Sony Fontopia Plus earphones does not like mains power sup..

Archived from groups: rec.audio.tech (More info?)

This sounds like a grounding issue. You should speak to the sales people
where you bought it.

--

Jerry G.
======


"Ant" <pawnpacer@yahoo.com> wrote in message
news:1e41930a.0503051547.49e09865@posting.google.com...
I bought some Sony Fontopia Plus (MDR-ED21LP) earphones from Argos UK
a few days ago. I've noticed something very odd. When I use them with
an Apple iPod which is plugged into the mains (i.e. on charge) I hear
continuous background noise, like the background static noise you used
to get from a cheap portable tape player from years ago.

If I disconnect the iPod from the mains supply then the problem goes
away completely. If I plug it back in, the problem reappears. Also, if
I touch a metal part of my iPod, such as the casing or the remote
control, then that also removes the background noise completely!

I've noticed a similar thing with my laptop. If I use these earphones
with my Vaio while it is plugged into the mains then I get the same
problem. If I disconnect my Vaio from the mains then the problem goes
away completely. Also, if I touch any metal part of my Vaio (eg touch
the firewire port with my finger) then that removes the background
noice from the earphones too, exactly the same effect as touching my
iPod metal casing.

I have tried another pair of headphones and the problem does not occur
at all, even if I plug the Vaio into the mains supply.

So these Fontopia earphones don't seem to like the UK power supply!
Bizarre! Does anyone know if it's a grounding issue, or a frequency
interference issue?

Also, is this is a common issue with headphones, or with Fontopia
brand, or with quality control?

Thanks, Ant

Archived from groups: rec.audio.tech (More info?)

"Arny Krueger" <arnyk@hotpop.com> wrote in message news:<rMmdndf4-JgClbbfRVn-hw@comcast.com>...
> "Ant" <pawnpacer@yahoo.com> wrote in message
> news:1e41930a.0503051547.49e09865@posting.google.com
>
> > I bought some Sony Fontopia Plus (MDR-ED21LP) earphones from Argos UK
> > a few days ago. I've noticed something very odd. When I use them with
> > an Apple iPod which is plugged into the mains (i.e. on charge) I hear
> > continuous background noise, like the background static noise you used
> > to get from a cheap portable tape player from years ago.
>
> This would be in comparison with the phones that came with the iPod, right?
>
> I've never heard these relatively low-end phones, but if they have the "Sony
> Sound". they are probably a little hot on the high end. This means that any
> hissing coming from within the player would be accentuated compared to
> headphones with neutral sound or sound that is rolled-off on the high end.
>
> > If I disconnect the iPod from the mains supply then the problem goes
> > away completely.
>
> This means to me that the iPod is picking up noise from its line-operated
> power supply, or something else attached to the power supply. My
> recollection is that the iPod normally picks up power from its docking
> station which includes other kinds of connections, including computer port
> connections for either USB or Firewire. If these connections are connected
> to a computer, they could be adding to the noise situation. You might want
> to see what disconnecting them accomplishes. However I also seem to recall
> that the docking station may obtain power via them, so disconnecting them
> might not be a long term solution.
>
> > If I plug it back in, the problem reappears. Also, if
> > I touch a metal part of my iPod, such as the casing or the remote
> > control, then that also removes the background noise completely!
>
> This suggests to me that you have a problem with picking up noise via one of
> the connections to the iPod, all of which are routed thorugh the docking
> station. When you touch the case you may be partially grounding it through
> your body.
>
> I've worked with iPods, and this is not normal. It suggests a fault
> someplace, but as you can see there are many possible sources of problems,
> some of which may be hard to separate out.
>
> > I've noticed a similar thing with my laptop. If I use these earphones
> > with my Vaio while it is plugged into the mains then I get the same
> > problem. If I disconnect my Vaio from the mains then the problem goes
> > away completely.
>
> You may have some external interferance source in the room or nearby, or
> your power line may be picking up noise from an external source and dumping
> it into your computer gear.
>
> > Also, if I touch any metal part of my Vaio (eg touch
> > the firewire port with my finger) then that removes the background
> > noice from the earphones too, exactly the same effect as touching my
> > iPod metal casing.
>
> YOu shouldn't need to ground these components to have noise-free operation.
> What happens if you try to use your iPod at someone else's house?
>
> > I have tried another pair of headphones and the problem does not occur
> > at all, even if I plug the Vaio into the mains supply.
>
> I explained that at the beginning of the post.
>
> > So these Fontopia earphones don't seem to like the UK power supply!
> > Bizarre! Does anyone know if it's a grounding issue, or a frequency
> > interference issue?
>
> I suspect its environmental. Lots of people use any given model of Sony
> phones with Viao computers and iPods. I doubt that ehty are all having
> problems.
>
> > Also, is this is a common issue with headphones, or with Fontopia
> > brand, or with quality control?
>
> I suspect your environment. There could be something odd with how power is
> grounded in yourself, or something like that.


Thanks for the reply. Just to add:

1) I've tried the headphones with my vaio while it has been plugged
into the mains at another location (about 6 miles away), and I
observed the exact same problem.

2) The other phones I tried (which do not have the problem) were also
Sony (some larger headphones in this case). I only briefly tried the
supplied Apple earphones a couple of years ago and not used those
since. I'll try those out and post a follow up.

So far the only common factors I can see are the earphones and the UK
power supply frequency (not sure about electricity provider).

Ant