Fosi Audio K1 Bluetooth 5.0 DAC Headphone Amplifier Mini Stereo DAC Amp Preamplifier 24-Bit 192 KHz USB Optical Coaxial to RCA AUX Digital-to-Analog Audio Converter Adapter

I've been interested in getting an external DAC for the last couple of weeks. When I saw the Fosi K1 discounted at half the cost of a Schiit Modi 3, I had to take the plunge and try it. Ultimately, I want a DAC to connect my Chromecast audio (optical output) to my stereo receiver, speakers and subwoofer. Unfortunately, I'm still waiting on the mini-optical cable for the Chromecast audio. So for this review, I compared the Fosi K1 DAC to the on-board soundcard in my 2014 MacBook Air and 2019 MacBook Pro.What do you get with the K1? The package includes:• the K1 DAC• bluetooth antenna• a micro-USB cable for power• a USB-A-B cable to connect to a computer• an optical cable• eight adhesive bumper feet.The K1 DAC is built well and feels solid. What's obviously missing is a USB power adapter. The first thing I did was to determine the power consumption of the K1. I connected it to a RAVPower and a generic USB adapter, both at 5V and rated at maximum of 2.4A and 1.2A, respectively. To turn on the device, I simply pressed down on the volume switch for 2 seconds until the LED light in the back of unit turned on. With either adapter, the K1 drew power consistently at 0.388A. I'm confident that this DAC would work with any generic phone USB adapter.For the comparison, I listened to Spotify streamed music on a pair of Klipsch reference headphones. Both Mac laptops are running Mac OS 11.4 (Big Sur). The K1 DAC was automatically recognized by both Mac laptops without the need to install any software (plug-and-play). There was a clear power increase with the K1 DAC compared to the laptop headphone jack. At about 30% power on the K1 DAC, the music sounded extremely detailed. To achieve the same level of details without the DAC, I had to crank the volume on the laptop up to 60% to 70% power. In addition, the music on the DAC had much improved soundstage and imaging. I listened to two albums, the Eagles Hotel California and Dire Straits Brothers in Arms. With the DAC, you can tell sounds were layered one on top of the other and there was a clear sense of spatial separation between different instruments and vocals. This improvement was quite pronounced compared to the Macbook Air's on-board soundcard. Even though the Macbook Pro's soundcard is very good on its own, the K1 DAC managed to provide even greater detail in the music. Overall, I'm impressed with the performance and build of the K1 DAC, and especially at this low price.Oh, I also tried the bluetooth function. I used the volume button to change input (quick press to toggle among USB, optical, coaxial and bluetooth inputs). When I got to bluetooth, the led turned blue and started the flash. At that point, my computer detected "Fosi Audio K1" as an available bluetooth device and it connected without any problem. In brief, bluetooth connection works and it's easy to set up, but not surprisingly it doesn't sound as good as wired inputs.

This thing is amazing! My friend showed me the little micro amps that are popular right now but he recommended I get a DAC because the audio is so so after streaming from your phone... I thought DACs were digital Audio Cassettes from back in the day but after a ton of research I found Fosi and their little amps and DACs. I had no idea these little boxes can clean up your audio so well! I probably spent three hours just playing with it going back and fourth plugging my headphones into the Fosi DAC and then back into my phone... The difference was night and day, I thought my Samsung S10 had good audio too! I had my daughter even come listen, she's 8 and really thinks I'm a nerd now lol. I did use her help to test the Bluetooth range also. My regular little amp will get about 40 feet line of sight when I connect my phone but this awesome little preamp allowed her to go up stairs to her room that's the farthest in the house with three walls in between and no issues, we then tried outside and she made it to the complete other corner of our 1/3 acre lot while I was inside. I have no idea how far we can even go because we maxed out... I should of had her walk down the street. I loved it so much I took it to work and plugged it into my car stereo and it sounded amazing in there also! I am going to buy two more, one for my outdoor speakers, one for my inside setup and one for my car! I wish I wouldn't of bought a crap amp like in the picture because I have a feeling the Fosi ones are way better but I did only get mine for $20 and you get what you pay for. I honestly can't think of anything I don't like about this little beast, if you don't have a DAC on your system you need one trust me, I haven't tried any others but this one is BOSS!

I was initially not sure of the DAC chip on the device since its not the ESS or the AKM chips which other devices use. However I was happily surprised when I actually used this little guy.Source applications: Phone Netflix for movies. Spotify Premium, Youtube Music at highest setting. Line Out was tested with the Schiit Vali2 with and acted as Preamp. (Volume control and can use input of Bluetooth / USB / Optical. ) Couldn't test the Coaxial. Bluetooth: Windows laptop, iPhone SE (2016) (Headphone out or Lineout )USB: Windows with everything disabled  (Headphone out or Lineout )Optical TOSLINK: Phone -> Creative Soundblaster E5 -> K1 via cable  (Headphone out or Lineout ) Current Gear/ comparisons:AMP:  Vali2DAC/ Amp OPP HA1 (ver1) ,Create SoundBlaster E5 ProsGood Details and Separation. Was able to hear new sounds from the music which I wasn't able not hear before with my current gear. Enjoyed pairing with HE400i a lot.No hiss/noise. Clear dialogues.Was able to drive my HD650, HE400i (2016), and Talos Version 1 (TRP50-MKIII mod) with authority.Sounded great with the KOSS ksc75 as well.V shaped sound - Nice Bass Slam.Connection on the Phone Bluetooth and PC at the same time is a great convenience.I like the small package and feel.   Unable to test the Gaming chops - try the PS4 or PS5 via USBCons: Unit needs to be to plug in directly to the laptop for Sound. When plugged to the Dell Docking Station D3100, the laptop recognized the device and settings could be changed but no sound. Plugging it directly from Laptop did work.I had issues with the device at first in terms of sibilance but returned it and bought it again and the new device was great.Used the RCA out to feed my SONY AVR and the sound quality was great. I got this to make this AVR Bluetooth capable and am happy with the results.

The DAC worked well and had quite good sound for about 3 months and then broke. It only produced periodic clicking sounds alternating with a low volume distorted version of the input signal.Since the Amazon return period had expired, I emailed the company since the product was covered by a 12 month warranty. What followed was painful. On March 31 I wrote them an email. They sent me instructions on what they wanted me to do to fix it. I did everything they said to no avail. Below is what they asked me to do.May I ask if it does not have this problem at high volume?What input are you using? Does this happen in other input modes?Please try changing the sound source, cable and speakers.Please kindly try the K1 with other computer or Bluetooth device.Please switch the USB port to USB 3.0 or back USB port and try again, as some USB ports have unstable data transmission.Please connect the K1 with other device through the Optical or Coaxial input port to see if it does work correctly.Could you give me a video to show the issue and your connection clearly?I spent the time and did all this. I even had to try it out on a friend's system because I don't have an optical audio out port.At some point I didn't hear back from them at all. On April 7 I finally contacted Amazon and described the problem. They issued me a credit with no fuss. I told them that they should seriously consider allowing Fosi Audio a store on their site if they treat customers this way.What do you know? Immediately afterwards, I started getting emails one after another from Fosi. But EVEN THEN they continued to challenge that the product was defective. Below is what they asked me to do, again each in a separate email.May I know if it will produces clicking sounds when you using headphones through 3.5mm headphones out?May I know if you have replaced other power supplies during normal use before? make sure that power supply is not the problem.Please also use another Type-C power cable with 5V 1.5A power adapter.Understand that we are talking about a relatively low cost item here. $55.00. I am only spending the time to save others having to go through this aburdity.

Ottimo dacamp per rapporto qualità prezzo. Da rivedere ampiamente l'ergonomia. Per cambiare input devi premere la manopola del volume ed essendo molto leggero si sposta. I led che indicano l'input sono collocati sul retro (?). Il suono è buono ed è di costruzione semplice e solida. Peccato per le lacune descritte altrimenti sarebbe da 5 stelle.