I had been quite pleased with the Creek unit, which has received excellent reviews here and elsewhere, but the Micro Amp unit is just clearly better.

It seems to go through a pair of 9 volt rechargeable batteries in about 4 hours, but that is why I bought rechargeables. It also comes with an AC converter.

I recently purchased this amp to use with an ipod when traveling. I already owned a Creek OBH-11, but that unit is not portable. The model I bought is the Micro Amp with the desktop module. I tested it out with the ipod, to which I had downloaded a variety of CDs using Apple lossless, and a Sennheiser HD 600. I was extremely impressed with the sound reproduction. For amusement, I compared it to the Creek using the same equipment. The Micro Amp was better in every respect. With the Micro Amp I could hear individual instruments much more clearly and spatially separated. It was as if some were in front of me--to the right, to the left, and directly in front--and some were to the sides, both right and left. Quite an experience.

An additional advantage of the Micro Amp is that there is a continuous volume adjustment. With the Creek, I have frequently had to choose between a little to soft and a little too loud.