[Listen2this1]

I am having a issue lately and it is getting out of control. I have a 3g iPhone (i do not know if the phone matters) and if the phone is within 10 feet or so to my amp it will cause some interference, sounds like crazy digital static. I have heard this when it is next to the alarm clock, but have never had this problem with my can amp until lately.

Is there anything I can do? Is there anything I can do in the design of the next amp to decrease these chances?

 

[olblueyez]

Move the phone to more than 10 feet away from the amp.

 

[gadgetman]

It's been discussed here before. There are some solutions mentioned in those threads.

But the solution in general is use this forum's search function.

 

[Emooze]

Edit: Nevermind

 

[olblueyez]

Quote:

Originally Posted by gadgetman /img/forum/go_quote.gif It's been discussed here before. There are some solutions mentioned in those threads. But the solution in general is use this forum's search function.

Or you could just sharpen your pencil and be constructive.

Shielded cables may reduce the problem slightly but in general moving it away from the amp or disabling the network on your phone are your best two options.

 

[qusp]

if the amp isnt shielded properly then shielding the cables will do nothing to help the issue. for instance I have an iphone 3G too and I actually used to regularly use it with my pico with no problem of interference at all. well when it would switch to 2G coverage if I was out of range I would hear a ping. but while in 3G operation I could leave the phone on with all functionality intact; I could send email, use the internet, make calls texts etc. all without issue. either your coverage isnt great and its forever pinging the tower or your amp needs to be better shielded. when I borrowed a friends ibasso amp for a few days i had all sorts of problems. in both cases I didnt use shielded interconnects, so I think it has little to do with it

 

[ILAMtitan]

The interference you get when a phone call comes in is regularly called the GSM buzz. It doesn't effect the 3G phones as much because they do run at a much higher frequency, even for voice.

I've seen people kill the buzz using ferrite beads on their audio lines, right next to the amp. I haven't tried it personally though; I find it easier to just put my phone somewhere else.

 

[zkool448]

Yup it drives me nuts especially when I'm listening to some tunes while driving, and all of a sudden I get an incoming call -- interferance noise come out of my aftermarket head unit and speakers.

zk

 

[Uncle Erik]

Your cell phone is actually a radio transceiver more than a phone. Cells put out up to 0.25W of power and they check in periodically with the nearest cell tower, whether or not you're using the phone.

What you're hearing is RFI interference from the phone. It broadcasts and your amp picks up the signal. RFI can be a tricky beast to tame. It's sorb of like waterproofing something where you can't see the water, it reflects off some materials and comes in through small cracks.

The most obvious way to solve it is to keep your amp away from the phone. Shielded cables, ferrite beads and other methods can work, but RFI can still get in. If you're building an amp, be sure to use an aluminum case - it's great shielding. I think Nevada Surplus has some cases that are RFI tight at a good price. Still, try to move your rig away from the phone. Radio signal strength drops off exponentially with distance.

 

[Juaquin]

I use my iPhone as a portable source - you can shield the cable, amp, and headphones as much as you want, but the signal coming from the phone itself is destroyed by the interference - I have to turn off all the networks to use it for audio, and then I miss calls

 

[Good Times]

Quote:

Originally Posted by Juaquin /img/forum/go_quote.gif I use my iPhone as a portable source - you can shield the cable, amp, and headphones as much as you want, but the signal coming from the phone itself is destroyed by the interference - I have to turn off all the networks to use it for audio, and then I miss calls

Weird, my iPhone is as silent as my iPod as a source. I wonder what the varying factor is then.....

 

[Listen2this1]

The option of moving it more than 10 feet away is a pain due to that would be in the next room. It is kinda of hard to hear a phone with cans on and having a wall in between. I can see the major down fall being my enclosure.

I have a Millett Max, so here is the question, Is it the tubes or the solid state part of the amp causing the problems. If it is the amp I can maybe line the top layer of the chassis with a copper sheet. If it is the tubes I will be out of luck because they are outside of the enclosure.

 

[Emooze]

I'm going on guess but I'm sure its more the wires in the amp than actual component. Antennas are just long, stiff (sorry) wires anyways. After that I'd say the tubes because they are standing ou outside the case and absolutely shielding-free. Just my $0.02

 

[zeroibis]

You could switch to CDMA and not have the problem and still get your calls...

crap, forgot I was trolling... yea just let this thread die again. (oops)

 

[Heretic Architect]

Hello, there.
I'm having big trouble with my Little Dot 1+. After all kinds of tests, I too finally found out the noise i heard was coming from my phone.
I need to have the phone around because i work with it, so I ask: Is there a way to isolate the amp itself? Maybe opening it and applying tin foil to the inside of the casing? Or the tubes are gonna get the interference anyway?
I also found the interference gets louder if the headphone cable touches certain surfaces or metal objects...
Thanks in advance.