JCALLY JM20 MAX Headphone Dongle Review

[Grotti]

May be a little bit of topic but does anybody know of a reliable source in the EU? If so, please send me a PM.

 

[DanielT]

Thanks for the test Amir.

It's incredible what you can get for the price of a hamburger menu for two.

If I had been in need of a headphone dongle, I would have had no hesitation in buying this JCALLY JM20 MAX.

 

[RickS]

Incorrect information. These are the specs of the standard JM20, not the JM20 MAX.

Correct specs from the product page:
View attachment 444935

Thanks, fixed!

 

[sabih]

I have this dongle and listening to it reminds of sound quality I used to get from Denon CD Player. Although Denon CD player sound was more polished [I don't know why].
I knew that this dongle is incredible for the price just by listening to sound quality. The same has now been confirmed by review.

My mind is still struggling to answer one question, which is how does denon and marantz equipment sound so polished without winning in all these tests and measurements.
Maybe these japanese brands know something else about sound quality apart from just objective measurements.

Another question is why some Japanese Pioneer, Denon and Marantz still sound so sweet and musical when directly compared to TPA3255 highest performing amps?

 

[thehague]

I’m using this one with the Truthear GATE IEM’s and it sounds absolutely wonderful.

 

[DanielT]

I have this dongle and listening to it reminds of sound quality I used to get from Denon CD Player. Although Denon CD player sound was more polished [I don't know why].
I knew that this dongle is incredible for the price just by listening to sound quality. The same has now been confirmed by review.

My mind is still struggling to answer one question, which is how does denon and marantz equipment sound so polished without winning in all these tests and measurements.
Maybe these japanese brands know something else about sound quality apart from just objective measurements.

Another question is why some Japanese Pioneer, Denon and Marantz still sound so sweet and musical when directly compared to TPA3255 highest performing amps?

My guess. You listened at different volumes and or had preconceived ideas about how it would sound. That subjective bias thing is easy to fall for. I can do it myself if I don't think about it.

When I blind tested: Blu-ray Sony BDP-S570 vs CD-player Marantz CD5001 vs Blu-ray Denon DBP-2012UD a few years ago, I found zero differences, nada, nothing. I couldn't tell them apart. And believe me I really tried, full concentration and so on but ...nada:
(You had poor HiFi when you tested, hence the result. I don't buy that argument.)

What is this? No golden ears!

Got an idea last week. Connected a Blu-ray, Sony BDP-S570, and a CD- player Marantz CD5001 to the pre amp. It has line selectors. Went to the local flea market and managed to find duplicates, CDs. Exactly the same CDs, the same recording on the discs. Same master. Enter with the discs in the...

audiosciencereview.com

If you want to blind test yourself, for example op amps, which are so very popular among Hifi subjectivists to hear huge differences between (not saying you are one), you can do this here:

Can you hear a difference between OPA2134 and LME49720 in the PRE-TC10?

The op-amps OPA2134 and LME49720 were swapped in the Audiophonics PRE-TC10 preamp and the files (matched and aligned) were recorded and uploaded to: https://drive.google.com/file/d/1CI7NjcYyL323qeCFDxj3MtSkfcfu4GNU/view?usp=sharing Can you hear any difference? This is how they measure: And...

audiosciencereview.com

Here is an interesting document which, among other things, addresses the topic of our limits of audibility:

SINAD Audio Audibility Analysis

SINAD in Audio Electronics: Technical Significance and Audibility in a Living Room Context 1. Introduction Overview: The specification SINAD, an acronym for Signal-to-Noise and Distortion ratio, frequently appears in the technical documentation and reviews of audio electronic components such as D...

docs.google.com

 

[sabih]

My guess. You listened at different volumes and or had preconceived ideas about how it would sound. That subjective bias thing is easy to fall for. I can do it myself if I don't think about it.

When I blind tested: Blu-ray, Sony BDP-S570 vs CD-player Marantz CD5001 vs Denon DBP-2012UD a few years ago, I found zero differences, nada, nothing. I couldn't tell them apart.

What is this? No golden ears!

Got an idea last week. Connected a Blu-ray, Sony BDP-S570, and a CD- player Marantz CD5001 to the pre amp. It has line selectors. Went to the local flea market and managed to find duplicates, CDs. Exactly the same CDs, the same recording on the discs. Same master. Enter with the discs in the...

audiosciencereview.com

If you want to blind test yourself, for example op amps, which are so very popular among Hifi subjectivists to hear huge differences between (not saying you are one), you can do this:

Can you hear a difference between OPA2134 and LME49720 in the PRE-TC10?

The op-amps OPA2134 and LME49720 were swapped in the Audiophonics PRE-TC10 preamp and the files (matched and aligned) were recorded and uploaded to: https://drive.google.com/file/d/1CI7NjcYyL323qeCFDxj3MtSkfcfu4GNU/view?usp=sharing Can you hear any difference? This is how they measure: And...

audiosciencereview.com

Here is an interesting document that addresses this with the limits of audibility:

SINAD Audio Audibility Analysis

SINAD in Audio Electronics: Technical Significance and Audibility in a Living Room Context 1. Introduction Overview: The specification SINAD, an acronym for Signal-to-Noise and Distortion ratio, frequently appears in the technical documentation and reviews of audio electronic components such as D...

docs.google.com

I agree with your point. But my concern is a litte different. Being an audiophile for so many years and listening to so much stuff. I am still confused.

Some audio manufacturers have their house sound.
example Yamaha have their typical tonal color and punch. People who love Yamaha knows what I am talking about.
this statement is somewhat true with other companies as well.

But chinese manufacturers are not focusing on sound characteristics/tonal color to get associated with their brand. Their main goal is to be as neutral as possible.
One of the most engaging sound amplifier that I have heard was from Nakamichi Japan [1990s era]. It was fairly distorted sound and far away from neutrality. But still was the most enjoyable.

My main concern is that we are fighting to get the most refined form of water. But does drinking refined water give same level of Satisfaction that we get from drinking Juice?

 

[DanielT]

I agree with your point. But my concern is a litte different. Being an audiophile for so many years and listening to so much stuff. I am still confused.

I can be confused by one thing or the other. Like I managed to literally paint myself into a corner a few days ago. I got paint on one foot and couldn't wash it off, forgot to put plastic slippers outside the painting area. It required creativity to solve that dilemma.

With Hifi the same there, I can be confused about how, what should I take... for example how EPDR works. But then I try to educate myself, for example via threads like this:

Stereophile has started calculating EPDR.

https://www.stereophile.com/content/goldenear-brx-bookshelf-reference-x-loudspeaker-measurements And he is going back to previous reviews and adding this in. EPDR (Equivalent Peak Dissipation Resistance) takes the impedance and phase data and computes a new impedance that shows what equivalent...

audiosciencereview.com

Some audio manufacturers have their house sound.
example Yamaha have their typical tonal color and punch. People who love Yamaha knows what I am talking about.
this statement is somewhat true with other companies as well.

Concepts or ideas of how Yamaha sounds BUT they don't sound anything. Exactly as it should be. Yamaha amplifiers ... amplify the signal without adding any sound signature, without coloring the sound/signal. At least with Yamaha amplifiers with ToP-ART technology, which has been around since around the early 1990s. Before that, what their amplifiers produced was most likely in the form of SINAD below audibility limits.

Edit:
Compare that to the distortion of the speakers, in that link I pasted in # 47. Just to put into perspective what you can hear.

With these you should hear the distortion despite masking and so on, but then we are talking about 8% distortion in the area we are most sensitive to distortion:

Erin reviews GR-Research NX-Bravo

Short snippets from the review: - on axis is really bad, but it evens out by 15 degrees off axis - super wide dispersion up to around 4k, then narrows quickly - very high distortion from the tweeter (1% H4/H5 around 2k at 86dB/1m) - super clean decay behavior Overall, it's... Fine, I guess...

audiosciencereview.com

 

[peniku8]

The in my opinion most important characteristic of a dongle like that (output impedance) is missing.
They also don't list it in the specs so I would never buy this product based off specs or this review.
Output impedance (nowadays) has the biggest impact on perceived sound, since it being bad alters the frequency response of some IEMs (and does pretty much not matter to the single driver ones). Far more than a change from 120dB to 80dB SINAD ever could.
With so many popular IEMs on the market with problematic impedances (such as the Crinacle Zero Red, Blue and Blue 2) I think the inclusion of an output impedance test is essential to every headphone amplifier/dongle review.
The SINAD vs impedance measurements give a clue where to expect that value for this dongle (somewhere below 2 Ohm I guess?), but having the actual test would be a valuable addition to ASR reviews imo.
@amirm what do you think?

 

[Music1969]

Added to the review. The test was already run but I forgot to included in the review.

Thanks!

 

[somebodyelse]

The in my opinion most important characteristic of a dongle like that (output impedance) is missing.

If the output impedance was significant the 'Distortion + noise vs. Output voltage' plots would separate for low load impedance rather than stacking as they do.

 

[multiformous]

The in my opinion most important characteristic of a dongle like that (output impedance) is missing.
They also don't list it in the specs so I would never buy this product based off specs or this review.
Output impedance (nowadays) has the biggest impact on perceived sound, since it being bad alters the frequency response of some IEMs (and does pretty much not matter to the single driver ones). Far more than a change from 120dB to 80dB SINAD ever could.
With so many popular IEMs on the market with problematic impedances (such as the Crinacle Zero Red, Blue and Blue 2) I think the inclusion of an output impedance test is essential to every headphone amplifier/dongle review.
The SINAD vs impedance measurements give a clue where to expect that value for this dongle (somewhere below 2 Ohm I guess?), but having the actual test would be a valuable addition to ASR reviews imo.
@amirm what do you think?

Output impedance measured to be just under 0.6 ohms here.

 

[peniku8]

If the output impedance was significant the 'Distortion + noise vs. Output voltage' plots would separate for low load impedance rather than stacking as they do.

Which I mentioned near the end of my comment, correct

 

[jkim]

Output impedance measured to be just under 0.6 ohms here.

That's right.

@MC_RME also reported his output impedance measurements in my review thread.

It seems that many members read Amir's reviews only.

Although I understand why, this is somewhat discouraging as my motivation was to share valuable findings with more fellow audio enthusiasts...

 

[Zek]

One noob question: can the JM20 Max be used as a desktop DAC, i.e. can the output be connected to active boxes or an amplifier?

 

[peniku8]

That's right.

@MC_RME also reported his output impedance measurements in my review thread.

It seems that many members read Amir's reviews only.

Although I understand why, this is somewhat discouraging as my motivation was to share valuable findings with more fellow audio enthusiasts...

I think most members just casually browse the pinned posts to see whats being tested, while they only look deeper into the forums if they actually want to buy something. At least that's how it is for me. I work in audio professionally so I only buy something when it's actually on the list of 'improves my workflow' or 'improves my asking rates'.

 

[staticV3]

One noob question: can the JM20 Max be used as a desktop DAC, i.e. can the output be connected to active boxes or an amplifier?

Every 3.5mm and 1/4" headphone output can be connected to an external Amp, Monitor, Preamp, Mixer, AVR etc.

There are no exceptions.

 

[lucian]

cant find out what the difference is between the MAX and PRO version. anyone can elaborate?

 

[rinzler.0x]

I agree with your point. But my concern is a litte different. Being an audiophile for so many years and listening to so much stuff. I am still confused.

Some audio manufacturers have their house sound.
example Yamaha have their typical tonal color and punch. People who love Yamaha knows what I am talking about.
this statement is somewhat true with other companies as well.

But chinese manufacturers are not focusing on sound characteristics/tonal color to get associated with their brand. Their main goal is to be as neutral as possible.
One of the most engaging sound amplifier that I have heard was from Nakamichi Japan [1990s era]. It was fairly distorted sound and far away from neutrality. But still was the most enjoyable.

My main concern is that we are fighting to get the most refined form of water. But does drinking refined water give same level of Satisfaction that we get from drinking Juice?

I mean why would you want a colored dac in the first place? When you can add tube amps or analog eq after that? It doesn't make sense to me at all, chinese manufacturers are right to make their dac as neutral or accurate as possible lol

 

[Aperiodic]

Bought the first gen and it stopped working soon after purchase, I think I'm outta the Dongle Of The Week Club. My '$9 phone dongle' just keeps working, unlike any of those I have bought to replace it.