Chord Mojo(1) DAC-amp ☆★►FAQ in 3rd post!◄★☆
Oct 31, 2019 at 1:53 PM Post #39,436 of 42,765
When I stream from my Samsung S9, the light for stream quality shows up as a very blue blue. Bluer than the one shown in the manual for 192kHz. In any case, it cannot be 192 because it is blue whether I stream from Youtube, Spotify, or Qobuz. But Qobuz for sure is 44, so why does it not change to red. When I stream Qobuz on my PC it does change to red. What can this blue mean?
It probably means that the android settings on your phone default to upscale to 192.
 
Oct 31, 2019 at 5:18 PM Post #39,437 of 42,765
So to answer your question, theoretically there is no mechanism for a battery powered source to create noise floor modulation via RF noise, and this has indeed been verified with listening tests comparing optical to USB. Optical of course is the ideal source, as it's impossible to inject currents from the source to the DAC ground plane.

https://www.head-fi.org/threads/watts-up.800264/page-103#post-15248675

Just throwing this out there for you DIY'ers whom are tired of recurring CCK costs or just don't see value in a Poly.

Last post on this thread before going on hiatus till Hugo₃ launch.

Very happy with the outcome of this just completed summer project. I cannot believe the RBCD experience with this source. It's like having a SOTM SMS-200 in a portable form or having a dedicated CD player as a source. Hans B. mentions this solution does compete pound4pound with the SMS-200. Source matters.

Reminder that I'm working within the constraints of being able to fit everything in a running belt (transportable).

I tried to lower the footprint even further with another rPi0 product, but unfortunately did not produce the same sound results. I'll save that and a Lifatec POF for a Mojo₂.

Loving the rPi 3A+ as it's the same size as a regular rPi HAT thus lowering the footprint dramatically without sacrificing processing power so I don't put pressure on the Lifatec glass optical cable as I did with a full-size rPi.

Till Hugo₃....

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Oct 31, 2019 at 8:34 PM Post #39,438 of 42,765
So many acronyms! Hard to know what they mean without lots of research, but I guess that is the techno-speak of the modding crowd so nothing wrong with it of course.
 
Nov 1, 2019 at 1:14 PM Post #39,439 of 42,765
Question: does mojo-poly playing from an sd card has eq functionality on the mobile phone app? thanks in advanced.
 
Nov 1, 2019 at 1:30 PM Post #39,440 of 42,765
Question: does mojo-poly playing from an sd card has eq functionality on the mobile phone app? thanks in advanced.
  • The standard approach is the phone app (GoFigure or whatever) uses Bluetooth low energy to control playlists on the SD card, and the tracks are played directly from the SD card to the Mojo - so no equalisation is possible using this approach
  • I think a few owners do post about streaming using wifi from the SD card, to the phone app, then back to the phone app to Poly and then on to Mojo. I can't remember the exact details, or whether it was fully successful (you are streaming in two directions using wifi, so this is an opportunity for the phone to sometimes pause, and cause gaps in music feedback) or eq was attempted.
You are probably best asking this question again on the poly thread.
 
Nov 3, 2019 at 1:10 PM Post #39,442 of 42,765
I just finished changing my Mojo's battery following the steps in this video. All went well.

Does anyone know if the new battery requires the same ~10 hours of initial charge time that the Mojo did when it was brand new? Presume yes, but I would like to get others' thoughts on this before I begin using the Mojo.
Best to adopt a cautious approach - assume it will take 10 hours, and you will have ensured that your battery is in the best condition.
However if the charging light goes out after only a few hours, you can regard it as a small bonus, and then use your mojo quicker than expected.
 
Nov 3, 2019 at 8:35 PM Post #39,443 of 42,765
Found it!! Here is the link that got me the solution-
https://answers.microsoft.com/en-us...n/5a70718b-7ecf-4547-a64a-22efda8da0c2?auth=1

Here is a screenshot. I had to change the Default format.


Here is Nora Jones- The Nearness of You.
Ultra HD Audio
Track Quality: 24 bit / 192 kHz
Device Capability: 24 bit / 384 kHz
Currently playing at: 24 bit / 192 kHz

Thanks all!!
I actually found the 32 bit setting to sound a bit cleaner than the 24 bit on non-ASIO music, where's the Khz always sounded the most natural if it's the same as the track played. ASIO still sounds clearly the best no single doubt, it's just that when I playback music in foobar with ASIO, and I want to rewind or go forward on a track, there's a second lag before the track actually skips to that point I clicked.

Or when I'm listening to an album and I want to hear every single song, somehow it skips to a random track not in that album, even though I have my settings at Shuffle-Album

It makes me think that even though it's 24 bits, you can actually hear the loss of transparency, even at 24 fixed bits, compared to the fixed 32 bit setting because of the processing Windows does.
 
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Nov 3, 2019 at 9:24 PM Post #39,444 of 42,765
There is no option of selecting 24 or 32 bit if you are using asio output except in case of dsd asio. In dsd asio selecting 32 bit instead of 24 bit gives more space for dsd over pcm, that's it.
 
Nov 4, 2019 at 3:19 AM Post #39,445 of 42,765
There is no option of selecting 24 or 32 bit if you are using asio output except in case of dsd asio. In dsd asio selecting 32 bit instead of 24 bit gives more space for dsd over pcm, that's it.
I was talking about choosing 32 bits in the Windows mixer option as seen in the picture I quoted. Obviously ASIO automatically selects the bitrate and sample rate and sounds the best, but it lags a bit in the way I've described above.
 
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Nov 4, 2019 at 3:28 AM Post #39,446 of 42,765
I was talking about choosing 32 bits in the Windows mixer option as seen in the picture I quoted. Obviously ASIO automatically selects the bitrate and sample rate and sounds the best, but it lags a bit in the way I've described above.
Windows mixer allows only one sampling rate, whatever you set, it will up or down sample to that. Foobar asio is best and uses least resources.
 
Nov 4, 2019 at 3:56 AM Post #39,447 of 42,765
Windows mixer allows only one sampling rate, whatever you set, it will up or down sample to that. Foobar asio is best and uses least resources.
Yes, but you can choose bit depth as well along with the sample rate...

What I'm saying is, if you play music through the Windows mixer, 32 bit always sounds slightly cleaner than the 24 bit setting. So the best option would be to set the sample rate in Windows mixer the same as the files you're playing, and always have the bit depth at 32 bits.
 
Nov 4, 2019 at 4:04 AM Post #39,448 of 42,765
If you select dsd asio in foobar as output, it also plays pcm files. Now since you can select 32bit or 24bit in settings of dsd asio, i tried both. To me 24 bit was warmer. J river on the other hand sends (if i am correct ) maximum supported bits to dac via asio which is 32bits by default. That is the reason i found j river to slightly bright than foobar asio.
 
Nov 7, 2019 at 12:27 PM Post #39,449 of 42,765
I moved from a Motherboard with a DAC-UP port (Gigabyte) to one without and I can definitely hear the difference. Maybe it's placebo.

What do you guys think? Can less noise on the USB make a difference soundwise? I know the answer in general is 'yes' but I thought with the Mojo being battery the USB port feeding it would not be important.
 
Nov 8, 2019 at 5:57 AM Post #39,450 of 42,765
I moved from a Motherboard with a DAC-UP port (Gigabyte) to one without and I can definitely hear the difference. Maybe it's placebo.

What do you guys think? Can less noise on the USB make a difference soundwise? I know the answer in general is 'yes' but I thought with the Mojo being battery the USB port feeding it would not be important.

Yes, using the Mojo on USB, you will need a USB cleaner.

Rob told us that PCs are noisy. The noise travels along the power lines, of the USB music data cable into the analogue parts of the DAC. That causes brightness to the sound.

I put an Audioquest Jitterbug on my Mojo USB, and the effect was immediate.
 
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