[Aeromarine]

They did mention that they hired an expert in RFI when designing the Poly. I imagine that if it was a huge issue the mob would eat them alive. Let's hope it isn't an issue.

let's hope they can make poly "FLY"  

 

[NaiveSound]

No one seems to worry abot RFI. As far as my experience concerned, RFI kills good music.

It's more harmful than jitter.

I too am very worried about this

 

[oneguy]

I have to cellular off on my phone in order to maintain good sound output without interference.

 

[NaiveSound]

I have to cellular off on my phone in order to maintain good sound output without interference.

I know, it's awful

 

[oneguy]

I know, it's awful

I just made a quick aluminum foil shield with a single layer of household aluminum field to test out shielding the Mojo. It wasn't a wrap around design, I just placed it between my Japanese iPhone 6 and the Mojo.

It did reduce the amount of RFI from cellular but did not abate it completely. Now I will say that the LH Labs Vibratos' position relative to the Mojo changed the amount of audible RFI so it may have acted as 1) an antenna for RFI into the DAC or 2)the RFI was just output straight to the drivers and made the noise. So take that for what it's worth. There was no Wifi on for this test and I was operating on 3G.

I then turned on Airplane mode but left Wifi on. I tried to load a few page and didn't notice any RFI from Wifi. This was shielded and unshielded. Page load time we're quicker so maybe the RFI was to short lived for me to hear? I doubt it but it's possible.

So maybe Wifi 2.4ghz noise won't be an issue but I think that your phone in the vicinity of a mojo/Poly will be noisy with RFI. Possible solution: separate pockets.

EDIT: no foil hats were harmed in the creation of this experiment

EDIT: the ferrite ring included with the Mojo accessory pack was used with all of the tests above.

 

[NaiveSound]

I just made a quick aluminum foil shield with a single layer of household aluminum field to test out shielding the Mojo. It wasn't a wrap around design, I just placed it between my Japanese iPhone 6 and the Mojo.

It did reduce the amount of RFI from cellular but did not abate it completely. Now I will say that the LH Labs Vibratos' position relative to the Mojo changed the amount of audible RFI so it may have acted as 1) an antenna for RFI into the DAC or 2)the RFI was just output straight to the drivers and made the noise. So take that for what it's worth. There was no Wifi on for this test and I was operating on 3G.

I then turned on Airplane mode but left Wifi on. I tried to load a few page and didn't notice any RFI from Wifi. This was shielded and unshielded. Page load time we're quicker so maybe the RFI was to short lived for me to hear? I doubt it but it's possible.

So maybe Wifi 2.4ghz noise won't be an issue but I think that your phone in the vicinity of a mojo/Poly will be noisy with RFI. Possible solution: separate pockets.

EDIT: no foil hats were harmed in the creation of this experiment

Thanks


Well I have gotten SOME ferrite rings and I put on on the USB OTG from phone to mojo.

It reduced RF significantly, it helped a lot. I'd guess 75 to 85 percent, and that's with mojo and the phone velcroed together.

While I was happy and surprised something so simple worked. It (the RF) was still audiable enough to cause annoyance and break fidelity...

So I'm back to using a 18in cable and keeping the 2 separated.

I wish I could fix this... I wonder what else I can try.

 

[rkt31]

@NaiveSound, I think you want to use your phone and don't want to put it in airplane mode. airplane mode stops all rfi . you can think of using a cheap Android solely for transport like Redmi s1, it is small and streams dsd64 in dop without any problem via Uapp. it even streams dsd128 but sometimes there are occasional pops and clicks. or use shanling m1 as transport . btw I use fiio x3 2gen as transport to mojo.

 

[NaiveSound]

@NaiveSound, I think you want to use your phone and don't want to put it in airplane mode. airplane mode stops all rfi . you can think of using a cheap Android solely for transport like Redmi s1, it is small and streams dsd64 in dop without any problem via Uapp. it even streams dsd128 but sometimes there are occasional pops and clicks. or use shanling m1 as transport . btw I use fiio x3 2gen as transport to mojo.

I have a phone I used as transport, but... I always had in I airplane mode with WiFi turned on for Tidal hifi streaming.

RF was just everywhere...

 

[psikey]

They did mention that they hired an expert in RFI when designing the Poly. I imagine that if it was a huge issue the mob would eat them alive. Let's hope it isn't an issue.

 
If there's any hint of it they won't sell.
 
If I can as good as eliminate* it with my Mojo/Z5mini stacked using a ferrite ring on the USB cable and the thin Iron sheet between the Mojo & Z5 then I'm sure Chord have ensured there won't be any with the Poly.
 
 
* To clarify: the ring & sheet totally eliminated RF for me using both an S7 or Z5mini close coupled to the Mojo using WiFi & 3G but still can get a tiny bit on occasion if on 4G (depends on where I am).
 
As posted previously, some soft Iron sheet inserted in case (only used one piece ~0.3mm thick)
 

 

[psikey]

May also be down to frequency SIM uses as I've only tested with EE network in UK.

Sent from my SM-G930F using Tapatalk

 

[oneguy]

My test was with the ferrite ring supplied with Mojo accessory pack. I'll add that to my post.

 

[Mojo ideas]

Mojo ideas,

The only thing I'm worring about Poly is the RFI interference.

I have sometimes noticed a low volume of hiss, when putting Mojo near my other equipment --- either it's a cellphone, a laptop, or simply a tube amp, etc.

Especially when I'm using Mojo as a pure dac, I can hear the hiss being more noticable from my amp. And if I'm using Mojo as a dac/amp combo, the hiss is less noticable.

However, when I put Mojo far away from those equipments, all the hiss went away. It's so clean, the background is so dark, and the sound is smooth and nice.

Since I have repeatedly found Mojo quite vulnerable to external RFI interference and intermodulation noises, I'm really worring about Poly. What really worries me the most, is whether or not Poly will cause the same RFI problem to the Mojo.

So I hope Chord can find a solution to eliminate those unwanted hiss sound, so that I can safely purchase a Poly and get the clean result of sound that I want.

TL;DR: Will Poly cause RFI hiss noise to Mojo?

The design team of Poly are the most experienced in Europe and possibly anywhere. They are consultants regarding RFI and EMI issues to all the major Phone companies we don't expect and have not detected any problems or out of line issues. The sonic performance is directly inline with Poly's high performance expectations.

 

[Bengkia369]

The design team of Poly are the most experienced in Europe and possibly anywhere. They are consultants regarding RFI and EMI issues to all the major Phone companies we don't expect and have not detected any problems or out of line issues. The sonic performance is directly inline with Poly's high performance expectations.

Great to hear that, I already pre-ordered a Poly from my favorite shop in Singapore.

 

[Satir]

n/a

 

[miketlse]

  "believe AirPlay is limited to 16/44.1"
 
So AirPlay bottleneck using: Chord Mojo + Poly + Macbook Pro with wireless headphones capable of capturing greater than 44.1kHz/16-bit? If yes (with three-quarters of my library at and/or greater than 96kHz/24-bit) I'll wait for wireless technology software/hardware to catch up to (old school) wired connection.

 
Surely Airplay is a proprietary Apple standard - so it is Apple that must catch up, rather than wireless technology software/hardware in general, which is what your statement applies.