[SomeGuyDude]

1. Get a better phone with low external magnetic fields.
2. Use a case that has mild steel plates on the surface between Mojo and the phone.
3. Keep the mobile some distance away from Mojo.

Note that this issue is not just a Chord issue, as this noise affects other DAC amps too. Note too that it's not an issue with all phones - I have personally never ever heard RFI on Mojo or Hugo 2.

Yeah you're right. My LG G6, v30, and Note 8 are cheap-ass phones. I'll be sure to upgrade.

I like suggestion #3, too. "Oh hey, you know this device we made for you to use with your mobile device? Keep it away from your mobile device!"

I'm using my Mojo right now, I love the thing, but WOW y'all...

 

[x RELIC x]

Still “breaking in”’ the mojo, adding 4/5 hours overall with it.

I still think that is not “filling” and driving my Hd650 as my old E1 does but I also admit that it could be more distortion on the E1 rather than real driving abilities. I don’t know also because I am dedicating to the Mojo alone for now without other A/B testing.

Still trying it.

My thoughts are that you’ll either like the Mojo with the HD650 or not after some time listening to it. The HD650 does have some bass roll off from 80Hz and downward so maybe the Mojo’s synergy (or lack of) with the HD650 just isn’t for you. Nothing wrong with that. The Mojo doesn’t really burn-in so unless you’ve acclimated to the sound you may want to either seek a source that meets your preferences better with the HD650, or purchase different headphones if you like the Mojo. Mathematically the power (Voltage and Current) is plenty for the HD650.

On a side note, I think it’s good that you are listening to one device for a period of time before going back to the old device as I found this way to be more revealing of characteristic differences than a/b testing. YMMV.

 

[RiseFall123]

Still listening, still on the first charge after out of the box.

My thoughts are: everything is fine, fluid, articulate, detailed, tight and the soundstage is not narrow (as someone said here) and it's big in horizonal and in vertical way. I still hear the highs roll off yet.

I dont have any interference noise issue at all even stick to the phone (4g on).

But it still lacks of impact according to me and the post above me it's probably saying that technically.

I didn't make other A/B test with my Asus E1, but in my memory, there are parts in the songs when the dynamic/punch increase (usually a riff of drums) that I cannot "feel" on the Mojo and that I remember that I "feel" on the E1.

This morning I will test the Mojo as DAC (not amp) in my first system (roon+mojo+amp+speakers).

Since, impact apart, I find it awesome, I wonder if I will change my 300ohm HD650 with an 150ohm HD660S, if that impact/punch/fullness that I miss on the Mojo will come back or if these lackness is inside the signature of the Mojo. Because, due for it's comfort (I can use the Mojo in the bed without having too stuff in the bedroom) I could keep the Mojo and buy another headphone (keeping the HD650 for the living room).

PS: the Mojo runs very hot. Yesterday night, after two/three hours it was warm very much. I know it's normal but in the summer it will be fine that situation???

 

[jarnopp]

Still listening, still on the first charge after out of the box.

My thoughts are: everything is fine, fluid, articulate, detailed, tight and the soundstage is not narrow (as someone said here) and it's big in horizonal and in vertical way. I still hear the highs roll off yet.

I dont have any interference noise issue at all even stick to the phone (4g on).

But it still lacks of impact according to me and the post above me it's probably saying that technically.

I didn't make other A/B test with my Asus E1, but in my memory, there are parts in the songs when the dynamic/punch increase (usually a riff of drums) that I cannot "feel" on the Mojo and that I remember that I "feel" on the E1.

This morning I will test the Mojo as DAC (not amp) in my first system (roon+mojo+amp+speakers).

Since, impact apart, I find it awesome, I wonder if I will change my 300ohm HD650 with an 150ohm HD660S, if that impact/punch/fullness that I miss on the Mojo will come back or if these lackness is inside the signature of the Mojo. Because, due for it's comfort (I can use the Mojo in the bed without having too stuff in the bedroom) I could keep the Mojo and buy another headphone (keeping the HD650 for the living room).

PS: the Mojo runs very hot. Yesterday night, after two/three hours it was warm very much. I know it's normal but in the summer it will be fine that situation???

Mojo does run warm, especially if you are charging at the same time, you can play and charge at the same time, but if so, it’s recommended to start with a full charge.

I would say keep listening. What I started to notice after I first got Mojo was a feeling that I was hearing new things in soundstage I knew extremely well. When you can, for instance, feel like you are listening to a new master of Dark Side of the Moon after 30 years f playing the same CD, that is impressive. And you become addicted to the details and rhythm/timing Mojo provides.

 

[RiseFall123]

Could you advice an minijack to rca cable (brand and model) in the case i decide to keep it and to use it also with my main setup (which actually it is running just now with supermarket cables)?

 

[jarnopp]

Could you advice an minijack to rca cable (brand and model) in the case i decide to keep it and to use it also with my main setup (which actually it is running just now with supermarket cables)?

Audioquest makes both cables and a nifty adapter, if you already have RCA cables you like:

adapter: https://www.amazon.com/Audioquest-3...756500&sr=1-3&keywords=audioquest+mini-to-rca

cables (but there are many choices): https://www.amazon.com/Audioquest-E...756500&sr=1-6&keywords=audioquest+mini-to-rca

 

[RiseFall123]

I thought about the same (evergreen), about the adapter... i wont lose quality compared to the cable?

And... about a microusb to usb cable any advice? Anker?

About the line level output, stated from my amp's manual: “Except for PHONO input (19) all other inputs are line level and will accept virtually all currently available source components.”

That means that I don’t need to go to 2V as explained here in this thread or is always better to go to 2V anyway?

 

[jarnopp]

I thought about the same (evergreen), about the adapter... i wont lose quality compared to the cable?

And... about a microusb to usb cable any advice? Anker?

About the line level output, stated from my amp's manual: “Except for PHONO input (19) all other inputs are line level and will accept virtually all currently available source components.”

That means that I don’t need to go to 2V as explained here in this thread or is always better to go to 2V anyway?

Depending on your view of how much difference cables make, but the adapter is more versatile, especially if you already have decent RCA. I think the trade-off is balanced, because it may be more solid construction from 1/8 to RCA, whereas the cable may have smaller solder points. For micro-to-USB, the AQ Forest cable I've used, but again, your opinion of different digital cables should determine how much you might want to spend.

For voltage, I'd try 3V because it's convenient, but experiment with 3-4 clicks down (2.1 or 1.9V), and see if it sounds cleaner or not.

 

[RiseFall123]

Depending on your view of how much difference cables make, but the adapter is more versatile, especially if you already have decent RCA. I think the trade-off is balanced, because it may be more solid construction from 1/8 to RCA, whereas the cable may have smaller solder points. For micro-to-USB, the AQ Forest cable I've used, but again, your opinion of different digital cables should determine how much you might want to spend.

For voltage, I'd try 3V because it's convenient, but experiment with 3-4 clicks down (2.1 or 1.9V), and see if it sounds cleaner or not.

Very helpful!

About the voltage, when I click down colour remain the same, it’s should be so?

 

[435279]

Yeah you're right. My LG G6, v30, and Note 8 are cheap-ass phones. I'll be sure to upgrade.

I like suggestion #3, too. "Oh hey, you know this device we made for you to use with your mobile device? Keep it away from your mobile device!"

I'm using my Mojo right now, I love the thing, but WOW y'all...

I've been giving Rob's magnetic field radiation theory some thought, I'm not an expert though, just an armchair keyboard warrior.

Rob may well be correct, we know from electrical first principals that Magnetism and electric currents are related. I don't believe iron or steel shielding between the Phone and Mojo will help much here though.

I believe what may be happening is the magnetic field from the phone is generating a tiny electrical current in the headphone wire which is being fed back into the Mojo's sensitive circuitry. I find if I keep the headphone wire away from the phone it helps with the noise.

One of the selling points of the Mojo, the simple output driver circuit may be making things worse as there is less decoupling of noise fed back into the FPGA, the very design choice to give us a cleaner simpler output path is reducing quality when Mojo is used with a phone.

If there is any validity to this theory then magnetically shielding the headphone cable should quieten things down a bit. I not sure how to magnetically shield the entire length of the headphone cable, perhaps a ferrite core on the headphone wire close to the plug will help.

Now back to my armchair.

 

[jarnopp]

Very helpful!

About the voltage, when I click down colour remain the same, it’s should be so?

It doesn't change much, but it does change. It goes from more viloet to dark blue to light bllue on its way through the reverse rainbow. Here are pics, but hard to capture:

Line out:

-4 clicks:

-8 clicks:

 

[miketlse]

By the way @miketlse, sorry if this sounded short tempered or if I was having a go at you. Please don't take it that way, as it was not meant like that. I think you've always been on point.

I was a bit taken aback by your comments, largely because they seemed so 'out of character' for you.
I decided to delete my post, rather than accidently start an argument.
It's water under the bridge now.

 

[GreenBow]

Very helpful!

About the voltage, when I click down colour remain the same, it’s should be so?

Yes. Don't worry. Four clicks down is what we are all using for 2V line-level. ..I used to run my Mojo into a set of Q Acoustic BT3 that are active speakers. The line level on them was specified at 2V, and 2.25V as overload. With the Chord Mojo on 3V I used to hear clipping occasionally. When I used four clicks down from 3V, the problem was fully solved.

The colour of the volume orbs might not change much over four clicks, so no worries. On mine, one orb shifts colour very slightly over four clicks.

I would say just keep going with your Mojo, and please let us know what you think eventually. ... I clearly remember being in that, 'not sure place' at first. Other people have said they experienced the same when they started. I think possibly because there is so much information and spacialisation with the Mojo. It takes some time to figure it all out, when coming from a very different DAC. For me there was adjustment from a thick sound Meridian Explorer too, to the more natural Mojo. .... Either that, or burn in. (Am gonna get my ears clipped for mentioning burn in, haha.)

I was a bit taken aback by your comments, largely because they seemed so 'out of character' for you.
I decided to delete my post, rather than accidently start an argument.
It's water under the bridge now.

Thank you Mike; you rock.

I noticed you not posting for a couple of days, and hoped I hadn't hacked you off. I was getting worried.

I think my post was more of a, "Look look - read read". However I posted quickly in reply, and did not think out what I was doing. (As said earlier, absolutely not aimed at you. I was just kind of excited by what I thought was happening.)

I was also eventually rejoicing when I think I worked out what as happening. In that my Mojo has not lost any charge capacity in a year exactly now from new. That's got to be good for Chord's reputation, and my peace of mind.

 

[miketlse]

I noticed you not posting for a couple of days, and hoped I hadn't hacked you off. I was getting worried.

It is true that I have not been posting much for a week or so.
There are a few individuals hacking me off on the chord threads at the moment, and it has been made clear by some of them that my posts on the Poly thread are unwelcome, so i am taking a breather and saving my energy for when i can help someone in genuine need.

 

[Pepito]

Throwing in my 2 cents about the Mojo and AQ Jitterbug.

After doing some A/B with and without the AQ, I'd have to agree with some other members on this forum who think that the Jitterbug makes some noticeable sonic differences. I say noticeable and not improvement. The Jitterbug makes the bass more prominent and the mids are brought forward slightly as well. What this does to the sound is make it less transparent. The highs aren't rolled off, but they appear to since the bass and mids are taking up more space. The depth and soundstage seems to be reduced because the sound is much more "forward." This was all done with my CA Vega's, and to those that are familiar with them you can imagine how the Jitterbug would make it sound more congested. The overall signature is smoother without the Jitterbug.

I was first intrigued by elnero's description of the Mojo + Jitterbug because the Jitterbug helped my other setups sound better. But after spending some time without the Jitterbug I will be keeping it out.