

🎧 Elevate your sound game—because your ears deserve the best.
The Fosi Audio Q4 is a compact, entry-level DAC and headphone amplifier designed for professionals seeking superior audio clarity. Supporting 24-bit/192kHz high-definition sound with USB, Optical, and Coaxial inputs, it drives headphones from 16Ω to 200Ω and outputs via 3.5mm and RCA. Its metal chassis ensures durability, while adjustable bass and treble controls provide personalized sound tuning. Plug-and-play convenience and included cables make it an instant upgrade for desktop and home stereo setups.
















| ASIN | B07VDQQY95 |
| Best Sellers Rank | #9,466 in Electronics ( See Top 100 in Electronics ) #12 in Headphone Amps #39 in Audio Component Amplifiers |
| Brand Name | Fosi Audio |
| Customer Reviews | 4.4 4.4 out of 5 stars (3,251) |
| Included Components | User Guide |
| Interface | Coaxial, Optical, USB |
| Item Dimensions L x W | 3.9"L x 2.9"W |
| Item Weight | 430 Grams |
| Manufacturer | Fosi Audio |
| Material Type | Metal |
| Maximum Supply Voltage | 5 Volts (DC) |
| Minimum Supply Voltage | 5 Volts (DC) |
| Mounting Type | Tabletop Mount |
| Number of Channels | 1 |
| Number of Pins | 11 |
| Unit Count | 1.0 Count |
| Warranty Description | 24-month warranty |
W**M
I love it! The audio is fantastic! Great little piece of equipment.
I love this! Listening to music and watching movies on my PC using spatial sound is great. The quality of the sound is superb! My two slight complaints are as follows: 1) To power the unit you have to use a USB slot on your PC which seems like a waste. It might be possible to use a phone charger and plug it into the wall, I haven't tried that yet. 2) The knobs could be ever so slightly bigger. But that is it. I had no issues hooking it up, it works great and I'm very satisfied with the audio. I'm using it on a Windows 11 PC in Secure Boot with no issues. One of the main reasons why I bought it was to be able to turn the volume up or down on the fly without having to go into Windows to adjust the sound. Sometimes if you're scrolling through videos online, one might be quiet and another might be loud. This is a very useful feature. Overall, great value for the money!
N**Y
A tenative review, we'll see if it lives. Let's give it the final star.
After losing five $20-30 headphone amplifiers in a row, within days or weeks, just because we're tripling the cost here doesn't necessary mean this will do better. In the q&a section one person warned me it died within two months, another person says it's been running for two years. Why a solid state device should have any life is beyond me, my beloved 50+ year old Nakamichi RE-3 receiver is still running fine. My question was, since this does not have a 3.5 audio input, can it be fed by a PC into the coaxial input with a converter? Four people said yes, one said no. It's no. So, what use is a 3.5 to coaxial conversion plug? Never mind. Since I cannot get my Dell running Windows 10 to put any sound into this through the USB route, it's useless, to me at least, as a PC headphone driver. One of the days I suppose I should get the headphone jack fixed, it's dead for some reason. Still working on that, the last headphone amp I had died, so my PC is going through the Nakamichi for awhile, rather clumsy. I also need an amp for my new Vizio TV. It also has a 3.5 audio out, forget about that. Therefore, I hooked up the optical input, and nothing, no sound at all. I checked all the connections, seemed to be okay, but just before I ripped it out to send it back to Azon, the darn thing turned on. Is there a warm-up delay?? It will be on all the time, so hopefully it will keep running. One other slight problem, the cords are absurdly too short, the optical cable isn't even as long as my TV. No biggie of course, but if you're going to put cords in the box, at least make them long enough to be useful. So, I'll live with this for awhile, and then edit the review . . . one way or the other. Ed: One thing, normally I set the volume control at about 75% on everything, and adjust the volume to my earphones through an in-line control. When set like that, I was picking up sputtering sounds on some Youboob videos, but it was fine on video files played from a USB stick (the only two ways I use the TV). Youevil volumes are much higher than typical USB files, I knew that, and the USB files play fine. I was not picking up any problems on my PC, so I switched out everything, the in-line volume wheel controls, the earphones, both combinations, and it was definitely something in the TV audio. I turns out I had the volume set waaaay too high on the Fosi box, with the in-line control taken out, the headphones were blasting. I played around with the volume knob, and lo and behold, the sputtering sounds went away. I had to fine tune it so the in-line control had enough room with both Eviltube and USB sources, which worked out to be around 55%. If you're having problems, you might try turning it down. Note, the variable audio output on my TV does not work if you plug in something to the optical output, so unless you want to get up off the couch every 30 seconds to adjust the Fosi volume, in-line controls are a must for my setup. They're very cheap, but buy them by the handful, they wear out. They work very well with YT when you run into a commercial, you can cut the volume to zero instantly. Ed: I'll bump it a star, for two reasons. First, the original unit I bought is still alive, and in the headphone amplifier world, that seems to be a real accomplishment. And, I bought another one for my 2015 Vizio, now relegated to the bedroom, and it fired up and worked as well, on optical. So now I have two of them, and I'll see how long they last. Maybe someday down the road this will get the final star. Also wik: Two months now, one is on 24/7, the other with the second TV off and on. No problems. That should be long enough for any glitches to show up. Update: Over two years now, it's on all the time, and it still works.
A**M
Great value for money
My unit had an audible hissing sound (white noise) that was more pronounced on the left channel than on the right. The hiss was always there when the unit is connected, regardless of chosen input, or if it is usb powered from the PC or directly from a power socket. After contacting Fosi support I was assured these units do have white noise and that it may be more pronounced in certain headphones. I later changed from my low impedance headphones (32 Ohm HyperX Alpha's) to a medium impedance headphone (150 Ohm Sennheiser 58x Jubilee's), and on the higher impedance phones the hissing is barely noticable - so much better performance there. Pros: 1. Good sound quality, clear and loud, especially for the price. 2. Much smaller and lighter then I expected it to be. I can take this in my backpack with my laptop to have good quality sound on-the-go. 3. Physical bass and treble eq that works very well. 4. High quality materials, especially the knobs (!) - bass and treble knobs have tactile "clicking" when turned, the volume knob has a smooth turn operation. All knobs are from metal, heavy, and feel very high quality. I greatly appreciate this. 5. Lots of connectivity options - IN usb / opt / coa, OUT front 3.5mm headphone jack or back RCA. 6. True plug&play - Easiest setup I had. Cons: 1. White noise. Especially noticeable in low impedance headphones. 2. Left and right channels differ slightly (white noise at very different levels between them), so it may not be very balanced. 3. Cannot compete with DAC/AMPs above the 100$ range in sound quality (is that even a con...?)
V**.
Bonjour ! J'ai fait l'acquistion de ce DAC Ampli car la carte son intégré de mon pc ne me permettait pas de profiter correctement de mon nouveau casque, le DT 770 Pro. J'ai commencé mes recherches en ayant aucune connaissance dans le milieu de l'audio, pour être honnête, je ne suis pas plus avancé à l'heure qu'il est mais, mon budget et mes critères m'ont amené à ce produit. Beaucoup d'avis internationaux, beaucoup d'avis assez incomplet, c'est pour cela que je vais essayer de faire de mon mieux pour vous décrire le produit. La première chose à savoir est que l'alimentation du DAC se fait via un cable micro usb, cela m'a déstabilisé au début, le câble USB-MIDI ne servant qu'à faire le lien entre le DAC et l'appareil utilisé (ici mon ordinateur). L'installation sur mon PC s'est fait automatiquement : une fois branché, le driver s'est installé automatiquement et mon pc l'a reconnu. Niveau connectique du casque, c'est une entrée Jack 3.5mm. Il y a 3 modes réglable via un petit "levier" : USB, Optique et Coaxial. Ne connaissant et n'uitilisant pas les deux derniers, je vous donne uniquement mon avis sur l'utilisation USB. Le produit en lui-même a selon moi un aspect assez qualitatif, finition en métal, les différents boutons sont solides et agréables à utiliser. NIVEAU SON maintenant, c'est là où mon manque d'expertise va entrer en jeu malheureusement, je ne pourrais pas vous donner d'aspects vraiment technique sur le rendu du son etc, je vais donc juste vous faire un comparatif entre l'utilisation de mon casque avant de faire l'acquisition du produit et une fois le produit acquis. Mon casque a une impédance de 80 Ohms, mais la carte son intégré à ma carte mère (Asus TUF B450M Plus Gaming), n'était clairement pas suffisante pour pousser le casque correctement : le son était très faible, il y avait des petites interférences, assez rares mais assez embêtantes avec un casque de cette qualité, le son saturait rapidement malgré un niveau de son en dB assez faible... et le son paraissait très étouffé. Une fois le DAC Ampli installé, sans même toucher aux boutons permettant de régler les basses et les aigus, le rendu audio s'est métamorphosé : - Son beaucoup plus clair, plus net; - Volume très puissant, réglable facilement via la "molette" de volume qui par ailleurs est très agréable à utiliser; - Le correcteur de tonalité (ajustement des graves et aigus) joue vraiment beaucoup dans la plus value de ce produit selon moi : il offre un très bon rendu, vous permet d'ajuster vos écoutes selon vos préférences et le type de musiques écouté; - J'ai enfin pu découvrir les basses de mon casque qui ont un rendu vraiment prenant. Conclusion : Je ne suis pas audiophile pour un sous, mais j'adore écouter de la musique, et ce DAC Ampli combiné à mon casque m'ont fait re découvrir des musiques que j'écoute depuis des années. C'est la première fois de ma vie que j'ai l'occasion d'écouter de la musique avec une qualité pareil, ce sont les petits détails qui changent toute l'expérience. Je ne peux que recommander ce produit au vu de son prix, sa qualité et ses fonctionnalités. Le seul "inconvénient" (qui n'en est pas un pour moi) du produit peut être l'alimentation, qui se fait par Micro USB. J'espère avoir pu vous aider via cet avis, ceux qui sont dans ma situation et qui cherchent un DAC Ampli pour driver un casque sur PC notamment, foncez !
J**N
Prima voor de prijs. Mijn koptelefoon klinkt niet best als ik deze direct aansluit op mijn laptop. Uiteindelijk gekozen voor dit apparaatje. Wat een verbetering! Ook kan ik nu mijn favoriete nummer op een hoger volume afspelen.
M**S
Lo use para conectar la tv a un estéreo sony genezi fst-2000, la tv al fosi audio q4 lo conecte a través del cable óptico y luego del dac fosi q4 al estéreo sony genezi vía rca. El audio mejor notablemente y lo mejor fue que se se pudo ecualizar los agudos que es el motivo principal por el que adquirí este equipo ya que el sony fst-2000 daba un sonido de audio con graves muy fuertes, con este equipo solucione mi problema de los agudos y se escucha muy bien. Ya puedo ecualizar la música a mi gusto graves, agudos y volumen. Recomiendo este equipo si lo buscas para un propósito similar, su diseño es pequeño cabe en la palma de la mano es bueno porque no es voluminoso y cabe en cualquier lugar para instalarse, los materiales son robustos y de calidad. Como fuente de energía utilice la entrada usb de 500mA 5v de mi tv y levanto sin problema al equipo dac fosi q4.
J**Y
Al principio solo me funcionaba con el ordenador, la escucha mejora mucho, no solo por el volumen (tengo sordera) sino porque puedes poner a tu gusto los graves y agudos. Conseguí cables para el teléfono y la tablet, pero no escuchaba nada. Me puse en contacto con el fabricante y me respondió enseguida. Su recomendación fue: que comprara un cable OTG y que activase esta función en estos dispositivos (hay una aplicación para comprobar si la tienen) Y Bingo! En el móvil ataba desactivada y en la tablet con la actualización 16 de Apple se activa sola al conectar el dispositivo. Añado foto del cable, tiene que ser OTG. Espero que sirva de ayuda. 👋
A**R
Piccolo e discreto, ma capace di far rendere al massimo ogni tipo di cuffia. Eccelle abbinato alla Audiotechinca M50X. Apprezzatissimi i controlli di tono, perfettamente tarati.