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

This is a compact amp that does exactly what is says.To test it I took out my notoriously hard to drive AKG Q701 as well as much easier V-Modas, I used it with an old linux laptop and also an LG V20 (good DAC for a phone) and listened to several musical genres.The things I liked:Good connectors - solid and precise.Good and accurate volume control and good knob movement.Good aluminum casing.Good battery life.Nice cables out of the box.Nice design, no confusing brands, clear writing saying it is an amp.The things I didn't like:No battery indication. I wish it had 4 LEDs or 7 seg display indicating battery status like in power banks.Sound quality is really alright! In the laptop it certainly amplified a lot of the imperfections from the source. In the phone everything sounded better than the laptop by far, but then I felt some shortcomings of the amp, I got oomph on the highs and the bass (very challenging bass on the specific open backs I used - had to use the H gain switch!) Human voice stayed very clear and detailed. Busy musical scenes were graceful and clean close to what I would get with more expensive amps. I found I got the best results with the phone at mid volume and amp at mid volume. I found myself listening on and on!This amp is perfect for any situation where the gain out of any device is just too low and you need a quick fix! Also if you have high resistance headphones and looking for an inexpensive way to get MUCH more.Very pleased.