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Fosi Audio DA2120C DAC Amp review

cochon96

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Thank you, Fralle SWE, for informing me of the contact point. I have received Fosi's email. Now it works.
 

Gruesome

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Fairly simple packaging box with generous foam protection all around
heYjqDmKaVU8YWjWJyPEhzx-GKeAiIg_79azfLJm6sMNJd5yPZdMHqDy4zQgmGTPYvKRHA0NlsAPV-QCWN1KQwkV12qaisnHdFHjVRPG4EqMpCNl4UYS3EVNcKp31uW2oEUl9gW_V-OKPwnY5pEsmVS5QN0_MTa7BfP6z6aF3btkq_mvO1RXyDFXQeT2
Nf38gQe9_9BP0Pr4_mLSgcSSpjiSOp61joYYca4PuCr91dhenZIDQ8luErw4GY9T-NP5ZIRmsJWasGR-bqAk_3KQB5sq1F0AYkf6j7GjzaSYKK2gunpF6EJZdoAmTju2J2sCEHw_QGLCYhPS02I-9vtwId0y_JSX718QXY59RscnznXWKs2TwsCVGCwb
aLi-nUVcaI06X_Ovt0OQ-MUeF1y8o7TsQImZzM6M0ymCai757CtehJIdKoje-FKoBPY8Lh2QFvtWaux1Jqll6cVnXeXJGviB0gf5TvlbDTXOkgaeFNOV8debzkUsjziPsTRFTlXiZEZupNLQ4zaVBcOFZIwYBwlxqeRf4xqcOx2OZcE1hR14jBnssBIZ


The DAC/Amplifier got some weight for its size. I was surprised when I picked up the package. It has a rigid all aluminium enclosure with pretty thick walls. This unit is built like a tank, trust me. Maybe a bit overkill but hey I’m not complaining.

The volume knob is made of aluminium, with haptic rotating feels, each notch gives a 1% of volume adjustment. The volume knob is also a button for mute by pressing.

The power and input select button on the unit are both made of aluminium as well. Great positive clicky feedback.

The center of the unit is a small display, showing input, volume bar and %, sampling rate. It can be turned off using remote only.

There are functions that will not be accessible without a remote control, like EQ (useless function read below), Loudness control, tone (treble & bass) control, turn off display. Don't lose your remote, as tone control can only be adjusted using remote.

First time I plugged in the power plug on the back of the amplifier, it made a small spark. As someone who has electrical knowledge, I don’t really mind the spark because I understand there are capacitors being charged and the inrush current makes the spark. Someone who doesn’t have electrical knowledge might ask if something is wrong with the amplifier. Also, the DC power plug leaves a gap of about 3mm when fully seated.

The Bluetooth antenna is way too tall (7”). I doubt most people will be using BT 30+ ft away from the device anyway. Smaller BT antenna would be best for the look and functionality.

Now the most important part, how does it sound? I've tested it with a pair of Klipsch RP-600M bookshelf speakers, using all digital inputs. It is GOOD. I was surprised since the TI- TAS5352A chip is fairly dated (2008) compared to the more modern TI- TPA3255. I was able to use 192kHz 24bit signal on all digital inputs, except BT which is 48kHz 16bit. Aptx codec works fine on Android, not supported on iPhone.
The subwoofer output is well tuned, the sub volume changes with the main volume. I would like the crossover frequency to be indicated in the spec sheet of the device.

The EQ is useless, the preset tunes (rock, rap, jazz etc.) are so bad I would never use it at all, unless you want to torture your ears. It sounds like they boosted the bass with 30db+... The default setting is the best, and if you want to adjust Tone control feel free. I wouldn't use Loudness control either.




Now the more technical parts of the review:

By turning the volume from Zero to Max, no hissing noise came up from speakers. I also tested this using an oscilloscope. Background noise (2.7Vpp @ 4ohm, 3.3Vpp @ 8ohm) was stable across all volume ranges

50% volume, no input, noise floor:
i2tdtmNmkZZDAOY_cHukGSv9XNO1vUdM6aKppipxcUfEXUbhvQ3w16g-j4qFLC0JQM6JogBiimUuwPIGJd053NTpo1asfdUWvG2tBunbSD_xBbEW6mLLBCuPP3UyeRxRBVmnZCQo6yuE-2k4gM-zYtyo47_tFgKaXljLMl7Scfc87YIZAun8MwvBzTGX



Tested RMS power output 100hz & 1000hz, all tests are done with EQ, Tone, Loudn OFF, MAX volume on digital input:

45W per channel, 2.33A @ 19.12V 80% volume before clipping 8ohm
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81W per channel, 4.58A @ 17.73V 80% volume before clipping 4ohm
Ol2Tn3PpWSNcc16cawYmAR6IjR2kfVCFofXOu74ubLM5v7_k2T9aoG5P51tJgz6YHqoJVfL7oz--GEKHOK2y1yLbjnb6RnJiQpWiEpGzFKXyrNhPnJdbcwTV6QAZc5tlbQKioz7pQYh7dL27zAYKghE-lkq7gqgEk-lJgaHLQrFF44_3Rj_Paqf847lL


9prZ-KH4HlCFrvZ0fIJtNgajJXtfB_Kl8SkwLTLyI46fml_5WU8msAhyOtMbI7s1ldAxqj5jtsF-PdD9Gqz4j5vUMNyMBKWYUJH-v-c6EQKY4EoA-8rVl9Iy7nCgwW_dmfN_i2jhS3p38mwd8WU0Y0fotbM-VPiUZFlr9RqAp9W84Z5ZMoLgYGxGE2Y_


Clipping occurs above 80% Volume on the unit, with MAX volume from digital source, I suggest to even stay under 75% to be safe. This is with EQ Off and Loudness control Off. Zeroed Tone control. If you activate any EQ or Tone control, you will need to lower the volume to avoid clipping
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The power adapter has short circuit protection, overcurrent protection. It is capable of the rated output of 5A @ 32Vdc. Mine was measured @ 32.3Vdc
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I was curious to measure the ripple output of the power adapter under load, so I attached an 8-ohm power resistor, squeezing out 125W, 3.92A @ 31.8Vdc. 0.7Vpp ripple, meh... it is to be expected for the price.
-fLRB9vVK7QPjYppjHN4iFanu4O128-NkzjouRWgfZ5HqoAb-zwS-BSgP-TLkAShKMwpnkO09SDEto3LNttWJUibppom0mHOwU8ZI0Rmf0cPmqrOLIAsBKq8MkROv0ECiGqjopwGA-T5-Plg6WZN1aEsR3RRKMBJJSSfS-ht2pWEMtKXLXhLkcz109c7


0.3Vpp @ no load
vOgz-KpeQd6rr-ankiFJYheXfswWeESX8Hd9ZFuByVs8cqRG76b05oVgcWMNfkzGsrvdac5_tYixh2JyvKtG1UsmJEOUdUr2hSFFSvphH4eGVdhca1eeTRcU2EKDuJyYVWwU36Hh4kAvjTN1XyxClu43fLcvSdc6h-Dlz-fy5pYTpf0eDv5HNUM5d4hh

Pros:

  • Amazing build quality, it's built like a tank.
  • Good power output for its size, thanks to the power adapter
  • Good sound quality using default settings, NO EQ
  • Well-tuned sub x-over, I'd like to know the frequency
  • Great digital inputs (192/24)
  • Super high efficiency
Cons:
  • Useless EQ and Loudness control, it is abysmal
  • Give us a shorter BT antenna please! It will fit better into narrow spaces
  • Spark on connecting DC plug
In case anybody cares, the internet archive has copies of pixelwarfare's old reviews with the pictures:
e.g. for this one here, https://web.archive.org/web/2022111...eads/fosi-audio-da2120c-dac-amp-review.39264/
 

Nate R

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Apr 25, 2023
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The subwoofer output is well tuned, the sub volume changes with the main volume. I would like the crossover frequency to be indicated in the spec sheet of the device.

I bought one of these. Got out a scope and measured this myself, as I wanted to know as well.
Using a tone generator app and the Bluetooth connection, I looked at the AC Rms voltage output of a sine wave at the subwoofer output.

I got a -3db point of 125 hz, 3rd order/18 db/octave rate from there.

Interestingly, was +/- 1 db down to 10 hz, and was only down 2db at 5hz. No HP filtering, FWIW. Although I was measuring at a low level...like 55 mv at 60hz....is that something that may change drastically 30 db higher on an amplifier?
 
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grogi.giant

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Interestingly, was +/- 1 db down to 10 hz, and was only down 2db at 5hz. No HP filtering, FWIW. Although I was measuring at a low level...like 55 mv at 60hz....is that something that may change drastically 30 db higher on an amplifier?

No, it should not change much. Active subwoofer will have very high input impedance, it will not strain the low-level output from amplifier.

Were you able to measure the speaker output as well? I've seen somewhere that there is HPF applied for the speakers...
 
Last edited:

Kimbrough Xu

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No, it should not change much. Active subwoofer will have very high input impedance, it will not strain the low-level output from amplifier.

Were you able to measure the speaker output as well? I've seen somewhere that there is HPF applied for the speakers...
Why do you need a HPF for such an ampifier?
 

grogi.giant

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Why do you need a HPF for such an ampifier?

If you have a subwoofer in your system, it is generally a good idea to relief your main speakers from midbass duties (let's say <80, maybe <100Hz). That small cut in signal reduces the power they need to handle and massively reduces distortion they introduce.

I don't know where, probably one of the reviews somewhere, but I vaguely remember reading that this amplifier does apply a High Pass Filter for the main speakers, regardless if you have subwoofer connected. It would be great to verify that empirically...
 

Nate R

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Were you able to measure the speaker output as well? I've seen somewhere that there is HPF applied for the speakers...
I don't recall reading that anywhere myself, but I suppose it's possible.
I didn't measure anything else in this case. I will be doing some more measurements in the future to look at some other parameters in my subwoofer chain once I get the sub built... I'll make a note to look at the speaker level output of this amp at that time.
 

john11

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How would this amp in SQ compare against established favourites like the aiyima A07
 

john11

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Anyone have a clue how this amp compares against the aiyima a07 or a08, plus why has the da2120c not been reviewed by amir

Thanks
 

_thelaughingman

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Amir only reviews items sent in by members or the companies if they're willing to bear the objective crowd here. If you own this amp and want to send it to Amir for measurements that'd be useful and give you an answer.
 

john11

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Amir only reviews items sent in by members or the companies if they're willing to bear the objective crowd here. If you own this amp and want to send it to Amir for measurements that'd be useful and give you an answer.
Sorry i don't own this amp, do you have any idea how this fosi compares against the topping pa5 or pa3
 
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