CHORD Mojo 2 Review (Portable DAC & HP Amp)

[maverickronin]

I click the crossfeed button on my player on PC/Phone. 0$.

System wide? Gives the same result with a wide variety of source devices?

Yes it's possible, but generally hardware is more convenient and reliable.

 

[amirm]

There is no analog line out, right? Can your run the headphone out into an external preamp/amp in one's home system?

Of course. That is how I tested it "as a DAC." But be sure to not max out the volume as not only that will clip on its own, but will overdrive the external amplifier.

 

[norcalscott]

Put me in the camp of not fully understanding the need for this. It is a great device and all, but for that cost it really should be able to drive any headphone to a decent volume level. I have a FiiO portable DAC, and a collection of dongles, and an LG G7 that now is relegated to DAP duty, but when I travel I find myself either taking my HiBy R5, which has 256GB of dedicated music files on it (and it is slightly smaller than this DAC), or I just take my phone and use Bluetooth earbuds. I’ve got to believe the market for these portable DACs is pretty small these days.

 

[amirm]

I think of this device as something to you take from home to work and back. Just plug in and it works to drive your headphones. And you don't leave it behind as to get stolen and such. For on the road use, it is too heavy for me. I would use a dongle before using this.

 

[Katji]

Also it seems the battery is not replaceable, which is an absolute no-go for a $800 audio product, which in contrast to a smartphone can be used several decades. Thankfully the European Union is preparing an initiative against devices with not replaceable batteries.

That's the confirmation I needed - off to the top to do the Poor vote now.

 

[Nango]

Battery drain is minimal using either BT or wired earphones. What drains a phone most is the screen, especially if you play any video.

Don't know how much it drains but 100mA will drain 4x higher than my 25mA dongle in use this I know.

 

[dtaylo1066]

Of course. That is how I tested it "as a DAC." But be sure to not max out the volume as not only that will clip on its own, but will overdrive the external amplifier.

Thanks for reply. Approximately what volume level did you set it at when testing as DAC?

 

[Moderate Dionysianism]

This is why I've been screaming about the V60 as the best DAP alternative for low to moderate impedance iem or cans. No dongle required (ESS9219 as found in Tempotec, Fiio, Shanling and Qudelix devices), 70 hrs battery life, 1.9vrms output (says LG) LDAC if you want. Need a fairly large pocket though. In high impedance mode drives my HE-4XX just fine.

I actually have the V40, but I still connect the NX4 to it, because the jack of the HD 25 wiggles in the socket when walking around, disconnecting one channel. Same happens with my PortaPro. It's not due to wear of the socket/jacks - been happening since the phone was brand new, and there is no such issue with the Topping. Interestingly my Aurvanas and all 3-pole jacks (HPs with mic) stay connected just fine. I'm starting to suspect there must be some sub-milimeter-level size differencess between the jacks, which the socket doesn"t accommodate. Super annoying tbh.

And then there's that stupid impedance sensing feature. For example it won't go loud enough with the CAL! in the 'normal device' mode, and when you trick it into high gain with an adapter you get an extra bit sticking out of your pocket, getting tangled in clothes etc...

Maybe I'm nitpicking, but true portability is all about such minute stuff that doesn"t come into play with desktop use.


Sorry for the offtopic. The Chord is indeed interesting, nice to see it measure fine. I'm not in the market, but I"d like to see the DSP feature tested/explored, at least see whether it impacts the results when active vs. bypassed.

 

[Chester]

Also it seems the battery is not replaceable, which is an absolute no-go for a $800 audio product, which in contrast to a smartphone can be used several decades. Thankfully the European Union is preparing an initiative against devices with not replaceable batteries.

Are you sure about this? I thought the battery was shown to be replaceable, given the connection used.

 

[Jmudrick]

I actually have the V40, but I still connect the NX4 to it, because the jack of the HD 25 wiggles in the socket when walking around, disconnecting one channel. Same happens with my PortaPro. It's not due to wear of the socket/jacks - been happening since the phone was brand new, and there is no such issue with the Topping. Interestingly my Aurvanas and all 3-pole jacks (HPs with mic) stay connected just fine. I'm starting to suspect there must be some sub-milimeter-level size differencess between the jacks, which the socket doesn"t accommodate. Super annoying tbh.

And then there's that stupid impedance sensing feature. For example it won't go loud enough with the CAL! in the 'normal device' mode, and when you trick it into high gain with an adapter you get an extra bit sticking out of your pocket, getting tangled in clothes etc...

Maybe I'm nitpicking, but true portability is all about such minute stuff that doesn"t come into play with desktop use.


Sorry for the offtopic. The Chord is indeed interesting, nice to see it measure fine. I'm not in the market, but I"d like to see the DSP feature tested/explored, at least see whether it impacts the results when active vs. bypassed.

You're right about the impedance sensing thing. Not really an issue with my IEMs which get enough volume, but it's a minor annoyance if I want to crank the 4xx cans... but generally I'm sitting on my chair or bed with the cans so the V60 doesn't need to be shirt pocketable (it's not anyway, it's much bigger than the V30). The jack gets funky when the phone is cased but has been fine bareback. Nothing's perfect of course, and I use the V60 mostly at home or in the car where its quirks are more manageable than jogging or at the gym . I know , off track.

 

[The Jniac]

Why does the filter not start until ~22kHz? Would it not make more sense to start at 20kHz or 21kHz so that you have full attenuation before reaching nyquist?

 

[amirm]

Thanks for reply. Approximately what volume level did you set it at when testing as DAC?

I think I clicked down 5 or 6 times from max on the unit.

 

[amirm]

Why does the filter not start until ~22kHz? Would it not make more sense to start at 20kHz or 21kHz so that you have full attenuation before reaching nyquist?

It is to respect the sampling rate. CD is 44100 so a theoretical filter would everything below 22.05 kHz alone but truncate heavily after. In other words, the format has some bandwidth headroom and this filter preserves that.

 

[amirm]

Well, that makes it poor, doesn't it? What's the point of a super-steep filter if still doesn't reach full attenuation at Nyquist?

That measurement/graph lacks resolution in that region given how steep the change is. So I would go by what the filter looks like than exact value of cursor.

 

[AudioSceptic]

It is to respect the sampling rate. CD is 44100 so a theoretical filter would everything below 22.05 kHz alone but truncate heavily after. In other words, the format has some bandwidth headroom and this filter preserves that.

The point, which I also made, is that the FR needs to be flat only to ~20 kHz. There is no need for anything above that, so we have 2 kHz to reach full attenuation at Nyquist, which bizarrely this fails to do (unless your graph is misleading, of course).

Edit: just read your reply to my earlier post. Just what is the +/- error in those measurements/graphs?

 

[AudioSceptic]

I actually have the V40, but I still connect the NX4 to it, because the jack of the HD 25 wiggles in the socket when walking around, disconnecting one channel. Same happens with my PortaPro. It's not due to wear of the socket/jacks - been happening since the phone was brand new, and there is no such issue with the Topping. Interestingly my Aurvanas and all 3-pole jacks (HPs with mic) stay connected just fine. I'm starting to suspect there must be some sub-milimeter-level size differencess between the jacks, which the socket doesn"t accommodate. Super annoying tbh.

Wild guess, but could this be something as stupid as an imperial/metric mistake? The full-size TRS is ¼" or exactly 6.35 mm. The mini is specified as 3.5 mm, but is often called ⅛", which is actually 3.175 mm. Put a ⅛" plug in a 3.5 mm socket and you have a loose fit.

 

[amirm]

Edit: just read your reply to my earlier post. Just what is the +/- error in those measurements/graphs?

The slope had about 10 samples. If I move the cursor to point where there is full attenuation, frequency is about 22.359 kHz. The input signal is random so there can even be run to run variations.

 

[amirm]

The point, which I also made, is that the FR needs to be flat only to ~20 kHz. There is no need for anything above that, so we have 2 kHz to reach full attenuation at Nyquist, which bizarrely this fails to do (unless your graph is misleading, of course).

Human hearing doesn't have a universal 20 kHz shut off. That is just a nominal value. Some young people can hear above that. So again, to respect what the format can do, this type of filter is optimal. In practice of course, what you state would work and no need to spend a lot of money for something this sharp.

 

[AudioSceptic]

The slope had about 10 samples. If I move the cursor to point where there is full attenuation, frequency is about 22.359 kHz. The input signal is random so there can even be run to run variations.

That's cutting it much tighter that it needs to be, isn't?

 

[AudioSceptic]

Human hearing doesn't have a universal 20 kHz shut off. That is just a nominal value. Some young people can hear above that. So again, to respect what the format can do, this type of filter is optimal. In practice of course, what you state would work and no need to spend a lot of money for something this sharp.

Of course, but 20 kHz is a nice round and accepted figure, and I'm betting that most ASR members can't even get close to that, age being a major factor. If Chord can really get that close to 22 and still reach full attenuation at 22.05, then that's great, but still unnecessary. Do you happen to know what the best studio ADCs and DACs can manage in terms of filter slopes?