ibasso D3 Review!
Nov 19, 2008 at 4:56 AM Post #31 of 200

jamato8

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What people might also want to think about is why is the iphone putting out so much RF and what will be the effect on their brain? That is of greater concern to me as a health professional than interference on the sound but maybe the D3 is telling you something.
 
Nov 19, 2008 at 5:19 AM Post #32 of 200

HeadphoneAddict

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I see. It's definitely never been an issue with our 5 Verizon phones on the family plan - ATT GSM service is the usual culprit, and iPhone is worse than my old Sony 810i was.

Fortunately, the iPhone is only for data for me, not for use against my head - I dropped my verizon PDA phone and data plan for a normal phone, and used the money for the iPhone instead.
 
Nov 19, 2008 at 6:24 AM Post #33 of 200

paulybatz

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I spoke with another head-fier via PMs and he returned his because of RF interference on his commute using the D3. Im glad that you are not experiencing issues.

Quote:

Originally Posted by tomjtx /img/forum/go_quote.gif
Larry, of course he has the right to warn people of a valid issue.
But he has posted the same thing in numerous threads and I also have the right to tell him it's boring :)

Also, in another post he has unfairly made the assumption the D3 will have a problem if in the vicinity of all cellphones simply because he had an issue with his iphone.

He should explain his issue w/o making up other issues and it is unnecesary to repeat this in multiple threads.

I have used my D3 around many cellphones with no problem.

This unwarranted bashing in numerous posts is obnoxious and boring IMO.



 
Nov 19, 2008 at 6:27 AM Post #34 of 200

paulybatz

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Larry, being a DJ as well...my verizon phone never interfered with my PA system but cingular/ATT is aweful...it also interferes with my sons baby monitor. Anyway, thanks for helping to sustain my disdain a bit. I will likely keep the D3 and use it as a DAC and figure something else out for portable...or just buy a regular ipod.


Quote:

Originally Posted by HeadphoneAddict /img/forum/go_quote.gif
I see. It's definitely never been an issue with our 5 Verizon phones on the family plan - ATT GSM service is the usual culprit, and iPhone is worse than my old Sony 810i was.

Fortunately, the iPhone is only for data for me, not for use against my head - I dropped my verizon PDA phone and data plan for a normal phone, and used the money for the iPhone instead.



 
Nov 19, 2008 at 6:49 AM Post #35 of 200

HeadphoneAddict

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Quote:

Originally Posted by paulybatz /img/forum/go_quote.gif
Larry, being a DJ as well...my verizon phone never interfered with my PA system but cingular/ATT is aweful...it also interferes with my sons baby monitor. Anyway, thanks for helping to sustain my disdain a bit. I will likely keep the D3 and use it as a DAC and figure something else out for portable...or just buy a regular ipod.


Yeah, it is very fortunate that the iPhone doesn't interfere with the DAC line out. I actually discovered that I can run headphones from the line out cleanly, with the amp off, without RFI. You could try an IEM with it and a Shure volume attenuator out of the line out (I'll try that soon).

I also should check to see if the Macbook digital volume control will affect the D3 DAC line-out volume, like it does with the Travagans Green and Headstage USB DAC cable.
 
Nov 19, 2008 at 6:57 AM Post #36 of 200

Mikenet

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Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif
What people might also want to think about is why is the iphone putting out so much RF and what will be the effect on their brain? That is of greater concern to me as a health professional than interference on the sound but maybe the D3 is telling you something.


Quote:

Originally Posted by paulybatz
Larry, being a DJ as well...my verizon phone never interfered with my PA system but cingular/ATT is aweful...it also interferes with my sons baby monitor. Anyway, thanks for helping to sustain my disdain a bit. I will likely keep the D3 and use it as a DAC and figure something else out for portable...or just buy a regular ipod.


The reason that GSM phones tend to interfere more than CDMA phones isn't the total RF power, but the fact that GSM is always rapidly switching the transmitter on and off. If you have a non-linear device, some of this RF energy is going to be rectified into DC. If the RF is turning on for ~0.5ms every ~4.5ms, that DC is going to switch on and off very quickly and cause a lot of noise.

I can't comment on the total power used by 3G devices, as I am not too familiar with them. All other things equal, the faster you're transmitting data, the more power it takes to overcome noise. But not all things are equal between 3G devices and older devices, so I hesitate to draw any conclusions here.

Some RF is probably coupling from the iPhones transmitter into the audio output, as will always occur in such a small device with a minimum of shielding(who wants to carry around an 80 pound metal brick in their pocket...I doubt even most audiophiles would go that far
tongue.gif
). I wonder if iPhone is worse than any other music-playing phones in this regard. You could try adding some filtering between the phone and the D3 and see if that helped. I mean, filtering out the 800+ MHz range isn't likely to cause too much pain for audio.
 
Nov 19, 2008 at 7:51 AM Post #37 of 200

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Quote:

Originally Posted by Mikenet /img/forum/go_quote.gif
The reason that GSM phones tend to interfere more than CDMA phones isn't the total RF power, but the fact that GSM is always rapidly switching the transmitter on and off. If you have a non-linear device, some of this RF energy is going to be rectified into DC. If the RF is turning on for ~0.5ms every ~4.5ms, that DC is going to switch on and off very quickly and cause a lot of noise.

I can't comment on the total power used by 3G devices, as I am not too familiar with them. All other things equal, the faster you're transmitting data, the more power it takes to overcome noise. But not all things are equal between 3G devices and older devices, so I hesitate to draw any conclusions here.

Some RF is probably coupling from the iPhones transmitter into the audio output, as will always occur in such a small device with a minimum of shielding(who wants to carry around an 80 pound metal brick in their pocket...I doubt even most audiophiles would go that far
tongue.gif
). I wonder if iPhone is worse than any other music-playing phones in this regard. You could try adding some filtering between the phone and the D3 and see if that helped. I mean, filtering out the 800+ MHz range isn't likely to cause too much pain for audio.



Maybe you don't realize this, but the RFI occurs with the phone as much as 3 feet away from the D3, and not even plugged into the amp. I can have the D3 plugged into the USB of my Macbook, and the phone in my pocket and the amp (or other electronics) can go nuts.
 
Nov 19, 2008 at 8:05 AM Post #38 of 200

nocturnalsheet

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Quote:

Originally Posted by tomjtx /img/forum/go_quote.gif
Larry, of course he has the right to warn people of a valid issue.
But he has posted the same thing in numerous threads and I also have the right to tell him it's boring :)

Also, in another post he has unfairly made the assumption the D3 will have a problem if in the vicinity of all cellphones simply because he had an issue with his iphone.

He should explain his issue w/o making up other issues and it is unnecesary to repeat this in multiple threads.

I have used my D3 around many cellphones with no problem.

This unwarranted bashing in numerous posts is obnoxious and boring IMO.



hi tom,

i am from singapore and i do experience the RFI problem.

i have no idea why when i was testing the D3 at my 2 local audio shop i do not experience any RFI.

however on the train/bus journey, i am experiencing a lot of irritating RFI.

i do not own an iphone btw.

at home, i do experience a bit of RFI depending where my phone is at.

no doubt the D3 is a great piece of amp/dac but it is without its flaws.

i believe potential buyers will have to weigh the pros and cons before they take the leap of faith.

perhaps we should look into the ways to shield the D3 from RFI?

thanks
 
Nov 19, 2008 at 12:32 PM Post #39 of 200

palestofwhite

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Hi,

I was the one who returned my D3 due to severe RF interference in my region.

I live in Singapore, and it is a densely populated country. We're not as bad as Japan or Hong Kong, but close enough.

I believe it also boils down to the GSM or 3G modes of mobile service our carriers have chosen to adopt.

My Sony Ericsson M600i does in fact interfere but not as frequent as my iPhone. Though I do not use the phone as my primary source, the fact that you have them in the same bag, the phone and the amp with DAP, does not take away the RF problem.

And everyone else's phone in the train or public will have the same chance even if you leave home without one.

To me, the idea of having a portable amp is to carry it around to enjoy. If RF is going to restrict my Amp to only for home use, I don't see how that works out even if the sound is amazing.

I have to place my phone near me and in Vibration mode. I tend to miss calls or text messages while listening.

Regards.
 
Nov 19, 2008 at 3:17 PM Post #40 of 200

paulybatz

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I found that it has to be about 4 feet away to avoid the problems.
That is an expensive interconnect!
Im going to get an ipod...and another amp!

Quote:

Originally Posted by HeadphoneAddict /img/forum/go_quote.gif
Maybe you don't realize this, but the RFI occurs with the phone as much as 3 feet away from the D3, and not even plugged into the amp. I can have the D3 plugged into the USB of my Macbook, and the phone in my pocket and the amp (or other electronics) can go nuts.


 
Nov 19, 2008 at 8:19 PM Post #41 of 200

tomjtx

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Well, I don't know why I don't have the RFI prob you guys have.
Good RFI Karma? :)

Most of my friends have Iphones and they don't interfere when they are around.

I'll experiment some and see if I can get RFI and if not, maybe I can figure out why.

Meanwhile I will try to be less of a curmudgeon
very_evil_smiley.gif
 
Nov 19, 2008 at 8:53 PM Post #42 of 200

HeadphoneAddict

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Quote:

Originally Posted by tomjtx /img/forum/go_quote.gif
Well, I don't know why I don't have the RFI prob you guys have.
Good RFI Karma? :)

Most of my friends have Iphones and they don't interfere when they are around.

I'll experiment some and see if I can get RFI and if not, maybe I can figure out why.

Meanwhile I will try to be less of a curmudgeon
very_evil_smiley.gif



You would think of all people that I am a portable amp's best friend, yet I have to suffer with it, eh?
 
Nov 19, 2008 at 11:25 PM Post #43 of 200

glc

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I got lots of RFI once for the 30 minutes while I was using the iBasso mini to mini cable that came with the D3 to connect from the iBasso output jack to my headphone cables as an extension.

The minute I changed it out for to the regular SE530 cable or the volume control all RFI went away & have not come back.
 
Nov 20, 2008 at 1:32 AM Post #44 of 200

Gberg

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would using the ibasso D3 with my ipod touch be ok? Or is it just beside any iphone or phone seem to cause problems (which means bad for commutes). Hearing all this talk about interference problems doesn't make me happy.. I thought I was closing in on a decision..
 
Nov 20, 2008 at 2:00 AM Post #45 of 200

jamato8

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What IC is being used when these problems of interference arise?

The D3 is in a case that should do some shielding.
 

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