[Fiyero]

Dear all
I don't know if this is the right forum.

I have a Moondrop S8 IEM and I have bought a used Chord Mojo DAC in the last days.

When I connect the IEM to the DAC to the smartphone I hear some noise as an electric interference.

This noise increases when the USB C Plug of the OTG cable gets near the Plug of the smartphone.

The S8 is a 16ohms 122db IEM.

I have not performed other tests with different sources or different IEM or different DAC (in the past I used a Meridian Explorer 2 DAC never with problems but uctually I have it no longer)

Just tested different OTG cables.


Any idea of what it could be?

Thanks,

 

[surfgeorge]

The Chord Mojo is a bit sensitive to radio frequency interference, and even now with Mojo 2 and Poly I can sometimes hear a ticking or clicking noise with sensitive IEMs. The official statement from Rob Watts was that Mojo should only be able to pick up G2 mobile phone communication and that would stop as G2 is phased out. But I can hear it in various situations as well...
It's definitely annoying with sensitive IEMs

Try the following:
Connect the IEM with Mojo, far away from the phone or other sources of RFI.
Is there any noise? If yes, does the noise increase when you increase the volume?

Next, connect the Mojo with a computer via USB cable and check for noise again.

Then try connected to the phone, keeping longer distance between Mojo and phone.

Finally test with the Mojo right next to the phone.

That should give you a better understanding what you are dealing with and what works best.
You can also try to use some clip-on ferrits on the USB cable and see if that makes a difference.

Good luck! Should be a nice pairing otherwise!

 

[Kentajalli]

The Chord Mojo is a bit sensitive to radio frequency interference, and even now with Mojo 2 and Poly I can sometimes hear a ticking or clicking noise with sensitive IEMs. The official statement from Rob Watts was that Mojo should only be able to pick up G2 mobile phone communication and that would stop as G2 is phased out. But I can hear it in various situations as well...
It's definitely annoying with sensitive IEMs

Try the following:
Connect the IEM with Mojo, far away from the phone or other sources of RFI.
Is there any noise? If yes, does the noise increase when you increase the volume?

Next, connect the Mojo with a computer via USB cable and check for noise again.

Then try connected to the phone, keeping longer distance between Mojo and phone.

Finally test with the Mojo right next to the phone.

That should give you a better understanding what you are dealing with and what works best.
You can also try to use some clip-on ferrits on the USB cable and see if that makes a difference.

Good luck! Should be a nice pairing otherwise!

Just to put a fine point on the noise issue:
- All portable Chord DACs are sensitive to ground loop noise.
This is because of two reasons: 1- they do not have galvanic isolation on USB or Coax inputs. They are portable devices, and power drain was decided against. I am not aware of any portable DACs that do have isolation. BTW, Toslink is fine. 2- By default they are single ended.
Use them as portable, don't worry about RFI.
- Mojo in particular (AFAIK) was sensitive Not to RFI, but EMI! that is Electro Magnetic Interference. Do not strap your phones to it! that causes EMI, not to mention ugliness and bulk

 

[goodvibes]

You can always try a thin sheet of mu metal between devices if you're getting EMI.

 

[dakanao]

For me the Moon Audio Black Dragon USB cable and most importantly the iFi iSilencer+ fixed the thinning of the sound caused by the RFI and EMI interference.

 

[Kentajalli]

For me the Moon Audio Black Dragon USB cable and most importantly the iFi iSilencer+ fixed the thinning of the sound caused by the RFI and EMI interference.

For portable use, these are bulky. Cables don't do anything.
Just keep the phone away from Mojo, that fixes EMI.
While in mobile use, there is no RFI, just EMI.
In desktop use, the iSilencer, Topping HS01 and the like are good for USB, OR use Toslink.

 

[Another Audiophile]

Do those interested I have my poly for sale here on head fi

 

[rubymonday]

Having listened to speakers for 50 years I decided to give my wife a break and get some headphones. That lead to a need for something more portable to use with the headphones and I’ve just bought a Mojo2 and Poly. The technology, DACs etc is new to me so my question is probably quite basic.

In configuring the Poly there is an option to select DSD/BIT PERFECT, which sounds like a good thing to have, but I can’t figure out what it does. The Poly manual says that it “disables the physical volume control on the control device”. I thought the control device would be the iPad that I was using to link to Qobuz, but the volume keys on the iPad still control the Mojo2 volume, with the DSD/BIT PERFECT option set on.

I asked Chord Support about this and they said “Bit Perfect turns the Poly volume off”.

I’m none the wiser as I didn’t realise the Poly had a volume control. I like to try and understand how these things work so I would be grateful for any further explanation.

Thanks

 

[jarnopp]

Having listened to speakers for 50 years I decided to give my wife a break and get some headphones. That lead to a need for something more portable to use with the headphones and I’ve just bought a Mojo2 and Poly. The technology, DACs etc is new to me so my question is probably quite basic.

In configuring the Poly there is an option to select DSD/BIT PERFECT, which sounds like a good thing to have, but I can’t figure out what it does. The Poly manual says that it “disables the physical volume control on the control device”. I thought the control device would be the iPad that I was using to link to Qobuz, but the volume keys on the iPad still control the Mojo2 volume, with the DSD/BIT PERFECT option set on.

I asked Chord Support about this and they said “Bit Perfect turns the Poly volume off”.

I’m none the wiser as I didn’t realise the Poly had a volume control. I like to try and understand how these things work so I would be grateful for any further explanation.

Thanks

It depends on your source and how it is set up to accept this command. If you have a physical DAP with a volume control and you select BitPerfect mode, Poly will ignore that and pass the full signal to Mojo. It doesn’t always work, so best to use Mojo’s volume and keep00%, which should be bit perfect.

 

[rubymonday]

Thanks. I set the iPad volume on its highest setting as anything lower wasn't allowing sufficient volume from the Mojo.

 

[peter1808]

Hi, I was just wondering is a used chord mojo still a good purchase today? Also any comparisons to the mojo 2 will be much appreciated since I've heard only the 2's. Thanks!

 

[alekc]

Hi, I was just wondering is a used chord mojo still a good purchase today? Also any comparisons to the mojo 2 will be much appreciated since I've heard only the 2's. Thanks!

@peter1808 Mojo2 is cleaner with more details and a bit more air and wider soundstage yet in default settings it is missing that magical sparkle Mojo 1 has. Default sound signature of Mojo 2 is colder yet it is still musical. Mojo 2 is closer to Hugo 2 and Qutest IMHO in sound signature while Mojo 1 has more of Hugo TT2 tuning. Assuming you prefer more critical listening and value transparancy and details over bit of warmth and enjoyment in listening Mojo 2 is preffered choice, especially if you consider DSP features which can help you bring M2 sound signature closer to M1. The truth is however I keep returning to original Mojo despite the fact I have M2+Poly for traveling and M-Scaler+TT2 as desktop setup.

 

[peter1808]

@peter1808 Mojo2 is cleaner with more details and a bit more air and wider soundstage yet in default settings it is missing that magical sparkle Mojo 1 has. Default sound signature of Mojo 2 is colder yet it is still musical. Mojo 2 is closer to Hugo 2 and Qutest IMHO in sound signature while Mojo 1 has more of Hugo TT2 tuning. Assuming you prefer more critical listening and value transparancy and details over bit of warmth and enjoyment in listening Mojo 2 is preffered choice, especially if you consider DSP features which can help you bring M2 sound signature closer to M1. The truth is however I keep returning to original Mojo despite the fact I have M2+Poly for traveling and M-Scaler+TT2 as desktop setup.

Thanks for sharing your thoughts! I did find the mojo 2 to be quite cold and more on the analytical side when listening, hence the curiosity about mojo 1.. Looks like I'll probably enjoy the mojo 1 then, I love some warmth, naturalness and musicality when enjoying my music and care less for tech's

 

[alekc]

Thanks for sharing your thoughts! I did find the mojo 2 to be quite cold and more on the analytical side when listening, hence the curiosity about mojo 1.. Looks like I'll probably enjoy the mojo 1 then, I love some warmth, naturalness and musicality when enjoying my music and care less for tech's

@peter1808 you are welcome mate On your place I would try to give M2 another go but with different DSP settings to bring sound signature more towards original Mojo. Don't know your use cases, preferences and headphones you would like to use but I think Mojo 1 + AudioQuest NightOwls or NightHawks can be a real treat even today. On the other hand if you can live with volume inbalance (something unknown to @Rob Watts designs including Mojo 1) and like more warmth I would check out ifi micro black label (but not Signature as it is not as warm as previous ifi dacs from micro line were IMHO). You could later add ifi micro iTube2 for example to get some more warmth but than I would consider getting ifi Pro iCan instead probably and upgrade it later with Elite PSU for blacker background and better sound control. Anyway I think both Mojo's are great but if I would get Mojo 2 first I wouldn't probably get TT2 and at the same time I do not see any reason to invest into Hugo 2.

 

[peter1808]

@peter1808 you are welcome mate On your place I would try to give M2 another go but with different DSP settings to bring sound signature more towards original Mojo. Don't know your use cases, preferences and headphones you would like to use but I think Mojo 1 + AudioQuest NightOwls or NightHawks can be a real treat even today. On the other hand if you can live with volume inbalance (something unknown to @Rob Watts designs including Mojo 1) and like more warmth I would check out ifi micro black label (but not Signature as it is not as warm as previous ifi dacs from micro line were IMHO). You could later add ifi micro iTube2 for example to get some more warmth but than I would consider getting ifi Pro iCan instead probably and upgrade it later with Elite PSU for blacker background and better sound control. Anyway I think both Mojo's are great but if I would get Mojo 2 first I wouldn't probably get TT2 and at the same time I do not see any reason to invest into Hugo 2.

Wow thanks for all the recommendations! I'll be sure to keep an eye out for these I think for now I will just go with the mojo 1 since there is a local dealer here selling it at a good price (roughly 160 USD) and then think about upgrades further down the line. So excited to hear the 'magic'/'rose-tinted' sound people claim the mojo 1 to have. Can't wait!