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(Unofficial) Review of JCALLY JM20 MAX: USB-C Headphone Dongle with High Unbalanced Output Power

The rising THD+N must be due to rapidly rising THD (i.e., not due to the N part). I suspect there must be some design flaw in its power supply circuit.
E1DA (aka Ivan) mentioned this possibility on the description page of his portable DAC #9039S:
Simplified DAC tests let manufacturers "optimize" the product cost dramatically. If nobody cares about the real load testing why they'll add a heavy steady power supply in a portable DAC? Just 10uF ceramic SMD is Ok for that i.e. hundreds of times cheaper than 4500uF in 9039S. No reason for tens of PCB polishing iterations as well.
 
Not really sure, but I believe Windows volume percentage ‘curve’ is based on: 100% -0 dB; 52% -10 dB (1/10 power, ~half perceived loudness); 27% -20 dB (1/100 power); 14% -30 dB (1/1000 power)
Of course, Windows has no idea of the actual volume—that’s up to the device implementation.
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It's the typical Windows volume curve. Normally if Windows volume control is independent of the device, it will follow the curve. But if some device's volume is controlled by Windows volume slider, it will follow volume curve built in the device.
 
I realize that this YouTube video


published by Crinacle pretty much sums up most of the USB dongle DAC/headphone amp devices that ASR members are interested in these days.

Differences between the three dongles adopting CS43131 + SGM8262---JCALLY JM20 MAX, Fiio KA11, and Shanling UA Mini---are described nicely at 9:22 through 13;25 in the video. I think the JM20 MAX is the best implementation of the three.

He mentions other dongles, too, including the E1DA 9039S.
 
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I realize that this YouTube video


published by Crinacle pretty much sums up most of the USB dongle DAC/headphone amp devices that ASR members are interested in these days.

Differences between the three dongles adopting CS43131 + SGM8262---JCALLY JM20 MAX, Fiio KA11, and Shanling UA Mini---are described nicely at 9:22 through 13;25 in the video. I think the JM20 MAX is the best implementation of the three.

He mentions other dongles, too, including the E1DA 9039S.
curious did u received your TRN Black Pearl, For me you be surprised, yestarday change to AB dac setting to see on 4.5mm balanced port with adapter to my kiwi ears ellipse strange sound cracking and make so hot when crank volume on my phone, I buy and change cable on my kiwi ears ellipse with Tripowin GranVia only 3.5 in end curious did maybe deserve get 4.5mm unbalanced with TRN Black Pearl to say with my adapter somehow sound better just this cracking no idea why and make hot is great dac so surprised compared with boring JM20 Max .Be nice u test when u received TRN Black Pearl is great whatever i throw to him just dont know how to do measurements use him with my Kiwi Ears Ellipse and Edifier M60 sound fantastic
 
curious did u received your TRN Black Pearl,
Like @mc.god said, the one I received is DOA.

For me you be surprised, yestarday change to AB dac setting to see on 4.5mm balanced port with adapter to my kiwi ears ellipse strange sound cracking and make so hot when crank volume on my phone, I buy and change cable on my kiwi ears ellipse with Tripowin GranVia only 3.5 in end curious did maybe deserve get 4.5mm unbalanced with TRN Black Pearl to say with my adapter somehow sound better just this cracking no idea why and make hot is great dac so surprised compared with boring JM20 Max .Be nice u test when u received TRN Black Pearl is great whatever i throw to him just dont know how to do measurements use him with my Kiwi Ears Ellipse and Edifier M60 sound fantastic
Never use a 4.4mm male to 3.5mm (or 6.35mm) female adapter to connect an unbalanced headphone cable to a balanced amp output. It does NOT work as intended, and depending on the adapter pin wiring, it can kill the DAC/amp.
 
I just hope the JM20 Max works in exclusive mode in UAPP on my old Android device. My Tanchjim Space did, but not my Meizu HiFi (non-pro) for some reason. JM12 with JA11 firmware does, as well as Apple and Samsung dongles; but not the CX31993 dongles I've tried. Dunno why.
Got mine and yes, it does work in exclusive mode in UAPP on my Android device. And it doesn't crackle when it's connected and I plug something into the headphone jack. And it doesn't autoplay or bring up google assistant or whatever. The CX-based dongles always did this. And it sounds clean with that audio polarity rumble test clip. Happy with it so far.
 
Like @mc.god said, the one I received is DOA.


Never use a 4.4mm male to 3.5mm (or 6.35mm) female adapter to connect an unbalanced headphone cable to a balanced amp output. It does NOT work as intended, and depending on the adapter pin wiring, it can kill the DAC/amp.
Thanks maybe need buy cable for my Kiwi Ears Ellipse really so like this headphones with this dac what i hear on 4.5mm adapter to 3.5mm Tripowin GranVia is better not much use 4.5mm since in past have order Hilidac Audirect Beam 2S to use with my Sony MDR-1AM2 now think be get cable from Tripowin Nova i think or maybe again Tripowin GranVia which i have and use now with my Ellipse only is 3.5mm because when order him dont think be buy 4.5mm dac and is great cable, did u think be good cable 4.5mm to double mono on the headphones be first 4.4mm cable to buy to see how can be.Be try mine Sony MDR1AM2 with 4.5mm from the sony only to find cable haha is be many years.
Sorry your TRN come dead hmm where u order your did direct from Linsoul website like me
 
Differences between the three dongles adopting CS43131 + SGM8262---JCALLY JM20 MAX, Fiio KA11, and Shanling UA Mini---are described nicely at 9:22 through 13;25 in the video. I think the JM20 MAX is the best implementation of the three.

He mentions other dongles, too, including the E1DA 9039S.

Pretty much the only thing the KA11 has is the ability to choose output filters including NOS through the Fiio Control app, which is pretty much a useless feature.

Ergonomically and cost-wise the MAX is so much more superior. The warm electronics are housed at the port instead of the 3.5mm tail which is makes it way more comfortable to use than the KA11. I also got mine almost half the price of the KA11.
 
Due to a lack of possibilities for testing and measuring, I can only give a purely subjective judgment: Sounds very good.

And that with all the headphones I have connected.

PXL_20250504_145410960~2.jpg


BUT: Not all smartphones work perfectly with the standard OS.

Xiaomi 13T Pro and 15 Ultra play flawlessly and cleanly.

Pixel 7 Pro and Pixel 8 Pro with the latest Android version produce annoying noise.

Occasional crackling, which is equally noticeable when streaming and playing files on the phone.

Not the fault of the dongle, but worth mentioning.
 
Morning guys currious did anyone order or have this dac look so great to me maybe step up from my current TRN Black Pearl which i am so happy using with my Kiwi Ears Ellipse on 4.4mm balanced jack incredible power and separation on instruments i currious the new SMSL DS 20 i see only people speak on Headfi only here no theme or any info for me look this be great dac for anyone most iphone users and android so currious to someone get more details i maybe be order one next souple months because is so interesting only be interesting see your opinion https://www.linsoul.com/products/smsl-ds20
Product highlights 
  • Quad-CS43131 DAC configuration
  • Fully balanced PLFC headphone amplifier circuit
  • Native DSD256 and PCM up to 32-bit/768kHz
  • MQA full decoding
  • Dedicated low-noise power supply and clock circuit
  • USB 1.1 mode supports PS4, PS5, and Switch
  • Dual headphone outputs: 3.5mm single-ended and 4.4mm balanced
  • 6000mAh battery with USB-C input (5V/9V/12V support)
  • Compact, magnetically shielded aluminum chassis
  • Output power up to 500mW ×2 into 32Ω
  • Dynamic range and SNR: 126dB on both outputs
  • Output impedance: approx. 0Ω
Specs
  • DAC chips: 4× Cirrus Logic CS43131
  • USB receiver: 3rd Gen XMOS XU-316
  • USB transmission: Asynchronous
  • Compatibility: Windows 7/8/8.1/10/11, macOS, Linux, Android, iOS, PS4, PS5, Nintendo Switch
  • Bit depth: 1bit, 16–32bit
  • Sampling rate:
    • PCM: 44.1–768kHz
    • DSD: 2.8224–11.2896MHz (DSD64–DSD256)
  • Output impedance: Approx. 0Ω
    • THD+N (unweighted): 0.0002% at 300Ω
    • Output power:
    • 16Ω: 500mW ×2
    • 32Ω: 500mW ×2
    • 64Ω: 350mW ×2
    • 150Ω: 240mW ×2
    • 300Ω: 120mW ×2
    • 600Ω: 60mW ×2
  • Dynamic range: 126dB (3.5mm and 4.4mm)
  • SNR: 126dB (3.5mm and 4.4mm)
  • Battery: 6000mAh / 3.7V (22.2Wh)
  • Size: 2.8in × 0.67in × 4.7in (71 × 17 × 118.5mm)
  • Weight: 0.61lbs (275g)
  • Inputs: USB-C
  • Outputs: 3.5mm headphone, 4.4mm balanced headphone
  • Controls:
    • Function button: volume adjust, USB1.1/2.0 toggle (short press)
    • Power button: long press for shutdown
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So with the JM20 Max, there is a very short 'fade in' when I start playing something on it in either Windows or on Android (I use UAPP with the dongle in exclusive mode). It's easiest to tell with the Windows 'test' chimes. It's something I've been noticing with some music and wasn't sure if it was the dongle or just the songs, but yes, it's for sure just behaviour of the dongle. This is... disappointing.
 
So with the JM20 Max, there is a very short 'fade in' when I start playing something on it in either Windows or on Android (I use UAPP with the dongle in exclusive mode). It's easiest to tell with the Windows 'test' chimes. It's something I've been noticing with some music and wasn't sure if it was the dongle or just the songs, but yes, it's for sure just behaviour of the dongle. This is... disappointing.
Are you sure? As reported here, according to my test, anything played from the JM20 Max does not fade in. It is fine with Windows 'test' chimes, too. I wonder about your Windows setting.
 
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BUT: Not all smartphones work perfectly with the standard OS.

Xiaomi 13T Pro and 15 Ultra play flawlessly and cleanly.

Pixel 7 Pro and Pixel 8 Pro with the latest Android version produce annoying noise.

Occasional crackling, which is equally noticeable when streaming and playing files on the phone.

Not the fault of the dongle, but worth mentioning.

It works perfectly on my Pixel 8 Pro via Tidal or YT Music. Maybe you've got some software settings you need to update.

BTW, that SMSL is really pushing on the boundary of a "portable" device.
 
Are you sure? As reported here, according to my test, anything played from the JM20 does not fade in. It is fine with Windows 'test' chimes, too. I wonder about your Windows setting.
As I said, the dongle has the same behaviour on my Android device (exclusive mode in UAPP). What is the Windows setting to which you are referring? Having EQ APO installed for the device?

Quickly testing other dongles I have on hand:

Apple dongle: fade in
Jcally JM12 (JA11 firmware): start of audio is truncated
Jcally JM12 (TinHifi firmware): audio starts normally
Jcally JM6, VE Abigail: audio starts normally
JCally JM20 Max: fade in
Meizu HiFi (non-pro): fade in
Samsung: audio starts normally
 
As I said, the dongle has the same behaviour on my Android device (exclusive mode in UAPP). What is the Windows setting to which you are referring? Having EQ APO installed for the device?

Quickly testing other dongles I have on hand:

Apple dongle: fade in
Jcally JM12 (JA11 firmware): start of audio is truncated
Jcally JM12 (TinHifi firmware): audio starts normally
Jcally JM6, VE Abigail: audio starts normally
JCally JM20 Max: fade in
Meizu HiFi (non-pro): fade in
Samsung: audio starts normally
That is very weird. There is no fade-in from both the JM20 and JM20 Max that I have. Tried both my Windows 11 PC and Android phone (no UAPP, though). Puzzling indeed.

I did not mean any specific settings. Just wondered what would be different between your environment and mine.

I think we need input from others owning this dongle.
 
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Have mine, JM20MAX, from November 1, 2024.

Not die. Use it every day on PC with the HE400SE (and superlus hd330). Can be a little hot sometimes. On lg v50 use it with Neutron player.

20-80% loudness. 100% only for classical music or some jazz. Or EQ with -preamps)

Greate device.

One problem: when you connect it to a PC USB port and near is USB Wi Fi... Sound stops for half a second or a second. And then play normally. If I download a torrent, it happens very often. Every 10-20 seconds or less...

With a LAN cable, it works fine)

Ordered e1da 9039s for the endgame of all games.

Can it surprise me after Jcally?)
 

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