Chord Mojo(1) DAC-amp ☆★►FAQ in 3rd post!◄★☆
Feb 12, 2017 at 10:49 AM Post #30,241 of 42,765
  If you want to explore raspberry pi designs, then @Staxton posted several interesting posts nearly a year ago http://www.head-fi.org/t/784602/chord-mojo-dac-amp-faq-in-3rd-post/20775#post_12766174
 
In many respects a Poly with screen, but of course it is much larger, and I expect that the Poly will generate less internal electrical noise as well.
Nevertheless, the performance would probably only be bettered by streamers using bespoke circuit boards, like the Poly of microRendu.

 
Thanks for the link, but it doesn't tell me anything new. I already researched this extensively. I'm not looking for anything portable. The only reason I am interested in the Raspberry Pi is to see whether a budget network player would improve the sound quality of my desktop system.
 
@silvrr was kind enough to lend me some spare Raspberry Pi equipment (arriving tomorrow) so I can see whether it improves the sound in my case. If it does, I'll probably buy one for myself.
 
Either way, I don't plan on upgrading to a better network player until I get the SOtM sMS-200. (Which beat the microRendu and everything else.)
 
Feb 12, 2017 at 11:01 AM Post #30,242 of 42,765
Thanks heaps Rob. What's the formula to work out 1db down = max Vrms ?

Also I've read all the info about the reasons Toslink may have an advantage over the USB and SPDIF coax inputs for the Mojo (like galvanic isolation).

But in terms of the simplest path from input to the Mojo's FPGA, does the Toslink have the most direct path of all the Mojo's inputs, i.e. just wire from the Toslink connector to the FPGA?

Love the technology packed into this little thing. A true classic.

This should help: http://www.head-fi.org/t/784602/chord-mojo-dac-amp-faq-in-3rd-post/25770#post_13008622
 
Feb 12, 2017 at 11:03 AM Post #30,243 of 42,765
How about an old tablet as the interface. Then use a Chromecast audio with Optical out to Mojo, then to AVR or whatever the end component is. That way, you don't tie up your main device (cellphone) and still get a nice interface (and Tidal streaming) via the 2nd tablet.
 
Feb 12, 2017 at 11:13 AM Post #30,244 of 42,765
  How about an old tablet as the interface. Then use a Chromecast audio with Optical out to Mojo, then to AVR or whatever the end component is. That way, you don't tie up your main device (cellphone) and still get a nice interface (and Tidal streaming) via the 2nd tablet.

 
I only use headphones and currently play audio files on my laptop, connected to the Mojo via USB.
 
I do not own tablets or smartphones. I would only be interested in this if someone can confirm it outperforms the sound quality of the Raspberry Pi. (And for all I know, my laptop may sound the same or better than that anyway.)
 
Feb 12, 2017 at 11:41 AM Post #30,245 of 42,765
   
I only use headphones and currently play audio files on my laptop, connected to the Mojo via USB.
 
I do not own tablets or smartphones. I would only be interested in this if someone can confirm it outperforms the sound quality of the Raspberry Pi. (And for all I know, my laptop may sound the same or better than that anyway.)

If you listen to audio via your laptop connected to the Mojo, where does the desktop portion come in? What interface out would you be using in the Raspberry Pi? Would it be the Dac such as a HiFiBerry, or just the interface via WiFi or Lan (network streamer capability) that will then output a digital/optical signal to a different DAC? You'll get higher bitrate via USb from your Mac than Optical out from the Raspberry Pi or Chromecast going optical. In the instance where I mentioned an old tablet (which would theoretically be your Network streamer) to a Chromecast (which would be outputting the Optical Signal to external DAC) to an AVR is the setup I use. The DAC in the AVR is my final link in the chain. I've also done this from the Chromecast to the Schiit Modi2U and then out to my AVR. In the end though, I believe you will get higher quality out of the Pi though. The Chromecast is limited to 24/96 in Optical Out.
 
Feb 12, 2017 at 12:05 PM Post #30,246 of 42,765
  If you listen to audio via your laptop connected to the Mojo, where does the desktop portion come in? What interface out would you be using in the Raspberry Pi? Would it be the Dac such as a HiFiBerry, or just the interface via WiFi or Lan (network streamer capability) that will then output a digital/optical signal to a different DAC? You'll get higher bitrate via USb from your Mac than Optical out from the Raspberry Pi or Chromecast going optical. In the instance where I mentioned an old tablet (which would theoretically be your Network streamer) to a Chromecast (which would be outputting the Optical Signal to external DAC) to an AVR is the setup I use. The DAC in the AVR is my final link in the chain. I've also done this from the Chromecast to the Schiit Modi2U and then out to my AVR. In the end though, I believe you will get higher quality out of the Pi though. The Chromecast is limited to 24/96 in Optical Out.

 
Desktop audio system as in it is literally on a desktop. (And not portable in the pocket sense.)
 
I would connect the Mojo to the Raspberry Pi via USB and stream music to it from my laptop via Ethernet or Wi-Fi.
 
I do not have a Mac; it is an Alienware M11x R2 with Windows 10.
 
Feb 12, 2017 at 12:14 PM Post #30,247 of 42,765
   
Desktop audio system as in it is literally on a desktop. (And not portable in the pocket sense.)
 
I would connect the Mojo to the Raspberry Pi via USB and stream music to it from my laptop via Ethernet or Wi-Fi.
 
I do not have a Mac; it is an Alienware M11x R2 with Windows 10.

Then I will step back and watch intently as you proceed in your search. I too wonder then, using a *NIX variant of the OS on the Pi would give you access to higher than 192Khz bitrate. Nice little laptop by the way. My wife had the R1 when it came out. I pre-ordered it unknowingly. I thought it was already shipping, but we had to wait 3 mos. in order for it to be built and shipped to us. 
 
Feb 12, 2017 at 12:37 PM Post #30,248 of 42,765
  Then I will step back and watch intently as you proceed in your search. I too wonder then, using a *NIX variant of the OS on the Pi would give you access to higher than 192Khz bitrate. Nice little laptop by the way. My wife had the R1 when it came out. I pre-ordered it unknowingly. I thought it was already shipping, but we had to wait 3 mos. in order for it to be built and shipped to us. 

 
Nearly all my files are CD rips, so I don't care about high bit rates. (It can play DSD too, though.)
 
My Alienware was way overpriced. Paid $1,400 for it and it's falling apart after six years. Next serious computer I get will be a custom desktop.
 
Feb 12, 2017 at 12:41 PM Post #30,249 of 42,765
   
Nearly all my files are CD rips, so I don't care about high bit rates. (It can play DSD too, though.)
 
My Alienware was way overpriced. Paid $1,400 for it and it's falling apart after six years. Next serious computer I get will be a custom desktop.

smart move on custom desktop. How do you like the Mojo and Elear pairing. I've not heard good things about Mojo to LCD-XC, so looking at future  upgrade path beyond LCD-2F.
 
Feb 12, 2017 at 1:03 PM Post #30,251 of 42,765
   
Nearly all my files are CD rips, so I don't care about high bit rates. (It can play DSD too, though.)
 
My Alienware was way overpriced. Paid $1,400 for it and it's falling apart after six years. Next serious computer I get will be a custom desktop.

 
I think any laptop will fall apart in a few years (just look at macbook GPU failures). Their design prohibits thorough cleaning of the hardware and will eventually result to overheating, throttling etc. Desktops OTOH are easily maintained, can remove all of the dust lints and never throttle unless you have so many dust blocking the airflow. Unless you game like crazy, even a small Intel NUC suffices.
 
Feb 12, 2017 at 1:09 PM Post #30,252 of 42,765
  I think any laptop will fall apart in a few years (just look at macbook GPU failures). Their design prohibits thorough cleaning of the hardware and will eventually result to overheating, throttling etc. Desktops OTOH are easily maintained, can remove all of the dust lints and never throttle unless you have so many dust blocking the airflow. Unless you game like crazy, even a small Intel NUC suffices.

 
Oh, I meant literally falling apart. The hinges are barely there anymore so I have to rest the screen against something behind it. Some of the keys don't work anymore so I have to use an external keyboard sometimes. And so on. Ironically, I have no fan issues anymore. The fan used to go crazy and it would overheat too easily. Now the fan seems to be broken since I never hear it anymore, yet it rarely overheats. Go figure. As far as performance goes, I'm happy enough with it.
 
Feb 12, 2017 at 1:12 PM Post #30,253 of 42,765
m8o, my previous post was only referring to your comment that you haven't read the whole thread. Besides the line-out information, there is a lot of other interesting information, especially in the 'Informative post by Rob Watts' section.

________________________________________________________________________________


I just tested mine while plugged in to my USB wall charger, battery power/charging indicator on:

- Hold all three buttons to turn on the device. My Mojo is now set to the blue/violet line level of 3Vrms.

- Lowered the volume to double red.

- Turned off the Mojo.

- Hold all three buttons from an off state and again I'm in line level mode.

Sorry, I'm not sure why yours may be different.


I returned to this this morning after it had been off 10hrs and was done charging.

As it is fully charged, I disconnected the charger before performing your test. When I did, it does work as designed. Volume orbs are the 3V violet we expect.

I plugged the charger backin to the Mojo and re-performed the test. It once again returns to red orbs, not the 3V level violet. :/ I did it twice.

Disconnect power and re-re-retest ... and line level is engaged. Volume orbs are violet.

Hopefully is addressed if I update firmware... may instead return it to the vendor I bought it from at CanJam.

Thank again for your time testing yours.
 
Feb 12, 2017 at 1:17 PM Post #30,254 of 42,765
I returned to this this morning after it had been off 10hrs and was done charging.

As it is fully charged, I disconnected the charger before performing your test. When I did, it does work as designed. Volume orbs are the 3V violet we expect.

I plugged the charger backin to the Mojo and re-performed the test. It once again returns to red orbs, not the 3V level violet. :/ I did it twice.

Disconnect power and re-re-retest ... and line level is engaged. Volume orbs are violet.

Hopefully is addressed if I update firmware... may instead return it to the vendor I bought it from at CanJam.

Thank again for your time testing yours.

 
Just tested it while charging. Line level is indeed violet.
 
I guess I had done it the wrong way in the past, because I thought line level was light blue. (The manual says it's supposed to be light blue, but perhaps that's for an old version?)
 
To set the output level to 3V ( line level ) for connection to a preamplifier press both volume buttons together when switching on the unit. Both volume balls will illuminate light blue.

 
Feb 12, 2017 at 1:17 PM Post #30,255 of 42,765
I observed just now that this thread has been going since 2015, has had over 30'000 posts and over 2.5 million views.
Astonishing, especially as I would imagine most urgent questions and quality reviews were all done in the first few months of release!
Quite a testament to the product and Chord's input on here
beerchug.gif

 

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