Fosi Audio GR40
The Fosi Audio GR40 is a tube DAC amp that brings a lot to the table, specially considering the price. Right from the first touch, you can feel this thing is built like a tank, solid, heavy and sturdy. The design is slick, simple and clean, giving it a very nice desktop presence.
The analog volume knob and the two tone control knobs (bass and treble) feels good in hand, but honestly, they don’t feel super premium. However, for this price, it’s totally acceptable. The volume knob has a push-to-turn-on button, which feels a bit cheap to me. I personally would prefer if it just turn on by rotating the knob directly, would feel smoother and more natural.
Disclaimer
I got the Fosi Audio GR40 sent over by Fosi Audio for review, just to be clear. Everything I’m saying here is just my own thoughts, nobody told me what to say or anything like that. They didn’t pay me either, just sent the unit, that’s all.
Quick note tho: I’m the type who’s all about that warm, analog kinda sound. You know, where the music feels thick and cozy, bass and mids got a little extra oomph to ’em. I love when stuff sounds full and kinda soft around the edges, like vinyl. Natural, chilled out, not all sharp and clinical. That’s the kinda sound that really pulls me in, makes me just sit back and lose track of time. So yeah, just keep that in mind, that’s the sorta thing I’m basing this review on.
If you’re thinking about grabbing one, you can check it out at Fosi Audio. And if you’re in Bangladesh, you could hit up GeekMart for it.
Build and Features
One of the things that really surprised me is the tube itself. It’s a good quality tube, not some cheap local Chinese one. Which is very good to see in this budget range.
You get a lot of options for connections:
- Four Inputs: Bluetooth, USB-C, Optical, and Coaxial
- Two Outputs: RCA (for speakers/amps) and 3.5mm headphone jack
Headphone Amplifier Power:
- 300mW @ 16 Ohm
- 250mW @ 32 Ohm
- 50mW @ 250 Ohm
- 40mW @ 300 Ohm
Inside, it’s using the ESS9028Q2M DAC chip, which is known for giving clean, detailed sound without being sharp or harsh.
Sound Quality
Overall Sound
The GR40 sounds warm, smooth, and musical, just what you expect from a good tube amp. But here’s the surprising part: even though it has that warm tube character, it doesn’t loss treble details. You still hear plenty of high-frequency sparkle and air, which keeps the music alive and engaging.
Listening to Gary Moore – “Still Got The Blues”, the guitar strings had that emotional weight, with beautiful warmth but still keeping the string shimmer clear and natural.
Bass
The sub-bass have a nice rumble and texture, specially in tracks like Led Zeppelin – “Whole Lotta Love” where you can feel that deep undercurrent of bass moving the track forward. The mid-bass punch is decent, not the hardest hitting in my ears, but still very enjoyable.
If you want more bass punch and rumble, the Bass tone control lets you dial it up easily to your liking without making the sound muddy.
Vocals
- Male Vocals sounds meaty, thick, and mature. Listening to Freddie Mercury in “Bohemian Rhapsody”, you can really feel the power and weight of his voice. It’s bold and soulful, just how it should be.
- Female Vocals have a nice energy and sparkle. Playing Martika – “Toy Soldiers”, her voice floats beautifully with a touch of sweetness, never sounding dull.
And if you want a bit more sparkle in female vocals or acoustic instruments, you can easily tweak it using the Treble tone control.
Treble
Honestly, the treble performance surprised me for a tube amp at this price.
There’s plenty of energy and air, but it never get sharp or sibilant. It always stays smooth and natural, even when listening to brighter recordings. Cymbals in Queen’s “Don’t Stop Me Now” sounded crisp and lively, not harsh at all.
Soundstage and Instrument Separation
The soundstage is decent, there’s nice width and good depth for a tube DAC amp.
- Instrument separation is good.
- Placement of instruments are clear and natural.
When listening to classical tracks or jazz instrumentals, like Miles Davis’ “So What”, the GR40 gives every instrument its own little space without feeling crowded.
String instruments, piano and trumpet sound smooth, full and natural, with that warm tube touch making everything more emotional and musical.
User Experience
Setting up the GR40 is very easy.
Bluetooth works nicely and connects fast.
You can also use it as a preamp, which is a nice bonus if you want to feed it into a speaker amp later.
There are few small things to keep in mind:
- The tube needs a few minutes to warm up before it sounds it’s best.
- When you plug in the headphone jack, you might hear a little “ting” sound, it’s normal for tube amps.
- If you move the DAC amp while playing music, you might hear a little noise.
- With some sensitive IEMs, there is noticeable background noise. With normal headphones, there’s no such issue.
(So better suited for headphones rather than ultra-sensitive IEMs.)
Conclusion
The Fosi Audio GR40 is an excellent tube DAC/amp combo for the price.
It gives you:
- Solid build
- Warm, musical sound with lots of detail
- Good connectivity options
- Handy tone controls for fine tuning bass and treble
- A beautiful tube listening experience without spending a fortune
It pairs beautifully with guitar-based music, jazz, classical, and even rock tracks.
If you love natural, emotional, and slightly warm sound with a good amount of detail, the GR40 will definitely make you smile.
Recommended Tracks to enjoy on Fosi Audio GR40:
- Gary Moore – “Still Got the Blues” (for emotional guitar and warm male vocals)
- Martika – “Toy Soldiers” (for sweet and sparkling female vocals)
- Led Zeppelin – “Stairway to Heaven” (for instrumental layering and natural mids)
- Queen – “Bohemian Rhapsody” (for vocal power and soundstage)
- Miles Davis – “So What” (for jazz lovers, hear how smooth the trumpet sounds)
- Ludovico Einaudi – “Nuvole Bianche” (for beautiful piano textures)
Happy Listening
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