Rounding off our list of the best headphone amps is the LOXJIE P20. This headphone amp makes use of military grade vacuum tubes which give it a warmer sound overall. However, I don’t recommend using the tone controls to their extremes. I noticed that maximum bass volume will introduce mild distortion. Moving around to the front, again from left to right, we find a 3.5mm TRS headphone output, a 3.5mm TRS microphone input, a bass knob, a treble knob and a volume knob that is also a push button. Above the 3.5mm input/output, we have a small row of (blue) LEDs that show which input is selected.

Therefore, when Fosi reached out recently and asked if I would be interested in trying out and possibly reviewing any of their products, I said that I would be interested in giving the K5 Pro a whirl and seeing what they could offer in this budget priced category. CPU > Intel core i7 9700k, GPU > RTX 2070 8gb, RAM > Corsair Vengance 2x8gb 3000mhz, Motherboard > Z390 Gigabyte Aorus Pro Wifi, Storage > 1TB HDD & 2pcs of 500gb M2 SSDs, Cooling > H100I Corsair Platinum, PSU > Corsair RM750X V2 Step 5:Turn on the power switch (turn up the volume); (Note:The power switch is also the volume control knob. Unless, of course, you want to practice your español and read the Spanish version (link to blog at the end of this post).IEM - Tin HiFi T2 - MoonDrop Quarks - Tangzu Wan'er S.G - Moondrop Chu - QKZ x HBB - 7HZ Salnotes Zero edit: I know for a fact it's the poor dac chip or implementation in the Q4, I used the pre outs on it into a few amps and it was just...... well it wasn't good at all. The amp might be fine but the dac is terrible. I watch all CheapAudioMan videos. I enjoy him and I find some of his videos worth the watch, but I think that if either of the units he thrashed above were US made, then he might have something different to say. Does anyone know a solution to remove the static / hissing noise from Spotify? Any help is appreciated. Thanks Fosi Audio designs and builds innovative audio products with all your music in mind. Great sound, simple but elegant designs, high-quality materials, and truly useful features are what Fosi Audio is about. We sincerely hope you get as much enjoyment from our products as we’ve had to create them!

The rubber feet are a nice addition that I wasn’t expecting on a product at this price point, however they didn’t prevent the unit from sliding around on my glass monitor stand base, but I still greatly appreciate the scratch protection. I'm really not a fan of the Fosi Q4, the sound is a little muddy and PC onboard sounds better IMO. But it seams that you aren't using PC audio in this instance so it's probably an upgrade. My finding was the dac for the culprit as even hooked to a known quality (comparatively) amp it had the same undesirable sound signature. But to each their own. With USB, optical and coaxial S/PDIF inputs can fit with most home audio systems, and RCA output can be connected to an amplifier or powered speakers on your desktop. Built-in Hi-Fi headphone amp chip can drive most 16ohm to 200ohm headphones.

What are the most important factors that you should consider before choosing your next headphone amp? How compatible is it with your brand of headphones and device that you’ll be playing music from? What other features does it offer?

The K5 Pro is a very small device, not quite palm of the hand but not much bigger either. The enclosure is completely made from metal, in a dark grey finish, with metal knobs in a silver colour. I want to thank Fosi audio for the sample of the K5 pro, as always this is my opinion on it and I've not been paid or influenced by anything other than the music. And finally, due to the small size of the unit, some might find that it is impossible to turn the control knobs without raising the unit off it’s resting surface.This subreddit is for the budget minded audiophile that wants to grow out of soundbars, boomboxes, mini systems, portable bluetooth, lifestyle speakers, and PC peripheral branded audio solutions. Please change the power supply adaptation and retest; why? Because of the aging of the power supply, there may be an abnormal power supply resulting in white noise. We recommend using the PC-USB port/5V power adapter to power it. The Fosi K5 Pro is a good little box that offers decent performance at a very reasonable price point. The obvious question that I think people will ask is how it fairs against something like the iFi UNO, which is priced similarly and is by a brand that is probably better known in the audio realm. A handy factor to have on your headphone amp will be full control over your music. This won’t only include a volume dial or knob that you can use to adjust the volume. Headphone amps that also allow you to adjust the bass and treble independently of one another will help you to enjoy the finer aspects of your favorite music. You can easily adjust the sound to suit your needs.

Finally, before getting to sound, let’s mention the part that makes this device stand out from other devices that I have reviewed at similar price points… the mic input. Let me start off by mentioning power, as this little device claims it can output 1W at 16 Ohms, which is a lot of power for such a small device. For comparison's sake, the JDS Labs Atom claims 1W at 32 Ohms and that is an amplifier that I very rarely need to push above 50%. In the case of the K5 Pro, using the KPH40 which are 60 Ohms (the K5 claims 300mW at 64 Ohms) and I found that I could max out the amplifier without going deaf. Yes, it was loud, but it certainly wasn’t unbearable (at least for short bursts) so I am not overly confident that this device can actually produce the power it claims.I replaced the 305's with Adam T5v's after Amir's review that I like very much but i am still in two minds as to whether they have the same wow factor as the JBL's. The 305's are really special, the Adam's are still very satisfying. As to why this is actually happening only in Spotify I'm uncertain and would have to take wild guesses. I would HIGHLY recommend trying to get the budget for a Schiit Fulla or Fiio K3, that or just run onboard audio, it's far superior. Opening the box, we find the device, a USB A to USB C cable (with a removable adapter to convert it to USB-C to USB-C), a 4pin 3.5mm female to dual 3.5mm TRS cable (to use a 4 pin headset with the two separate input/outputs on the device), an optical cable and a fairly decent user manual. All in all, I think that the Fosi K5 Pro is a very interesting device for its price and, although it may not be outstanding just on the audio front, it offers a lot of options for those who are looking for a cheap, compact, all in one device for their desktop.