[DjBobby]

All tracks played with Tidal in MacOS are played to Mojo as 16/44.1 (red ball) independently if the are hi-res.
Is there any configuration I can make in audio settings in MacOS yo fix this?

Getting 96khz with all master tracks played through the Mojo. Did you check in the settings-streaming quality-master?

 

[almarti]

Getting 96khz with all master tracks played through the Mojo. Did you check in the settings-streaming quality-master?

Yes I did, I Will try again

 

[474194]

Did you have different ear/headphones when you had the Mojo a few years ago, when you found it warmer?

No, I had the same. My sample size was small tho because I was just getting my feet wet back into the hobby (cold turkey hiatus from 2005-2017). During 2017, I can feel the Mojo warmness in my bones and that's something I remember clearly to compare against. The Mojo was just a gateway experiment into the Chord sound before deciding to jump to the Hugo2. I didn't experiment much with the Mojo as I assumed the warmness was a given, especially since the device is sensitive to it's environment.

2017 Setup:

Digital Source	Cable	Headphone
iPhone CCK w/ Curious USB cable [Maybe Warmness due to USB noise floor and/or RF Noise] -> Mojo [Notoriously Warm, but Measures Flat]	PWAudio 2-wire [Notoriously Warm]	UE-10 [Neutral]
iPhone CCK w/ Curious USB cable [Maybe Warmness due to USB noise floor and/or RF Noise] -> Mojo [Notoriously Warm, but Measures Flat]	PWAudio 2-wire [Notoriously Warm]	UE PRO 18+ [Light Warm]

Experienced warmness on both setups, but again sample size low.

Present Day:

Digital Source	Cable	Headphone
Raspberry Pi w/ WM8804 SPDIF board [Zero noise floor and Zero RF Noise] -> Mojo [Notoriously Warm, but Measures Flat]	SilverFi R1 [Neutral]	UE-10 [Neutral]
Raspberry Pi w/ WM8804 SPDIF board [Zero noise floor and Zero RF Noise] -> Mojo [Notoriously Warm, but Measures Flat]	SilverFi R1 [Neutral]	UE PRO 18+ [Light Warm]

Because the Mojo measures flat, it makes sense a neutral source w/ glass optical that lifts the veil + neutral cable + neutral CIEM should === neutral. But because Mojo is notoriously warm, I didn't think it was possible for the first setup. I'm trying hard to listen for warmness, but it's just not there IMO.

I have not tested the second present day setup yet.

Because I am using a Music streamer, it has the same effect as it does in the Summit-Fi setups. It makes a big time difference especially the PrAT which paces the music beautifully. It has a similar effect to adding a Mscaler. In the Summit-Fi threads, adding a improved digital source (Music streamer) scales the Chord devices. For everyman Chord devices such as Hugo2 and Mojo, it also scales the devices to amazing levels. I can not listen now without a proper digital source. I don't need a $10,000 Music Streamer either. This is more optimal as it's battery-powered and zero USB anything contaminating the sound purity. Everything runs from CPU via the i2s audio bus. The high-end Music streamers usually require mains and USB, but the underlying streaming software is the same. Only thing going for the higher-end Music streamers are they are more powerful (CPU) and the developer optimises the OS, but unless you are running HQPlayer that power is not really needed. Fortunately there are optimised audiophile OS for free so levels the playing field with high-end Music streamers.

I think each of these parts from digital source to neutral headphones plays a role on this potential neutrality. There are very few solid neutral CIEMs and zero truly neutral headphones available (each manufacturer adds it's own color or flavoring) and very few use music streamers with glass optical so it maybe hard to replicate.

IMO:

Digital Source	Cable	Headphone	Opinion
Neutral	Neutral	Neutral	Optimal
Neutral	Warm	Neutral	Good, Can be Great
Neutral	Neutral	Warm	Good, Can be Great
Neutral	Warm	Warm	Too Warm
Warm	Neutral	Neutral	Good, Can be Great
Warm	Neutral	Warm	Too Warm
Warm	Warm	Neutral	Too Warm
Warm	Warm	Warm	War(m) Crime

Digital Source	Cable	Headphone	Amp	Opinion
Warm	Warm	Warm	Warm	This really tilts me when people do this...

 

[calbu]

For people who don't hear the 3-D sound of Mojo using USB (probably due to RFI) and don't want to spend unnecessarily, please try this cheap and reversible experiment:
Materials required:
- Your existing USB cable (use an OTG cable if your source is a mobile to avoid interconnects).
- A roll of aluminum tape like https://www.amazon.com/Sliver-Aluminum-Reflectix-Perfect-Patching/dp/B07S72XQQ1/ref=sr_1_1?keywords=Sliver+Aluminum+Foil+Tape+for+Duct+Work,+1+in+x+66+ft+(4+mil)&qid=1580370244&sr=8-1

- 2 clip-on ferrites that fit your USB cable like https://www.amazon.com/Ferrite-Noise-Filter-Cable-3-5mm/dp/B01N0AV746/ref=sr_1_1?keywords=20+Pcs+Snap+on+Ferrite+Core+Cord+Ring+RFI+EMI+Noise+Filter+Suppressor+Cable+Clip+for+3.5mm/5mm/7mm/9mm/13mm+Diameter+Cable,+Black&qid=1580370520&sr=8-1

Procedure:
1. Attach one clip-on ferrite at each end of the USB cable about 0.5 inch after the connector to allow flexibility.
2. Wrap the whole cable in aluminum tape ensuring that the tape does NOT come in contact with the metal of the connectors. Do not leave even hairline gaps or holes

.



Apologies for the quality of the images.

BTW I discovered this to be only way that worked for me. I tried doubly shielded cables, iFi iSilencer3.0 (similar to AudioQuest Jitterbug), etc. The lack of depth, muddiness, lack of instrument separation and piercing highs disappeared after implementing the solution above.

In my continued attempts to get the best from the Mojo, I discovered that the Mojo chassis is also vulnerable to RFI/EMI. To overcome the RFI/EMI, I put the Mojo in a metal coated plastic pouch used to pack food, with holes for my headphone and USB cables.
Warning : even though Mojo has thermal protection, I don't know the long term impact on the battery.

 

[dakanao]

In my continued attempts to get the best from the Mojo, I discovered that the Mojo chassis is also vulnerable to RFI/EMI. To overcome the RFI/EMI, I put the Mojo in a metal coated plastic pouch used to pack food, with holes for my headphone and USB cables.
Warning : even though Mojo has thermal protection, I don't know the long term impact on the battery.

What kind of double shielded USB cables have you tried out?

 

[GreenBow]

If you're getting RFI in your Mojo, it might be worth looking at a Jitterbug if used from USB.

 

[calbu]

What kind of double shielded USB cables have you tried out?

I don't remember the name of the cable or store I bought it from. One of the shielded cable I tried was this:
https://www.amazon.in/Tiegem-Connector-Charging-480mbps-MicroUSB-TGM5-Black-2m/dp/B07F1VT7XC

I finally settled on this cable because of OTG and length :
https://www.amazon.in/gp/product/B01M5GZ3N0

 

[calbu]

If you're getting RFI in your Mojo, it might be worth looking at a Jitterbug if used from USB.

I tried iFi iSilencer 3.0 (similar to Jitterbug) and it did not work.

 

[miketlse]

I tried iFi iSilencer 3.0 (similar to Jitterbug) and it did not work.

What type of RFI issues are you experiencing?
Are they related to 2G phone networks?

 

[calbu]

What type of RFI issues are you experiencing?
Are they related to 2G phone networks?

Not sure it's only 2G; had some problems with some channels of wifi too. I think 3G (HSDPA) affects too.

The RFI issues I have are screeching highs, lack of depth and grainy sound. Without my cheap RFI shields, the Mojo is virtually indistinguishable from a cheap DAC.

 

[surfgeorge]

I am also puzzled by this. The iPhone results I work from is 3uV noise - which is the same as Mojo - the design brief for Mojo was same noise (in uV) as an iPhone. The recent review on these pages pointed to a dynamic range of 106 dB for the iPhone 6 - and at 1v RMS output, that points to 5 uV of noise - actually worse than Mojo's 3uV.
So hiss on a very sensitive IEM with Mojo should be the same as an IPhone or actually quieter, but with the added plus of 5 times more output voltage too.

Rob

Dear @Rob Watts
I have been enjoying the Mojo for 2 years and absolutely love it. For the longest time I sued it with micro-USB input and it had a dead silent, black backgound.
But after reading about the 3,5mm coax input being superior, and with my improved IEMs actually hearing the better, deeper staging very clearly, I have switched to using th coax input instead of the micro-USB, and there is a weird hiss.

When I power up the Mojo, even without ANY source connected and with no other device next to it, I can clearly hear a quiet hiss.
(The iPhone is dead quiet with the same IEMs)
If I connect the Mojo to my source with the micro-USB cable the hiss immediately disappears, even if the source is OFF.

But there's another strange thing - while I am writing this email, I have the Mojo on and after more than 10 minutes, the hiss disappears for a few seconds, the reappears, after 15 minutes it disappears for a longer time (1-2 minutes) then hisses for a few seconds, then disappears again.
Now, 15 minutes after I switched it on, the hiss seems to be gone. Always without any source connected. And now I can connect my source and listen with dead quiet, black background.
(I had observed this behavior that the hiss goes away after some time but have never before checked the time, so there's no knowing if the 15 minutes are repeatable)

Any idea what could be behind this?
Could it be time to change the battery?

 

[GreenBow]

@surfgeorge I thought it was optical that is the reference sound, since it does not have any RFI noise.

 

[surfgeorge]

@surfgeorge I thought it was optical that is the reference sound, since it does not have any RFI noise.

The thing is, the hiss is there without anything connected to either input. It is real and clearly audible. But I can‘t find an explanation. Must come from Mojo itself

 

[Rob Watts]

Dear @Rob Watts
I have been enjoying the Mojo for 2 years and absolutely love it. For the longest time I sued it with micro-USB input and it had a dead silent, black backgound.
But after reading about the 3,5mm coax input being superior, and with my improved IEMs actually hearing the better, deeper staging very clearly, I have switched to using th coax input instead of the micro-USB, and there is a weird hiss.

When I power up the Mojo, even without ANY source connected and with no other device next to it, I can clearly hear a quiet hiss.
(The iPhone is dead quiet with the same IEMs)
If I connect the Mojo to my source with the micro-USB cable the hiss immediately disappears, even if the source is OFF.

But there's another strange thing - while I am writing this email, I have the Mojo on and after more than 10 minutes, the hiss disappears for a few seconds, the reappears, after 15 minutes it disappears for a longer time (1-2 minutes) then hisses for a few seconds, then disappears again.
Now, 15 minutes after I switched it on, the hiss seems to be gone. Always without any source connected. And now I can connect my source and listen with dead quiet, black background.
(I had observed this behavior that the hiss goes away after some time but have never before checked the time, so there's no knowing if the 15 minutes are repeatable)

Any idea what could be behind this?
Could it be time to change the battery?

The only possibility I can think of is that one of the regulators are in PFD mode and this can increase the noise floor at 4-7kHz by a few dB. By using USB the decoder device will draw more power pushing the regulator out of PFD mode, and eliminating the extra noise.

That said, I would definitely not use coax over USB - USB has ferrites on the ground, but coax does not as ferrites interferes with the SPDIF interface device. So coax will sound brighter than USB, but the brightness is not real improved transparency but more noise floor modulation. So stick with USB!

So I can see people saying what about the coax inputs when using an M scaler? That's different, as the grounds are isolated via the M scaler's galvanic isolation, so coax is not at a disadvantage compared to USB in that case.

 

[surfgeorge]

The only possibility I can think of is that one of the regulators are in PFD mode and this can increase the noise floor at 4-7kHz by a few dB. By using USB the decoder device will draw more power pushing the regulator out of PFD mode, and eliminating the extra noise.

That said, I would definitely not use coax over USB - USB has ferrites on the ground, but coax does not as ferrites interferes with the SPDIF interface device. So coax will sound brighter than USB, but the brightness is not real improved transparency but more noise floor modulation. So stick with USB!

So I can see people saying what about the coax inputs when using an M scaler? That's different, as the grounds are isolated via the M scaler's galvanic isolation, so coax is not at a disadvantage compared to USB in that case.

Thanks a lot for the comprehensive answer!
That definitely solves the problem for me. I was under the impression that it was the USB input that had more noise floor modulation, that's why I switched from USB to Coax.
USB has always worked without any hiss, so I'll just go back to it.

The only disadvantage I see is the mechanically fragile connector, but it has held up with careful use.

And once again - great job on the Mojo and thanks for taking the time to reply here!