Chord Mojo(1) DAC-amp ☆★►FAQ in 3rd post!◄★☆
Dec 1, 2015 at 10:53 PM Post #6,106 of 42,758
Two major shops says the Mojo cannot push the HD800 properly. My friend tried it and it couldnt.
 
absolute and complete nonsense....both the hugo and the mojo drive the hd800 beautifully without any issue...and sound terrific
 
Dec 1, 2015 at 11:01 PM Post #6,107 of 42,758
[COLOR=B22222]Two major shops says the Mojo cannot push the HD800 properly. My friend tried it and it couldnt.[/COLOR]

absolute and complete nonsense....both the hugo and the mojo drive the hd800 beautifully without any issue...and sound terrific
Sorry to have a different opinion. Please enjoy the Mojo.
 
Dec 1, 2015 at 11:20 PM Post #6,110 of 42,758
I think I measured over 7v, but haven't tried it with Hd-800s. Can anyone confirm?

Yup, I measured it myself and getting 7V at max volume also. I PMed Rob Watts about this becuase he said Mojo's maximum output voltage is 5.3Vrms. He said a DMM does not measure true RMS value. 
 
If we are to Assume 7V we are getting is just the Peak Voltage. Then the true RMS value is still around 5Vrms.
 
In comparison to other DAPs and portable DAC/Amps I have, the voltage I measured never get close to their published spec. (Only Fiio X5 comes close).
 
So yeah it is amazing how much juice the Mojo can push out considering it's size.


Mojo has a lot of headroom for HD800. I could not push the volume past solid blue. Same goes with T1
 
Dec 2, 2015 at 12:15 AM Post #6,111 of 42,758
 
Yup, I measured it myself and getting 7V at max volume also. I PMed Rob Watts about this becuase he said Mojo's maximum output voltage is 5.3Vrms. He said a DMM does not measure true RMS value. 
 
If we are to Assume 7V we are getting is just the Peak Voltage. Then the true RMS value is still around 5Vrms.
 
In comparison to other DAPs and portable DAC/Amps I have, the voltage I measured never get close to their published spec. (Only Fiio X5 comes close).
 
So yeah it is amazing how much juice the Mojo can push out considering it's size.


Mojo has a lot of headroom for HD800. I could not push the volume past solid blue. Same goes with T1

 
On 1kHz 0dBFS signal, Mojo's volume caps out at around 14-15V p-p, so around 5Vrms unloaded.
 
You can say the transient ceiling voltage is around 7Vrms where the signal is really squashed (i.e. a square wave) which is what most multimeters would show, while a true sine wave RMS would be close to 5.3Vrms as quoted with minimal distortion.
 
You can see what I mean on the below graphs as the volume is progressively increased. Big number being the DMM RMS
 
If people find Mojo doesn't work well with HD800 or T1, it's probably not due to the lack of power but purely a sonic preference, because even most big desktop amps can't deliver as much driving power as the Mojo can.
 

 
Dec 2, 2015 at 12:45 AM Post #6,112 of 42,758
   
On 1kHz 0dBFS signal, Mojo's volume caps out at around 14-15V p-p, so around 5Vrms unloaded.
 
You can say the transient ceiling voltage is around 7Vrms where the signal is really squashed (i.e. a square wave) which is what most multimeters would show, while a true sine wave RMS would be close to 5.3Vrms as quoted with minimal distortion.
 
You can see what I mean on the below graphs as the volume is progressively increased. Big number being the DMM RMS
 
If people find Mojo doesn't work well with HD800 or T1, it's probably not due to the lack of power but purely a sonic preference, because even most big desktop amps can't deliver as much driving power as the Mojo can.
 

 
Exactly, based on your graph 5Vrms output is achievable without distotion/clipping. This translates to 116dB into HD800 and 118dB into T1. More than enough to drive both cans with authority. So I agree about people saying "Mojo is not enough" to drive these cans is describing their personal preference with the pairing and not the power output.
 
Dec 2, 2015 at 12:47 AM Post #6,113 of 42,758
  I sent back my original Mojo due to the white noise (hiss?) problem, and I just got a replacement unit.
 
FYI my original unit had audible shhhh noise if I powered it up with just the IEM plugged in and nothing else. The noise level was not dependent on the volume position.
Plugging in a USB cable to the data port brought the noise down by a lot, but still audible.
 
 
The new replacement unit has absolutely no noise as far as I can tell. It's fantastic.


You had the exact same problem my first Mojo had - the USB part was odd - but my replacement unit is perfect - pitch black. And I have to agree with some of the others - my SE846s sound pretty amazing through this little devil. This combination rewards a pristine recording with an experience difficult to match. (Although I was pleasantly surprised exchanging my Mojo for my International+ Optical - also an awfully nice sounding combo)
 
Dec 2, 2015 at 1:18 AM Post #6,114 of 42,758
  Exactly, based on your graph 5Vrms output is achievable without distotion/clipping. This translates to 116dB into HD800 and 118dB into T1. More than enough to drive both cans with authority. So I agree about people saying "Mojo is not enough" to drive these cans is describing their personal preference with the pairing and not the power output.

 
Some people do listen crazy loud like there's no tomorrow, so we can't assume what's "powerful enough". I'm actually worried about the contrary, where Mojo can blow up headphones if handled incorrectly.
 
One thing I do want to send an alarm bell is that just because an amp is a hefty "desktop" amp doesn't always mean that it has better driving power than a portable gear like the Mojo.
A lot of huge looking amps still cap out at something like +/- 5V peak rail voltage, depending on the design.
 
Some amps (like tube amps) do distort gracefully upon clipping, without adding much edgy harmonics, which people prefer the sound of. As for the Mojo, my brain will probably explode if I push it till it starts showing clipping distortion.
 
Dec 2, 2015 at 2:42 AM Post #6,115 of 42,758
  Two major shops says the Mojo cannot push the HD800 properly. My friend tried it and it couldnt.
 
absolute and complete nonsense....both the hugo and the mojo drive the hd800 beautifully without any issue...and sound terrific


I think we could break it down like this: Mojo is smaller than the headphones. Therefore it must not be able to drive them properly, despite the truth of its output VS a favoured desktop DAC/amp. It is pointless to argue with people that believe in magic.
 
Dec 2, 2015 at 3:48 AM Post #6,116 of 42,758
Mojo can drive the my HD800 fine. It's not even trying hard. But it is not a Ragnarok! And it shouldn't be or else my Rok will be demoted to speaker amp only.
 
Dec 2, 2015 at 5:30 AM Post #6,117 of 42,758
  It can push 5.3V when fully charged.

 
 
I think I measured over 7v, but haven't tried it with Hd-800s. Can anyone confirm?

 
Holy crap !  I read that 4.3v figure in an online review (their test results) and was impressed - but that Rob confirmed 5 is even more mind-blowing.  I am now extremely interested in getting this nugget.  
 
What kind of real-world battery times are people getting ? 
 
Dec 2, 2015 at 5:46 AM Post #6,118 of 42,758
Does anyone know if there any way to get DSD256 to work on Mojo on JRiver Media Center?
 
JRiver seems to have a bug/issue that it only does DSD256 natively (on ASIO etc), whereas DoP (what Mojo needs) caps out at DSD128.
 
I can get DSD256 working with Mojo on Foobar and Audirvana, but just not JRiver.
 
Dec 2, 2015 at 6:44 AM Post #6,120 of 42,758
  I didnt even know DSD256 album existed! 

 
Yeah. It depends on what genre of music you like listening to. Classical listeners have been dealing with DSD files on a daily basis ever since the SACD days.
We are used to spending $50 on physical albums so DSD downloads are no big deal.
There are some great labels like:
http://spiritofturtle.com/product-category/download/
 
DSD256 files started coming out in the last year or so, because studios started installing A/D converters like Merging Horus that records DSD256 natively.
Until then, most studios could only record up to DSD64 or 128 so the DSD256 were just software upscales that were done as a proof of concept.
 
I don't want to get into arguments about the sonic merits etc, but it's worthwhile trying since Mojo supports it natively.
The best thing to do is to listen to what the recording engineer thought was the best format.
 

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