Chord Mojo DAC-amp ☆★►FAQ in 3rd post!◄★☆
post-12096756
Post #5,581 of 40,445

audionewbi

Headphoneus Supremus
Joined
Jan 24, 2010
Messages
8,707
Reaction score
2,455
Joined
Jan 24, 2010
Posts
8,707
Likes
2,455
Some of the comments in here honestly makes me want to get a hold of a second mojo so I can compare it with my unit. I have no of the problem you guys face, nor I find Mojo resolving or too resolving. I only get hiss with ck100pro and that is only when I listen at high volumes, at low volumes with music on I hear no hiss. 
 
     Share This Post       
post-12096757
Post #5,582 of 40,445

Ivabign

Headphoneus Supremus
Joined
Jan 16, 2012
Messages
2,917
Reaction score
453
Joined
Jan 16, 2012
Posts
2,917
Likes
453
Are we absolutely sure that the hiss heard isn't the blood flow through the ears vessels?

I am a real OCD character when it comes to noise, was one of the first to declare hiss on the Hugo (much to people's derision) I also declared it on the ZX2, but with the mojo whilst I do pick up a noise when plugging my Layla's into my ears, I think that is now more to do with occlusion than anything else, as is easy to replicate without the mojo at hand...

What are the ohm and efficiency ratings of affected IEMs?

Oh, and going back to cable RFI / EMI, yes, that is one definite thing that does affect Layla and mojo performance, the bass adjuster module sucks up noise like a vacuum sucks up dust...

No, it was determined that my unit suffered from a known issue - it was returned and swapped for a new one.
 
EDIT: My unit had more than a hiss - it was a hum with interesting characteristics.... I detailed it in earlier posts.
 
     Share This Post       
post-12096764
Post #5,583 of 40,445

prismstorm

100+ Head-Fier
Joined
Oct 10, 2015
Messages
390
Reaction score
119
Location
Hong Kong
Joined
Oct 10, 2015
Location
Hong Kong
Posts
390
Likes
119
Website
accessibleaudio.co
So I connected the Mojo to my iMac this morning and the power button is constantly purple (indicating 192/384kHz according to the packaging box and the manual) no matter what sample rate I play. It is simply stuck at purple forever regardless of the variance in different sample rates being played. Is this normal (it will only show purple when connected via USB to a computer) or is my unit faulty?
 
Also, I plugged the 3.5mm TRS of my 7 year old Harmon Kardon Soundsticks into Mojo and it plays just fine, but am I not supposed to do that (Mojo only meant to drive iems or headphones and not speakers of any kind regardless of price and tier).
 
The sound so far seems quite clear, resolving, detailed but is a tad bright for me, will burn-in help or should I change to black filters on my SE846 to tame the treble?
 
     Share This Post       
post-12096769
Post #5,584 of 40,445

Ivabign

Headphoneus Supremus
Joined
Jan 16, 2012
Messages
2,917
Reaction score
453
Joined
Jan 16, 2012
Posts
2,917
Likes
453
  So I connected the Mojo to my iMac this morning and the power button is constantly purple (indicating 192/384kHz according to the packaging box and the manual) no matter what sample rate I play. It is simply stuck at purple forever regardless of the variance in different sample rates being played. Is this normal (it will only show purple when connected via USB to a computer) or is my unit faulty?
 
Also, I plugged the 3.5mm TRS of my 7 year old Harmon Kardon Soundsticks into Mojo and it plays just fine, but am I not supposed to do that (Mojo only meant to drive iems or headphones and not speakers of any kind regardless of price and tier).
 
The sound so far seems quite clear, resolving, detailed but is a tad bright for me, will burn-in help or should I change to black filters on my SE846 to tame the treble?

What program are you using - iTunes? If so, the Mojo will display whatever the max frequency you picked in the MIDI program - it won't change with the individual tune....
 
     Share This Post       
post-12096774
Post #5,585 of 40,445

glider

New Head-Fier
Joined
Feb 8, 2009
Messages
7
Reaction score
16
Joined
Feb 8, 2009
Posts
7
Likes
16
I actually changed to the black filters on my SE846s and preferred those with the Mojo (at least so far). I'll probably swap back and forth to compare some more, but I preferred the slightly more relaxed sound of Mojo + black filters. 
 
     Share This Post       
post-12096779
Post #5,586 of 40,445

Torq

Headphoneus Supremus
Joined
Sep 2, 2015
Messages
1,850
Reaction score
2,111
Location
Seattle, WA
Joined
Sep 2, 2015
Location
Seattle, WA
Posts
1,850
Likes
2,111
Are we absolutely sure that the hiss heard isn't the blood flow through the ears vessels?

I am a real OCD character when it comes to noise, was one of the first to declare hiss on the Hugo (much to people's derision) I also declared it on the ZX2, but with the mojo whilst I do pick up a noise when plugging my Layla's into my ears, I think that is now more to do with occlusion than anything else, as is easy to replicate without the mojo at hand...

What are the ohm and efficiency ratings of affected IEMs?

Oh, and going back to cable RFI / EMI, yes, that is one definite thing that does affect Layla and mojo performance, the bass adjuster module sucks up noise like a vacuum sucks up dust...

100% sure ... otherwise the hiss would be heard with the Mojo switched off as well.

The SE846 are 9 ohms, 114 dB SPL/mw.

It's not something I consider to be a problem. Someone asked if the Mojo was silent with the SE846, mine isn't. That there is very low level audible noise doesn't mean it's intrusive. It's incredibly quiet ... certainly not audible over the quietest musical passages ... but if there's a silent pause then it's there even if it's barely audible.

I'm not trying to troubleshoot it as it's not a problem. If I thought it was, I'd return it.
 
     Share This Post       
post-12096780
Post #5,587 of 40,445

headwhacker

Headphoneus Supremus
Joined
Sep 4, 2013
Messages
4,763
Reaction score
752
Joined
Sep 4, 2013
Posts
4,763
Likes
752
  So I connected the Mojo to my iMac this morning and the power button is constantly purple (indicating 192/384kHz according to the packaging box and the manual) no matter what sample rate I play. It is simply stuck at purple forever regardless of the variance in different sample rates being played. Is this normal (it will only show purple when connected via USB to a computer) or is my unit faulty?
 
Also, I plugged the 3.5mm TRS of my 7 year old Harmon Kardon Soundsticks into Mojo and it plays just fine, but am I not supposed to do that (Mojo only meant to drive iems or headphones and not speakers of any kind regardless of price and tier).
 
The sound so far seems quite clear, resolving, detailed but is a tad bright for me, will burn-in help or should I change to black filters on my SE846 to tame the treble?
 
Check the global sample rate from the Audio Midi Setup. It must be set at 192khz.
 
     Share This Post       
post-12096787
Post #5,588 of 40,445

headwhacker

Headphoneus Supremus
Joined
Sep 4, 2013
Messages
4,763
Reaction score
752
Joined
Sep 4, 2013
Posts
4,763
Likes
752
100% sure ... otherwise the hiss would be heard with the Mojo switched off as well.

The SE846 are 9 ohms, 114 dB SPL/mw.

It's not something I consider to be a problem. Someone asked if the Mojo was silent with the SE846, mine isn't. That there is very low level audible noise doesn't mean it's intrusive. It's incredibly quiet ... certainly not audible over the quietest musical passages ... but if there's a silent pause then it's there even if it's barely audible.

I'm not trying to troubleshoot it as it's not a problem. If I thought it was, I'd return it.
 
The question is  it on the recording or the Mojo itself? It's a problem with mojo if the hiss is present and no music is playing.
 
     Share This Post       
post-12096792
Post #5,589 of 40,445

Torq

Headphoneus Supremus
Joined
Sep 2, 2015
Messages
1,850
Reaction score
2,111
Location
Seattle, WA
Joined
Sep 2, 2015
Location
Seattle, WA
Posts
1,850
Likes
2,111
Some of the comments in here honestly makes me want to get a hold of a second mojo so I can compare it with my unit. I have no of the problem you guys face, nor I find Mojo resolving or too resolving. I only get hiss with ck100pro and that is only when I listen at high volumes, at low volumes with music on I hear no hiss. 

The CK100 pro is 39 ohms and 109 dB SPL/mw sensitivity, so they'd need almost twice the signal, after allowing for the impedance delta, to register a noise that would be audible on the SE846.

Interestingly, if you put the SE846 attenuator inline then the hiss vanishes (impedance change).
 
     Share This Post       
post-12096796
Post #5,590 of 40,445

shigzeo

The Hiss King
Joined
Aug 9, 2006
Messages
12,931
Reaction score
1,056
Joined
Aug 9, 2006
Posts
12,931
Likes
1,056
Website
ohm-image.net
The CK100 pro is 39 ohms and 109 dB SPL/mw sensitivity, so they'd need almost twice the signal, after allowing for the impedance delta, to register a noise that would be audible on the SE846.

Interestingly, if you put the SE846 attenuator inline then the hiss vanishes (impedance change).

The ATH-CK10 is 55Ω @107dB SPL/mw and it is pretty sensitive to hiss. I think people that are not sensitive to hiss are not sensitive to hiss. And there there are people like me. 
 
     Share This Post       
post-12096797
Post #5,591 of 40,445

Torq

Headphoneus Supremus
Joined
Sep 2, 2015
Messages
1,850
Reaction score
2,111
Location
Seattle, WA
Joined
Sep 2, 2015
Location
Seattle, WA
Posts
1,850
Likes
2,111
The question is  it on the recording or the Mojo itself? It's a problem with mojo if the hiss is present and no music is playing.

It's audible with no source connected, with a source connected but not playing, when playing a silent .WAV file.

I don't think it's a "problem" with the Mojo at all. There's no such thing as a noiseless electronic circuit. It's barely audible with the most sensitive IEMs I have. BARELY. But barely isn't silent.
 
     Share This Post       
post-12096798
Post #5,592 of 40,445

shigzeo

The Hiss King
Joined
Aug 9, 2006
Messages
12,931
Reaction score
1,056
Joined
Aug 9, 2006
Posts
12,931
Likes
1,056
Website
ohm-image.net
   
The question is  it on the recording or the Mojo itself? It's a problem with mojo if the hiss is present and no music is playing.

No: lots of DACs/amps/players hiss with no music playing. Some turn their amp section off prior to playing music, and appear to be dead silent. They may then show hiss on paused signals. Hiss is present on ALL sources, it's just a matter of having a sensitive enough piece of equipment to register that hiss. All Mojos will hiss. There may be a minimum level of it we may expect, and beyond that, some defective units, but hiss is completely normal. But sometimes, that hiss is much, much lower.
 
     Share This Post       
post-12096843
Post #5,593 of 40,445

headwhacker

Headphoneus Supremus
Joined
Sep 4, 2013
Messages
4,763
Reaction score
752
Joined
Sep 4, 2013
Posts
4,763
Likes
752
 
No: lots of DACs/amps/players hiss with no music playing. Some turn their amp section off prior to playing music, and appear to be dead silent. They may then show hiss on paused signals. Hiss is present on ALL sources, it's just a matter of having a sensitive enough piece of equipment to register that hiss. All Mojos will hiss. There may be a minimum level of it we may expect, and beyond that, some defective units, but hiss is completely normal. But sometimes, that hiss is much, much lower.
 
I expect at minimum level the hiss should not be audible.
 
     Share This Post       
post-12096863
Post #5,594 of 40,445

shigzeo

The Hiss King
Joined
Aug 9, 2006
Messages
12,931
Reaction score
1,056
Joined
Aug 9, 2006
Posts
12,931
Likes
1,056
Website
ohm-image.net
   
I expect at minimum level the hiss should not be audible.

I have no idea if the unit I borrowed had all its stones in a row or not. But it hissed at minimum levels of volume. It hissed on a level, or slightly more, than an original AK100. Manageable, but too much for me. Still, everything else is phenomenal.
 
     Share This Post       
post-12096868
Post #5,595 of 40,445

audionewbi

Headphoneus Supremus
Joined
Jan 24, 2010
Messages
8,707
Reaction score
2,455
Joined
Jan 24, 2010
Posts
8,707
Likes
2,455
Here is my luck, I have no problem with hissing (not that major) but the sound is still not quiet there. It is a power monster and in its size it is very impressive. I am keeping it purely for that.
 
My aim is to eventually stack it with A17 Walkman once the dongle come out. For me it is not quiet the end it all product. 
 
     Share This Post       

Users Who Are Viewing This Thread (Users: 1, Guests: 17)

  • Top