I recently purchased the FiiO E18 USB DAC/Amp and this is my first experience using a portable DAC/Amp. I have to be honest and say that I am suprised by the performance of this device. I first used the FiiO E18 on my Samsung Galaxy Tab S2 8.0" (SM-T713) running Android 6.01 using Poweramp Player (alpha build 703). The sound was amazing and even better when I switched the Poweramp output from the OpenSL ES to the experimental Hi-Res Output 24bit/96kHz. The sound came alive with such clarity and range that I had not heard except from my $6K Stereo System I had in the 1980's. (Yes, I am that old and still love great sounding music.) All styles of my music was clear, precise and full. Then I tried it on my old HTC One M7 running Android 4.4.3 that was collecting dust just to see if it would work. After updating the Poweramp Player I had no difficulty in getting it to run. The sound was almost as great as on the Samsumg Galaxy Tab S2 tablet but the Poweramp update did not have the Hi-Res output selection. Only the OpenSL ES output possible because of the older Android version I was using on the HTC One (M7). I have been so happily surprised by not only the sound but also the company that I am planning on purchasing new FiiO X5 (Gen.3) Hi-Res Player when availible. From everything I have read on FiiO and their products, including the new X5 Lossless Hi-Res Player, I believe I will be doing business with them for many years to come. ADDENDUM: I waNtED to add that I purchased an additional 12" USB OTG cable to connect the Samsung Galaxy Tab S2 tablet to the FiiO E18 USB DAC/Amp for simplification as the 2 USB OTG cables the came with the device works great for a smartphone but not for a tablet!!