I have an iRiver iMP 550 "Slim-X" CD/MP3 player that sadly has a paltry 12 mw @ 16 ohm headphone output. I tried the recently new improved "Airhead" portable amp but that was a bad experience. I got virtually no gain in volume and little more than excessive clipping with all sorts of various headphones. So that unit went back. Can any of you recommend an alternative product that would significantly increase the volume without clipping?

Hello, the iMP-550 is something I have, along with the Boostaroo! www.Boostaroo.com ? That's where I got it from... It only boosts volume by 40% and takes two AA batteries but, it allows this louder audio to be split three different ways (3 jacks). I just don't like having all those wirings (player to remote absolutely necessary, wire from small (TERRIBLE SPOT) headphone jack to my Boostaroo, wire from Boostaroo to my headphones) that come with the iMP-550 just to use it decently. I wish CD players used Bluetooth or a similar wireless periphreal (sp?) protocol...

If your handy with a soldering iron you can build your own at a fraction of the cost for what you can buy. Also, by building your own you have the option of swapping out parts to customize it a bit. Change battery sizes and amounts for different sized cases or longer run time.
Link
Link

The first link is a real good "beginner" link while the second is essentially the same amp but is a bit more technical. I'd recommend reading both of them however. To do the basic model would run ya around 20 bucks in parts if you dont go with high end resistors and caps. Granted, you could step up to high end components and spend 20 bucks per component, but really no need on a headphone amp.

Cheers,
Shockwave

My recommendation.

I've got the XIN Super Mini, and I love it. The Super Micro is better in some ways, but has a shorter battery life. Very high-quality components in both models. I've never had a problem with the sound quality with mine, which has an AD823 op/amp. You can get the even better AD8620 op/amp in the Super Micro.

I've used a Headsave Mint and JMTaudio Serpac Meta, and had good results with both.

Although likely less important in a portable setting, there's an argument for synergy between an amp and phones. I've used the above with Grado SR60, SR225, Sony V6, and Etymotic ER4S for the record.

The Little Dot Micro+ is a good value. I can't tell the difference between it and my Xin Supermacro III or Porta Corda.