Home > DIY HiFi > FiiO D3V2 Mods

FiiO D3V2 Mods

December 1, 2012 Leave a comment Go to comments

(Update 12/2/12)

I performed a frequency response plot for my modded D3V2. The red response line is a Behringer USB DAC I used to obtain a baseline response curve. As you can see it is more or less flat from 20-20KHz. The blue response line is the D3. Yes it does roll off a little, about 3dB, starting at 10KHz. I doubt that is audible. Certainly not many loudspeakers are any better. Not bad for 20 bucks or so.



Gauging form the number of comments on the “Inside FiiO D3” post, it seems there is a lot of interest in this low cost device.

Mr Scott sent me a few photos of his modded D3V2. The FiiO D3V2 is the infamous version that many complained of having rolled-off highs. But according to Mr Scott,

My experience with the D3 V2 is that I did not have any complaints with the stock unit that I received. After the mods it has definitely improved with regards to clarity and soundstage. Even though I have 56 year old ears, I’ve been a musician for about 40 years, I design and build top end hi-fi tube amps, and have been a discerning listener for a long time.

Thus, contrary to others experiences, this device seems to operate properly. In any case, here are the photos of his modded D3

D3V2 indeed…



Changed the op amp to the AD8656, and the electrolytic to a Nichicon KA series audio cap bypass with a Wima 0.022uF.


Also replaced the zener 3.3V regulator with an ST Microelectronics LE33CZ 3.3V regulator.

If anyone else wants to do this, you must remove the zener as well as the two 75 ohm paralleled resistors that are connected to the cathode of the zener. Then you connect the ground of the LE33CZ to the pad where the anode of the zener was, the “in” of the regulator goes to where the two 75 ohm resistors were, nearest the edge of the circuit board. The “out” of the LE33CZ goes to the pad where the cathode of the zener was.


Here is a closeup of the 3.3 regulator


After listening to this with the mods, I can say that the stereo separation and “spaciousness” (for lack of a better word), has definitely improved.

BTW, Mr Scott is “Scott17” at diyaudio [link]


  1. December 11, 2013 at 07:36


    I really enjoyed your article it was a worth while read – I wondred if I could clarify a basic points as I have two left channel Sounsience QSB speakers each speaker has a 4cm Balanced Modal Radiator panel, a driver technology specifically designed for maximum quality in minimum space. I bought two pairs as they were going for £19.99 each

    Read more at SoundScience QSB > http://www.trustedreviews.com/soundscience-qsb_Portable-Audio_review#tr-review-summary

    When using them as designed the right side speakers normally control signal in via mini usb in from a computer only – this normally then outputs via RCA to the left channel from the right they work off 2.5 watts as a pair… but output is equal to 30 watts (no doubt in the right speaker which I am not using in the set up there is some onboard amplification but I can’t be sure about that as what I have read says the power and the volume control comes from the computer.

    Eliminating the source feed right side speakers allows me to prehaps direct the source in, well this is the hope without using an external amp ?

    What I want to do is use the D3 to send a RCA signal to the two left speakers now used as right and left channel speakers this way I can control the source in.

    What I need to know is what happens to the computer from a macbook pro signal that throughputs the D3 to work out if their will be enough signal to power these speakers from the computer through the D3 as they only need 2.5 watts ?

    Any advice you can give me would be great as regards the signal limitations or power output at the analogue out stage from the D3 feed from my laptop ?

    • BlgGear
      December 17, 2013 at 20:41

      The D3 does not have power to power speakers. Needs to go into an amplifier.

  2. March 16, 2014 at 02:51

    Are there any V1 improvements possible ???

    I have 2 small spare Blackgate BG-NX UF 47 capacitors normally used for ipod mods would they work in the fiio D3 V1 what changes would be nercessery to fit them ?

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