Hello, thanks for your advice. yes i've ordered the E12 DIY for now and still in process of ordering LME49990 from other seller. Just to make sure we only need 1 LME49990 op amp and didn't need to solder for this LME49990 rite? (i mean it's swapable like the stock op-amp?) I'll love to hear your guidance as your experience is one of the reason i choose this amp for now :)
Oh, and about the golden E12DIY i've asked my local agent, yes he does have it but i dunno about overseas fee. Here's the link http://www.dontblameyourears.com/277-fiio-12-diy-headphone-amplifier-silver.html, you can contact him via messenger/ym or maybe email them for overseas delivery., The price is 2.450.000 IDR which is equivalent to a little over 200 $
Since it only available in single channel SOIC, you'll definitely need two LME49990 and will have to solder them onto the adapter.