helps (300x300 pixels for example). Two other tricks which worked for me to increase sound quality is to set gain to high and to use an accu pack as an external power supply. The accu pack should be powerful enough to charge tablets (2A), standard power adapters from regular smart phones do not help alot.
So the X3 may also work extremely well with less costy headphone and using the X3 as a digital source to replace your computer you can get marvellous results.
Enjoy
Joachim