JCALLY JM20 MAX Headphone Dongle Review

[MC_RME]

Bravo-HD, like with Fosi DS2 and others.

 

[dark132]

It can help prevent ground loops can it not? Plus it allows for 4V output normally. I remember in my previous place I lived I had ground loop issue with JBL 308p speakers and how it was setup with my TV and laptop, but I ended up being able to solve that by using somekind of isolator between the TV aerial and the TV, I don't know how likely it is that people have ground loop problems that can be solved by using a balanced DAC though, but it's one of it's features.

The balanced interface is mainly used to solve the noise problem when connecting cables over long distances. It is over-designed when it is mainly used in mobile phones, because it is impossible to have a connection cable longer than 20cm. The only headphone I have that uses a balanced interface is the hd660, and I will not take it out on the street.

 

[dark132]

Is there an ASIO driver available for the JM20 Max?

I just connected jm20max to pc with a usb to usb-c cable, and it works fine when using all4asio in foobar2000, but I need to set the asio buffer size of all4asio to 1024samples, otherwise the sound will be stuck.

 

[CedarX]

It is over-designed when it is mainly used in mobile phones, because it is impossible to have a connection cable longer than 20cm.

Not really: for portable applications, it’s mostly about getting more power (if needed!) considering the limited available voltage constraint.

 

[dark132]

Using it to drive dt900prox surprisingly feels OK

 

[goldenears]

I just connected jm20max to pc with a usb to usb-c cable, and it works fine when using all4asio in foobar2000, but I need to set the asio buffer size of all4asio to 1024samples, otherwise the sound will be stuck.

I don't want to use asio4all because of the extra latency. I'm planning to use it in a DAW to play VST instruments.

I mean native ASIO drivers.

I looked at the page for the Bravo-HD drivers and it says:

The ASIO output as some limitations:

• It only supports one program at a time

On the JA11 I can have Ableton using the ASIO driver, but still use the DX driver to output sound from Firefox at the same time.

Does anyone know if the Bravo-HD drivers support that when used with the JM20 Max?

 

[dark132]

I don't want to use asio4all because of the extra latency. I'm planning to use it in a DAW to play VST instruments.

I mean native ASIO drivers.

I looked at the page for the Bravo-HD drivers and it says:

On the JA11 I can have Ableton using the ASIO driver, but still use the DX driver to output sound from Firefox at the same time.

Does anyone know if the Bravo-HD drivers support that when used with the JM20 Max?

You can try flexasio, it works ok after setting [output] wasapiExclusiveMode = false

 

[Robbo99999]

The balanced interface is mainly used to solve the noise problem when connecting cables over long distances. It is over-designed when it is mainly used in mobile phones, because it is impossible to have a connection cable longer than 20cm. The only headphone I have that uses a balanced interface is the hd660, and I will not take it out on the street.

DS2 doesn't have to be used with just headphones and you can have ground loops even without long cables.

 

[goldenears]

You can try flexasio, it works ok after setting [output] wasapiExclusiveMode = false

Nah, I can't be bothered messing around with non-native drivers.

I was thinking about checking out the JM20 Max for the higher output and measured accuracy, but I'm happy with the JA11 that has pretty good native ASIO drivers.

 

[Viper780]

Why you need ASIO?

 

[markanini]

Nah, I can't be bothered messing around with non-native drivers.

I was thinking about checking out the JM20 Max for the higher output and measured accuracy, but I'm happy with the JA11 that has pretty good native ASIO drivers.

Cant hurt to try, Flexasio served me well when I didnt ahve options. At least you will know for sure. Strongly recommend using the GUI though or it takes a bit of time to read the docs: https://github.com/flipswitchingmonkey/FlexASIO_GUI

 

[goldark]

Just received my JM20 Max in the mail. Has more than enough power for my HD600, which is EQ'd to Harman with an even bigger bass boost. No problems with audible distortion or volume from my phone or laptop. I no longer have a need for any desktop headphone amp/DAC. Great device!

 

[TheEverydayNightmare]

For Lightning devices, an ordinary adapter to USB-C won't do the trick.

You'll get a pop-up message stating that the connected USB accessory draws too much current.

The solution is an adapter with special MFi chip inside which tells the iPad to supply current to the dongle.

An example: https://www.ddhifi.com/en/product/tc28i-m2/

Is there any other cheaper alternatives, or way to tell whether an adapter has this specific chip? Do you mean that the made for iphone certification means that it allows high current? Or this specific chip(that is also mfi) forces out current? Thanks!

 

[staticV3]

Is there any other cheaper alternatives

Meenova makes cheap adapters with MFi chip.

However, previously Meenova has sold a Lightning to USB-C adapter that for some reason, would output the iPhone's battery voltage directly to VBUS, without boost conversion to 5V.

That can have unforeseen consequences on the dongle DAC, which expects a stable 5V.

The adapter seems to be discontinued now, but I'd still check the VBUS voltage myself with a USB power meter, just to be sure.

In any case, that this is even allowed to happen with Apple's Lightning port is ridiculous, IMO.

or way to tell whether an adapter has this specific chip?

The keyword appears to be "OTG".

So if you see an adapter or adapter cable called "Lightning to USB-C OTG adapter", then it likely unlocks current output to external USB accessories.

If the description or product pictures mention something like "Max output current: 400mA", then this is definitely a cable with OTG capabilities.

Yes, different OTG MFi chips exist with different current limits. Exceed it, and the iPhone will cut the USB connection and throw the "Connected accessory draws too much current" warning.

You'd think that an OTG cable with 400mA MFi chip would enable 400mA regardless of which Lighting iPhone you use it with, but no. There are differences between iPhone models.

The iPhone X for example seems especially temperamental and will refuse to work with OTG cable+dongle DAC combos that work just fine on other iPhones.

Do you mean that the made for iphone certification means that it allows high current?

Different types of MFi chips exist.

If you see a regular charging cable with MFi logo, then that just means that you can charge your iPhone with it, without a pop-up appearing warning you about the cable's authenticity or w/e.

That cable will not enable current output to external USB accessories though.

For that, a different MFi chip is required, the presence of which is usually indicated by "OTG" in the name.

 

[TheEverydayNightmare]

How much battery can I expect it to use up in x amount of time? I'm mostly worried about stressing out my battery, since I'm probably gonna be running my new DC Aeon 2 Closed through it, which is supposedly?? notorious for being current hungry, and I also don't wanna lose my phone battery too quickly. And also since the jm20 maxes clip at ~1.6 Vrms @ 12 ohms, I'm not sure how they'll fare (as in I'm not sure how to do the math lol), if the amount of current needed might be stressful. Thanks! Also I have an iPhone 13 Pro if that helps. If I can't with my phone, I'll probably only use it with my MacBook anyways since I mostly wanna use it for music production.

 

[CedarX]

How much battery can I expect it to use up in x amount of time? I'm mostly worried about stressing out my battery, since I'm probably gonna be running my new DC Aeon 2 Closed through it, which is supposedly?? notorious for being current hungry, and I also don't wanna lose my phone battery too quickly. And also since the jm20 maxes clip at ~1.6 Vrms @ 12 ohms, I'm not sure how they'll fare (as in I'm not sure how to do the math lol), if the amount of current needed might be stressful. Thanks! Also I have an iPhone 13 Pro if that helps. If I can't with my phone, I'll probably only use it with my MacBook anyways since I mostly wanna use it for music production.

If battery usage is a concern for you, would something like a Qudelix 5K be a better choice? Sure it’s more expensive, but it has its own battery and you’ll get BT in addition to USB input + the equivalent of a system-wide PEQ for your iPhone.

 

[TheEverydayNightmare]

If battery usage is a concern for you, would something like a Qudelix 5K be a better choice? Sure it’s more expensive, but it has its own battery and you’ll get BT in addition to USB input + the equivalent of a system-wide PEQ for your iPhone.

Yeah, actually the only thing that’s stopping me from the Qudelix(besides the cost) is the fact that it has bluetooth and a battery. I don’t wanna think about how if my dac amp fails me, then I can’t listen to music(but ig it’s the same problem if I use a lot of my phones battery ), so I guess at this point it’s mostly cost. I mean I already spent 450 on my AC2’s, and I’d prefer not to spend that much more…

 

[Somafunk]

Don't "technically" need it as I have the Moondrop Echo-B USB C 4.4mm dongle and a Aful Snowy Night dongle 4.4mm/3.5mm with USB C cable + OTG Lightning cable but for £21 for this dongle I couldn't resist.

 

[goldenears]

Why you need ASIO?

For the lowest latency for playing VSTs in Ableton Live.

 

[dark132]

How much battery can I expect it to use up in x amount of time? I'm mostly worried about stressing out my battery, since I'm probably gonna be running my new DC Aeon 2 Closed through it, which is supposedly?? notorious for being current hungry, and I also don't wanna lose my phone battery too quickly. And also since the jm20 maxes clip at ~1.6 Vrms @ 12 ohms, I'm not sure how they'll fare (as in I'm not sure how to do the math lol), if the amount of current needed might be stressful. Thanks! Also I have an iPhone 13 Pro if that helps. If I can't with my phone, I'll probably only use it with my MacBook anyways since I mostly wanna use it for music production.

When listening to music, you can turn off the screen to save power. Of course, a better way is to use an old unused mobile phone as a player.