Review on Portable Headphone Amp With 3.5Mm Stereo Audio Out, GAIN Support & Lithium Battery - Compatible With IPhone/Cellular Phone/MP3/MP4 /Computers. by Jason Ampongan

I bought this to use with high ohm headphones and my iPad. I have noted, so far, a marginal improvement in overall volume and sound quality using it vs, connecting the phones directly to the iPad. The volume knob is fairly sensitive. It is necessary to keep the gain switch on high. I have a more expensive amp/DAC for use with my iPhone which produces noticeably superior sound quality but as an inexpensive solution for the iPad (which is not supported by the amp/DAC, it is worth the $$. I haven't had to recharge it yet after several short term uses.