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Subject: Re: Line out vs headphone jack
From: Bradley Alexander (storm_at_tux.org)
Date: 2003-04-02


On Mon, 2003-03-31 at 23:38, Michael O'Quinn wrote:

> Are you sure it's the Jukebox and not the car stereo? Have you tried
> plugging something else into the line out jack to see if it works? I just
> plugged some headphones into the line out jack, and I heard the music,
> although not very loud. But it was enough to verify that the signal was
> present in both channels.

I have not plugged in headphones, because they were not readily
available, but I have tried it in two different cars. Added to the fact
taht the cassette adapter worked in the headphone jack of the Archos but
not the line.

> In general you won't burn anything out connecting the headphone output to
> a line input. In fact, I do it all the time. I have an amp that is a
> good amp, but it's input is not terribly sensitive, so the extra boost
> from the headphone amp in the Jukebox (such as it is) give the input stage
> of the amp a signal more to it's liking.
>
> The voltages are actually pretty close. The difference is that the
> headphone jack is (a) adjustable, and (b) capable of supplying more
> current, and (c) capable of supplying a slightly higher voltage signal.
> Since a line input has a high impedance, it draws very little current from
> either output jack, so there's no problem. The signal will become
> horribly distorted before it gets high enough to damage your equipment.

Excellent. I was brought up in the "never ever ever use a phone output
to a line input because of the voltage/current difference" days.

> You can test if it's the jack by just wiggling the plug while it's
> playing. If you hear anything, even just crackling that changes as you
> move it, I'd suspect something mechanical like the plug, jack, or cord.
> OTOH, since you heard a sudden pop out of the blue, followed by a dead
> channel, I suspect something is most likely blown.

I'll give that a try. Thanks Michael.

> Michael

-- 
--Brad
============================================================================
Bradley M. Alexander                |
Debian Developer, Security Engineer |   storm [at] tux.org
Debian/GNU Linux Developer          |   storm [at] debian.org
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