Review on 🎧 Hifi Portable Headphone Amplifier with 3.5mm Stereo Audio Out, Switch and Dual-Output - Powered by Lithium Battery and 2-Level Boost by James Handy

This was my first headphone amp. I got it to amplify the sound of my Hifiman HE-160 headphones which obviously aren't powerful enough due to the headphone jack on my desktop PC. Also, when I'm in hotels I can't plug my headphones directly into the media box on the back of the TV because the volume is cranking, so I needed a way to control the output. The device appears to be well made with a solid metal body, a long volume knob that fits securely, has no play and is easy to grip, although having the device protruding over the edge on a table would make it more comfortable. easier to adjust the volume. The pressure on the various ports is a little small, but that may be due to my poor vision. When it comes to performance, there are both good and bad points. The status LED on the back shows if your amp is charging, fully charging or discharging (using its own battery power). It all works great, although it would be great if it didn't have a built-in battery. If that battery dies, you're just out of luck. Output power is okay, but for under $40 I can't expect much, but when the gain is switched from low to high or the bass boost is on, your usable volume is severely limited before the unit distorts, increasing the risk there is damage headphones. It is best to leave these items disabled. Since I relied on my PC's USB port for power, the amp was very loud to the point where it was unusable until I switched to a USB port on a hotel desk lamp. Then the noise disappeared completely - for a day. The problem is that after a day of use, maybe not even 3 hours, I get this high-pitched howl with a continuous cycle of bangs that occurs every 3 or 4 seconds, as if an internal capacitor might fail. I suspect this could be the reason the device gets very hot, although there is no sound other than the constant whining that developed. The frequency is extremely high, almost like a dog whistle, but low enough to be audible to my almost half-century-old ears. So I have to return this item after a very short, moderately satisfactory use. I don't know, maybe I'm just unlucky, but I don't think I'll buy another extremely cheap headphone amp again.