http://thegame21x.files.wordpress.co...pg?w=450&h=337 Headphone amps are pretty much standard equipment in the setups of audiophiles everywhere. Over the past few weeks, I've been doing a lot of research on headphone amps and come across a number of different amps in all shapes and sizes but the one type of amp that piqued my interest was the "CMoy" amp. This type of amp, designed years ago by Chu Moy is an unconventional but powerful amp design that can be made by anyone with the right parts and a soldering iron. Well, I don't consider myself one of the handiest of guys with a soldering iron at the moment so, instead of taking a chance and trying to build one myself, I decided to buy one that had been pre-made from a company called JDS Labs. After a few hours of listening, I'm impressed. http://thegame21x.files.wordpress.co...bb-8.jpg?w=450 My previous experience with headphone amps is definitely limited, as the only ones I've ever owned are the Fiio E5 and E1 portable amps. I decided to get these after buying my RE0s because of their relatively high impedance and thinking that they would need a bit more power than my iPod Touch could provide on its own. The Fiio amps are good for what they are but they really don’t pack a big enough punch to add that special something to most of my headphones. So, I decided to pick up a more powerful amp that I could use to power the headphones I currently have and those I add to my collection in the future. A CMoy amp was a natural choice because they are plenty powerful, offer great sound quality and are inexpensive. As long as you get a good one that is. And let me tell you, the JDS Labs CMoy BB is definitely good. It would be good enough if it merely amplified the signal going to my headphones enough to unleash their full sonic potential but the one thing that makes this CMoy stand out from the average homemade CMoy amp you can find on eBay for varying amounts is in its very name. I am of course talking about the bass boost feature. http://thegame21x.files.wordpress.co...pg?w=450&h=337 As you can see in the picture above, there's an internal toggle switch that boosts the low end considerably. The Fiio E5 had a similar feature but it was nowhere near as impactful or enjoyable as the boost generated by this amp. Toggled off, the frequency response is quite flat and neutral; coloring the sound no more than any other amp I’ve used but with the bass boost feature on, the bass comes alive. This feature turns my normally neutral RE0s into bass monsters. The RE0s already had good bass detail so the result of this amplification merely allowed that aspect of the RE0’s performance stand out. As much as I enjoyed my RE0s before, I enjoy them even more now with the increased bass response which benefits my tastes in music. Honestly, the bass boost feature is almost worth the price of admission by itself. For people who desire more transparent sound, as I said before, without the bass boost feature toggled on, the frequency response is flat which is good if you have headphones that already have enough bass for your tastes. Seeing as I love my bass and the RE0s are relatively light in that regard (but not too much so that it sounds imbalanced), this was a natural choice for me. The geek factor of owning a headphone amp that’s enclosed in an Altoids tin is a nice bonus too. http://thegame21x.files.wordpress.co...pg?w=450&h=337 Overall, despite my limited experience with headphone amplifiers, I can tell that this one is pretty good. I don't expect that this can compete with the likes of more expensive amplifiers that can cost hundreds, even thousands of dollars (!) but for the price (about $70 including shipping); the performance is excellent so far and I'm sure that this competes well above its price range. I’ve heard that many headphone amplifiers (as well as this one) need a few dozen hours of burn in before they sound their best but even now, I’m definitely impressed. This is an easy recommendation for people on a budget who need a little more juice to power their high impedance headphones and/or would like to add a bit more “oomph” to the low end.