Smallest most effective amp?

For under $80, probably the Fiio E11. 

Fiio E11  $60

Fiio E7  $75

Fiio E07K Andes  $89

+1 E11

I was going to say the Otamatsu portable amp but that's a little stretch at $130 but pairs extremely well with the UE's and blows all over the Fiio range. 

For around $60 you can get yourself the E11 which should be fine till you get the urge or a bigger budget to upgrade to a better sounding amp.

The C&C BH amp is just over .5 inch (13mm) thick and goes for about $99 on eBay. You can read about it on the Head-Fi thread below.Wish I'd known about it before I bought my FiiO E11. The E11 is not terrible but the BH sounds significantly better for about $40 more.

Here's the thread link...

http://www.head-fi.org/t/644363/c-c-bh-portable-headphone-amp-80-hours-from-a-single-charge-buyer-review

The E11 is pretty darn thin. It fits in the coin pocket of my jeans. The E7 and E07K have DACs in them, but don't have nearly as good of an amp in them. I would definetly go with the E11. The E6 is smaller, but a vastly inferior amp (pretty much the same as the E7/E07K)

I don't own one, but I've heard good things about theDigiZoid ZO 2. It's only $20 above your range and I hear it's awesome as far as providing bass level frequencies but I still can't figure out if there is a built-in DAC or not. Not to mention it's quite small (no bigger than any of the Fiio's I believe except for the e5 and e6) and can power headphones up to 250 or so ohms.

Quote:

Originally Posted by J Bones 

I don't own one, but I've heard good things about theDigiZoid ZO 2. It's only $20 above your range and I hear it's awesome as far as providing bass level frequencies but I still can't figure out if there is a built-in DAC or not. Not to mention it's quite small (no bigger than any of the Fiio's I believe except for the e5 and e6) and can power headphones up to 250 or so ohms.

Also heard good things about the ZO2. It's advertised as a "Personal Subwoofer" so it is obviously targeted towards providing some awesome bass. Never having heard it, I can't attest to its performance. Appears to only have 3.5mm input, so no DAC function. That's actually a good thing, as a DAC won't function with an iPod, so no use paying for a DAC chip that you will never use.