Originally Posted by Vortaku
is a cmoy really the best place to start? it seems like a cmoy isnt going to do much for sound. Is there another small amp that has a longer life expectancy for someone just breaking into this? i am looking at buying a fiio e17 but would prefer to build a portable amp if there is something that is close to comparible that i could build myself. I have shure 840s, i will be replacing the earpads witht he shure 940 pads. any suggestions?
ps: also any suggestions on which soldering iron to get?
If you're into objectivity, a CMoy probably measures as well as an O2 in many respects. It's not to be trivialized, necessarily, especially if you use 2x9V. Even with just one 9V, it does respectably with many headphones. It's only with lower impedance, high-current headphones that a CMoy really falls short and needs a buffer. There are other issues, too, to be sure - but not enough to deter your efforts at a first headphone amplifier. It will always remain my first recommendation as a DIY build for headphone audio.
As for a soldering iron, you might try the search tool or just look at this thread that's only a few spaces away from your post: