CX-Pro Audio 31993

DAC Chip: Conexant CX31993 (Single)
PCM 32bit – 384khz, SNR: -128dB, Power: 1 Vrms 65mW x2, USB Type-C Male, 3.5mm SE (Microphone: YES), 12mm, 5g, Aluminum Chassis with Braided Cable



  • Sparkly clean timbre, natural and realistic, mildly euphonic
  • Spacious airy note, great coherence.
  • Great Treble textures and extensions, polished crisp decays
  • Visceral Mid-Bass punch, rich textured body and crisp decays
  • Neutral Mids, not too forward nor recessed, richly texture, smooth.
  • Rich Sub-Bass with tingling and polished seismic feedback
  • Beautifully nuanced and crisp details retrieval, highly transparent
  • Realistic tonality to guitars, cello, percussions, and piano
  • Amazing speed and transients handling, amazing dexterity
  • Properly sized soundstage with natural feel to the spatial imaging
  • Great separation of layers with precise holographic projection
  • Good driving power, 65/100 volume to drive Tin HiFi P1
  • Great synergy with about anything (no lower than 94db of sensitivity & over 250Ω)
  • Very forgiving on poor quality recordings and Lo-Fi music despite being very transparent
  • Good sibilance resistances even on shouty music
  • Clean black background even on low impedance IEM (TRN-MT1)
  • Doesn’t get hot even after over 5 hours of usage.
  • Very merciful on battery drain


  • Being this cheap, there’s potential QC issue and consistencies. As with many cheap Chifi items
  • No mechanical volume adjuster
  • No Balanced Output
  • 90/100 for normal loudness on T40RP MK3
  • Compared to other dongles in the same range, driving power for demanding pairing seems lower


CX-Pro Audio CX31993. When I started this #donglemadness, this is exactly what I was hoping to discover. A true performer that’s modest and unpretentious. There’s no hype surrounding this CS unit, just sheer performance both technically and musically. It has some of the most balanced timbre projection I have listened to so far, and it is consistent across all of my IEMs and Headphones – exhibiting flexible synergy better than any other 5 stars dongle I have tested so far. It has the power, sparkly smooth Treble, deep commanding Bass, richly textured Mids, it has it all – well balanced and not overcooked. On the subject of cooking, I believe one of the reasons this CX unit exhibited stellar stability was due to great power management. It doesn’t seem to want to heat up even used for long hours. Not forgetting the merciful power draw on the host despite being a powerful unit that can drive even the notoriously stubborn Tin HiFi P1. For the asking price of no more than $13, this one is a no brainer ⭐⭐⭐⭐ performer.

18 July 2021 Update:

The arrival of my FOSTEX T40RP MK3 91db Magnetic Planar warranted for a re-test of for some of the top performers I have tested before. This include CX-Pro. The test was done using my iPhone 7 USB 2.0 (USB-C to Lightning ddHiFi adapter). All on Deezer HiFi FLAC.

First of all, the volume required to be cranked all the way to 90/100 and over for proper listening loudness. What I have observed, the CX-Pro has lost that euphonic signature to the timbre vibrancy. It is still decently engaging to not sound outright meek. However, worth to note that on many songs, I can’t shake the feeling that the overall presentation now being held back, reserved and occasionally recessed. Luckily the mids somehow managed to not degrade that it retained a semblance of neutrality to the tone and texture. Treble suffered a little as it seems the extension are not as far reaching now, it rolled off earlier. Bass remained fast and tight, still amply punchy and vibrant.

Most importantly, unlike iBasso DC04 and DF Cobalt, CX-Pro survived intact by not falling apart on timbre and dynamics coherence – despite being less euphonic now. It remained stable cranked at 90-100/100 volume. All these taken into consideration, CX-Pro retained its place in the ⭐⭐⭐⭐½ segment but will now be placed behind Shanling UA2 which fared better with the T40RP tests.

A/B Contest with Ovidius B1:
– A hair crisper and more rounded timbre on Ovidius B1
– A step more intimate Mids on Ovidius B1
– Ovidius B1 3 steps more powerful than CX-Pro (both already quite stellar in driving capability)
– Ovidius B1 still brutally unforgiving to Lo-Fi recordings, CX-Pro much more accommodating

For CX-Pro to even stand so close beside Ovidius B1 is a testament how stellar this nondescript unit is. Ovidius B1 keep on reminding me why it is still my No.1 personal best dongle.

⭐⭐⭐⭐ ($13.00)

Best Pairing: Flexible for anything less demanding under 100Ω

Back to #donglemadness

10 responses to “CX-Pro Audio 31993”

  1. Hi, got a unit on your recommendation and do you know this hobby is really fun when it lands on your desk, you plug in and….your jaw drops…can’t believe the output. Mated to an iphone 8, Senn HD 569 / MDR-Z1R (current fave). Lovely lovely. Got it as insurance for the inevitable Apple Dongle failure…..thanks again for all the reviews. You bring alot of joy to people!


  2. how much power (in vrms) does this dongle have? I just ordered the KZ PR2 with impedance/sensitivity of 15ohms/94dB. given that IEM has a planar driver, will this dongle power the IEM?


  3. You mentioned it can run P1 with 98db sens and 20ohm, now we have KZ PR2 with 94db sens but with 15ohm.

    PR2 traded sensitivity with the ohm amount but can this cx unit power the KZ PR2?


  4. Thanks for the command dc03pro,there is a difference in the bass of a different sound JCally JM6 Pro vs CX-Pro Audio 31993 These are supposed to be in-ear headphones


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