[rlw6534]

Doesn't the poly have a desktop mode?

I don't really know. The LED does turn purple similar to the Mojo if left plugged in. Perhaps someone that knows better can chime in. I thought that the OP was unplugging at night and wondering why it didn't go back to desktop mode when plugged back in. I may have misunderstood.

 

[Daniel Johnston]

I don't really know. The LED does turn purple similar to the Mojo if left plugged in. Perhaps someone that knows better can chime in. I thought that the OP was unplugging at night and wondering why it didn't go back to desktop mode when plugged back in. I may have misunderstood.

Got it. It sounds like he's leaving it plugged in and it drops out of desktop mode. Sounds like OP needs to clarify.

The constant drain on battery from the Poly hasn't changed. I used to store the mojo and poly separately.

 

[580847]

I just wanted to make people aware that this issue is real and from my point of view, quite dangerous. And to all the happy owners who haven't had the issue, I am jealous!

Thank you for this, ear health is #1 priority over everything else. This gives me PTSD flashbacks of the original Mojo.

That's why I'm content to just go with an USB-C iPhone Dongle for "background noise" use case. It's fine for casual listening because you have factor in Environmental noise pollution and awareness of your surroundings.

My plan is to build my own small footprint DAP with a highly optimised Audiophile OS (need CPU horsepower) that USB-C outs into a USB-C iPhone dongle. I've already got this working on a desktop prototype, but Supply Chains are finally replenishing after 2-3 years so I have hope for 2024 to procure the necessary hardware. I also only Music playback in RAM, so it meets all my requirements. UI is wirelessly controlled by iPhone.

This gives me flexibility if I want to upgrade to a M2 (USB-C) one day if I ever want a "living experience" over "background noise". But I would never consider any other DAC besides iPhone dongle for value and M2 for musicality. But it's true that iPhone dongle gets fatiguing in less than an hour. If a Chord DAC has a proper RF-free chain, it doesn't get fatiguing so +1 ear health points.

 

[Daniel Johnston]

Thank you for this, ear health is #1 priority over everything else. This gives me PTSD flashbacks of the original Mojo.

That's why I'm content to just go with an USB-C iPhone Dongle for "background noise" use case. It's fine for casual listening because you have factor in Environmental noise pollution and awareness of your surroundings.

My plan is to build my own small footprint DAP with a highly optimised Audiophile OS (need CPU horsepower) that USB-C outs into a USB-C iPhone dongle. I've already got this working on a desktop prototype, but Supply Chains are finally replenishing after 2-3 years so I have hope for 2024 to procure the necessary hardware. I also only Music playback in RAM, so it meets all my requirements. UI is wirelessly controlled by iPhone.

This gives me flexibility if I want to upgrade to a M2 (USB-C) one day if I ever want a "living experience" over "background noise". But I would never consider any other DAC besides iPhone dongle for value and M2 for musicality. But it's true that iPhone dongle gets fatiguing in less than an hour. If a Chord DAC has a proper RF-free chain, it doesn't get fatiguing so +1 ear health points.

I applaud the exercise in building technology, but why not buy an iBasso with Mango OS? It meets your criteria you listed. As for background listening, the Denon PerLpro are stunningly good. I nenver cared for the apple dongle, just too fatiguing.

After revisiting Poly, that would meet your criteria as well.

 

[BS5711]

Regarding white noise, I started doubting my recent comment so I dug up my original post as below:

" Another white noise situation since we are comparing notes.

Fiio M11 Plus streaming Tidal through UAPP to Mojo (og) via custom Moon Audio COAXIAL cable, listening most of the day and no problem as usual.

Before packing away for the day I did a quick back and forth with Mojo and iFi Go Bar. Plugged COAXIAL cable back in while UAPP presumably thought it was still connected to Go Bar and white noise.

Actually kind of odd, white noise in the left channel and the song at about 1/4 speed in the right. "


Chord Mojo white noise is not exclusive to USB input.

My recent comment was not a 100% accurate recollection, it was the coaxial cable I was removing and upon abruptly plugging it back in while the source apparently hadn't figured out what it should be outputting a white noise burst resulted.

 

[580847]

USB interface is bad for anything but the most casual gaming due to the buffer causing latency. Not sure how the latency is on optical on the Mojo 2, but Mojo 2 over USB is quite noticeably behind my RME ADI-2 Fs Dac over optical when running both from roon in synced mode from the same PC. If both are on USB then they are similarly delayed.

I game on a realtime low-latency kernel so it balances out by extreme low levels of latency measurements from the start along with the Game running entirely in RAM. I only use USB on PCI-E so it has a direct path to the CPU. Similar to the Apple USB-C cable Youtube Video posted where they mention how a Thunderbolt connection has a PCI-E direct connection to the CPU if using Mac hardware. So I've done all that's humanly possible with Gaming on a Chord DAC. Toslink will just add more cons than pros.

Oh, I don't think I set my USB to high priority yet on the OS so I'll look into...

Not that it matters, but technically it's possible my Chord USB connection is galvanically isolated by powering the USB cable off the grid. I think that can apply to the M2 too. If you power the USB cable off the grid, the M2 is possibly technically galvanically isolated as power and data are separated.

For Music, I want to give USB one more chance before giving up.

So:

1. Unlocked Soundstage qualities in Chord DAC with Toslink by utilising premium clocks as SPDIF requires mandatory clocks. Your can use cheap, generic clocks or superb measuring clocks. In any case, SPDIF needs a clocking mechanism. This is clocking on the source, nothing to do with the Chord DAC. Mutually exclusive.
2. Unlocked Soundstage qualities in Chord DAC with USB optical for Gaming by powering USB optical off the grid. Galvanically isolated?
3. TBD Soundstage qualities with USB 2024 project. If no improvements or it doesn't sound like Toslink, I'll give up on USB. The key is to reduce Noise Floor Modulation and then let the Chord DAC naturally do it's thing and hopefully shine by removing the micro-variances. I didn't think this was possible with USB until last month, but it worked with Gaming so it gives me some hope to at least attempt this since I already have all the sunk costs tools. In any case, I made peace with USB as it unexpectedly substantially improved my Gaming experience. Crossing fingers this can be replicated for Music.

 

[580847]

this sounds good but music sounds better than white noise to me

I don't have any Chord DAC or Audiowise gadget any more but this converter allowed music instead of white noise , so this is important to me

Again mainly an issue at higher sample rates

Yes, I just recently jumped into this thread and figured out later this was mainly an up-sampling not overall architecture issue.

I guess why I responded was I think you can do this with USB now in 2024. No need for optical, then up-sample. That gets messy, your clocking the original Toslink signal, then clock again to the higher BNC signal. I get that Toslink is Chord Reference. I'm very, very pro-toslink that's why I run premium clocks but I think there is a workaround in 2024 to get USB with Toslink decoupling benefits.

If you can replicate the benefits of optical via USB, then you don't need any fancy devices to convert. Let USB do it more natively assuming USB can naturally up-sample with ease while optical needs specific clocks to get to higher sample rates.

I won't know until I implement in 1-2 months, but I'll post a possible USB alternative to Toslink for Chord DACs this month.

 

[580847]

I applaud the exercise in building technology, but why not buy an iBasso with Mango OS? It meets your criteria you listed. As for background listening, the Denon PerLpro are stunningly good. I nenver cared for the apple dongle, just too fatiguing.

After revisiting Poly, that would meet your criteria as well.

I need CPU Power and RAM for my Audiophile OS so only a few devices meet these requirements. I'm good with my Desktop setup for serious listening, so having a portable Chord setup I will just burn out on serious listening. The iPhone dongle is more forgiving on tracks (Casual Listening) while the Desktop setup is ruthless on tracks so mainly for the well-mastered tracks (Serious Listening). It's a balance.

But once I get use to the portable setup, it opens the doors for a future M2 upgrade. I just unplug the Dongle, plug in the M2, config software and wrap with rubber bands together. The iPhone dongle measures flat and does the job. It's not for daily driver use, it's for random one hour use here and there.

For my desktop, I'm running something better than this baseline standard. I run much better clocks, much better passive Off The Grid Power Supplies (No Mains), FPGA brain and better OS which needs CPU Power and RAM:

For my portable small footprint DAP, I want similar qualities as my Desktop without the clocking. Preliminary prototype testing, it works well with the iPhone Dongle for one-hour uses before fatigue kicks in.. but this is over Mains not Battery yet so fatigue time unknown.

It's almost 2024, so there have been significant advances in CPU Power for these small devices. I want that CPU Power to process my Music. I guess it can easily do that Mumbo Jumbo software upsampling thingy on the go, but running the wrong algorithm is against policy.

 

[flyte3333]

As much as I like to support a Canadian product, its not the Audiowise that solves the issue.

Upsampling to PCM 705.6khz fixes it. For Chord dacs I had the Mojo and now the Mojo 2 both had that issue with USB, I suppose Chord Dacs just have very sensitive USB interface.

The Mojo 2 is definitely a great sounding DAC tho.

it doesn't solve the issue at all. Lots of people of Roon forum report this too. Roon can upsample

 

[Daniel Johnston]

Regarding white noise, I started doubting my recent comment so I dug up my original post as below:

" Another white noise situation since we are comparing notes.

Fiio M11 Plus streaming Tidal through UAPP to Mojo (og) via custom Moon Audio COAXIAL cable, listening most of the day and no problem as usual.

Before packing away for the day I did a quick back and forth with Mojo and iFi Go Bar. Plugged COAXIAL cable back in while UAPP presumably thought it was still connected to Go Bar and white noise.

Actually kind of odd, white noise in the left channel and the song at about 1/4 speed in the right. "


Chord Mojo white noise is not exclusive to USB input.

My recent comment was not a 100% accurate recollection, it was the coaxial cable I was removing and upon abruptly plugging it back in while the source apparently hadn't figured out what it should be outputting a white noise burst resulted.

It would make sense if you were "rapidly" unplugging and plugging in the coax cable to get a glitch. It's not confirmed that the "bug" or whatever is due to the USB chip. It could be very well due to the FGPA for all we know.

 

[Cam9102]

The more the white noise issue gets discussed, makes me feel that it’s not exactly fit for purpose of being a portable device. I’m in a situation where I bought the Mojo 2 and returned it due to the white noise issue however as others have said it’s not just a Chord problem. I wanted to go down the portable dac/amp route however it might just be better to get another DAP but with that is the old OS issue and app support

 

[Daniel Johnston]

The more the white noise issue gets discussed, makes me feel that it’s not exactly fit for purpose of being a portable device. I’m in a situation where I bought the Mojo 2 and returned it due to the white noise issue however as others have said it’s not just a Chord problem. I wanted to go down the portable dac/amp route however it might just be better to get another DAP but with that is the old OS issue and app support

Portable is a broad category. The Mojo2 is portable, but I personally wouldn't use it commuting on a subway. A set of TWS buds like the Denon PerL give amazing sound and are easily portable. The Sony NW-A306 is tiny, powerful, and sounds great. I have a Shanling M0 pro that is crazy good and stable. If the device is using a standard DS chipset (AKM, ESS, ROHM, etc...) white noise will be highly unlikely.

IBasso.with the mangoOS/android dual boot gives you the best of both worlds between using popular streaming apps and a stable audio optimized OS.

The noise isssue is disproportionately expressed on forums like this. Your opinion will be skewed reading these forums. I still maintain that if you buy another Mojo2, you likely will not have an issue. I would say 0% chance of a repeat, but clearly others had different experiences than me. Maybe my opinion has been skewed by reading these forums.

 

[evhvis]

I game on a realtime low-latency kernel so it balances out by extreme low levels of latency measurements from the start along with the Game running entirely in RAM. I only use USB on PCI-E so it has a direct path to the CPU. Similar to the Apple USB-C cable Youtube Video posted where they mention how a Thunderbolt connection has a PCI-E direct connection to the CPU if using Mac hardware. So I've done all that's humanly possible with Gaming on a Chord DAC. Toslink will just add more cons than pros.

Oh, I don't think I set my USB to high priority yet on the OS so I'll look into...

Not that it matters, but technically it's possible my Chord USB connection is galvanically isolated by powering the USB cable off the grid. I think that can apply to the M2 too. If you power the USB cable off the grid, the M2 is possibly technically galvanically isolated as power and data are separated.

There is a buffer on USB and it is an asynchronous transfer technology, which is what creates the latency. Direct path to CPU etc. doesn't mean much as the USB latency itself is minimal, it is the buffering on both sides that are the main bottleneck. If you have 1024 samples of buffer then you have aprox. 20ms of lag just on the transmitting end. Then add long filters in the Chord DAC etc. and you get quite a bit of latency.

In a low latency game on a low latency system the delay is typically 20-30ms from peripheral to on-screen action. Low latency monitors are typically 3-7ms of latency while "normal" monitors will typically have 15-30ms of latency. The delay on the mojo makes the sound noticeably out of sync so I wouldn't use it over USB for any kind of fast paced gaming. It is fine for slower more casual gaming where timing isn't that important.

You can still get ground plane interference as there is still a reference ground between the units, your ground is just floating. Only way to have proper galvanic isolation is to use something like an Intona or similar device or to have galvanic isolation in the USB port of the DAC (not feasible on a unit that must work from phones due to powerdraw).

 

[dericchan1]

There is a buffer on USB and it is an asynchronous transfer technology, which is what creates the latency. Direct path to CPU etc. doesn't mean much as the USB latency itself is minimal, it is the buffering on both sides that are the main bottleneck. If you have 1024 samples of buffer then you have aprox. 20ms of lag just on the transmitting end. Then add long filters in the Chord DAC etc. and you get quite a bit of latency.

In a low latency game on a low latency system the delay is typically 20-30ms from peripheral to on-screen action. Low latency monitors are typically 3-7ms of latency while "normal" monitors will typically have 15-30ms of latency. The delay on the mojo makes the sound noticeably out of sync so I wouldn't use it over USB for any kind of fast paced gaming. It is fine for slower more casual gaming where timing isn't that important.

You can still get ground plane interference as there is still a reference ground between the units, your ground is just floating. Only way to have proper galvanic isolation is to use something like an Intona or similar device or to have galvanic isolation in the USB port of the DAC (not feasible on a unit that must work from phones due to powerdraw).

I don't game but I wonder if adding an intona in betweeen, while providing galvanic isolation, will in fact adding to the latency...?

 

[evhvis]

I don't game but I wonder if adding an intona in betweeen, while providing galvanic isolation, will in fact adding to the latency...?

USB is a real-time protocol so it wouldn't work properly if it caused major latency. Doesn't make much difference if there is an intona inbetween or not, USB on both RME and Mojo 2 is still way behind optical into RME.