FiiO Mont Blanc/E12 portable headphone amp, 880mW, slim design, full metal case. Bass boost and Cross feed!
May 20, 2013 at 9:30 PM Post #1,951 of 3,739
Quote:
I have called from one cellphone to another (both less than 50sm away from E12) - no audible effect.
The EMI issue might have been limited to E12 V1.

 
GSM or CDMA or WCDMA ? The GSM will have bigger EMI issue
 
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May 21, 2013 at 6:43 AM Post #1,956 of 3,739
Quote:
I have called from one cellphone to another (both less than 50sm away from E12) - no audible effect.
The EMI issue might have been limited to E12 V1.

 
What about wifi interference? I seem to recall there are some who reported on jitters when there's any type of wifi equipment nearby (smartphones, laptops, tablets, routers, those sorta things).
 
May 21, 2013 at 10:39 AM Post #1,957 of 3,739
Quote:
X3 can support any earphones or headphone which used 3.5mm connector. not matter it is TRS or TRRS. 

 
That may well be true, but are we not talking about E12 here, did I miss something.
 
I am seeing a lot of variance in the TRRS connectors these days which is why I asked the question. I suspect, but have no concrete proof that a fair amount of RF interference is being caused by the connections with TRRS connectors.
 
May 21, 2013 at 10:58 AM Post #1,958 of 3,739
Quote:
 
What about wifi interference? I seem to recall there are some who reported on jitters when there's any type of wifi equipment nearby (smartphones, laptops, tablets, routers, those sorta things).


I have placed E12 on top of my router - no audible effect.
 
May 21, 2013 at 4:39 PM Post #1,959 of 3,739
I have a TP-Link TD-W8980 (2.4GHz + 5GHz) and I didn't notice any audible noise with the E12 placed right on the unit.

Also no noise with older routers (Netgear DGN2000 and D-Link DSL G624T).
 
May 22, 2013 at 12:44 AM Post #1,960 of 3,739
I'm getting terrible noise through my DT770 Pros connected to my HTC One with the amp placed right on top of the phone, which it has to be using the short cable supplied (the F8 cable).
 
Originally I thought my longer 3.5mm to 3.5mm right angle cable might be to blame, it's longer so i can freely rotate the phone to watch videos etc, but after less than a day's use I can see it's still the case.
 
I'm getting like the "GSM noise" you get when putting a 2G phone near amps/speakers that aren't shielded.
 
So i'm hoping a cable like this can help:
http://www.ebay.com.au/itm/2m-HQ-OFC-Shielded-3-5mm-Stereo-Jack-to-Jack-Cable-Gold-/200827575095?pt=AU_Television_Accessories&hash=item2ec2419b37
 
I don't get this noise when the DT770s are plugged into the phone "naked" and it used to be very rare with my E11.
 
If the new OFC cable doesn't work, the only solution appears to be a 3 to 5 metre cable, and keep the two devices in seperate pockets.
 
I'm not sure i'm desperate enough to pay the price this ebay seller wants however, LOL:
http://www.ebay.com.au/itm/3m-3-5mm-Dual-Right-Angle-Male-Jack-to-Jack-Stereo-Audio-Cable-006049-/190729178914?pt=UK_Computing_Sound_Vision_Audio_Cables_Adapters&hash=item2c68584f22
 
*ahem* or this one:
http://www.ebay.com.au/itm/2m-3-5mm-Dual-Right-Angle-Male-Jack-to-Jack-Stereo-Audio-Cable-006048-/380474428220?pt=UK_Computing_Sound_Vision_Audio_Cables_Adapters&hash=item58960b0b3c
 
May 22, 2013 at 1:04 AM Post #1,961 of 3,739
Quote:
I have called from one cellphone to another (both less than 50sm away from E12) - no audible effect.
The EMI issue might have been limited to E12 V1.

 
I have E12 v2 and the amp has to be on top of the smartphone to get this effect. By moving it 3-4 cm away you can overcome the issue but that's impossible if all the gear is in one pocket.
 
The answer is to have the amp in a seperate pocket - the more i read about this problem the more I think that's the solution.
 
I've just ordered a 3 metre 3.5mm cable with one end having a right angle plug (to go into my phone) so that should fix the problem. I'm hoping to have it by Friday and will report back here when i do.
(seperate to the OFC links i posted above, and it only cost me $5 Australian - i'm still keen to get the OFC cable though as it's thicker and will be of nicer quailty)
 
May 24, 2013 at 4:34 AM Post #1,964 of 3,739
Quote:
I think I have found the EMI issue. When the phone is using mobile Internet (over GSM) - the noise is very loud.
No problem with GSM calls or WiFi Internet.

 
Here in Australia i'm still getting some noise when I use a mobile wifi hotspot, unless my hotspot is in a different pocket, so i'm having some success there - so I might have my pocket wifi in right jacket pocket, the amp in my left jacket pocket and my phone in my right pants pocket or inside jacket pocket (which is higher up than the right jacket pocket).
 
In summer I might have a bit of a problem lol.
 
I use a seperate mobile wifi hotspot for streaming music often due to the cost of data on my main provider being so high. The 2nd provider is cheap but unreliable, and useless for voice calls, so i do need both.
 
So it might depend on what frequencies your mobile internet is using. On 900 (2G/3G) and 850mhtz (3G) the noise is quite loud, i can really hear it inside buildings and lifts. At 2100mhtz (3G) and 1800mhtz (4G) the noise is reduced, but still there. Again keeping any RF emitting devices away from the amp (by 5cm - that's 2 inches for you Americans) seems to be a solution.
 
I'll report back on what difference a shielded cable between the amp and the phone makes when it comes, but i think the noise could be generated by the amp itself, not it's cabling.
 
*edit* The reason why a lot of people have success with using wifi instead is because the wifi transmitter is much further away from the amp than your phone is. When I walk into my house still wearing my headphones these interference issues go away as I jump on the home wifi.
 

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