Stereo headphone combiner jack

N

nil spam

Guest
I've got two outputs from my digital tv box and my computer both going into
one jack which combines them into one input for my speakers. I've noticed
something wierd in that when I plug only one of the outputs from either
digibox/pc into the combiner and set the volume at a decent level and then
plug in the other output, the volume of both the inputs from the speakers
seems to diminish significantly. Conversely when I then set the output level
of the speakers at a nice volume and then unplug one of the two inputs the
volume increases significantly. Obviously I either have the digibox playing
sound or the pc playing sound but never both at the same time, I just like
to have them both plugged in so that I don't have to keep swapping the
cables around. The combiner was a cheapo unit from Maplins (UK equivalent of
Radio Shack) and is obviously a passive device but I never expected this to
happen. What's going on and how can I remedy it (on a budget if possible).
Thanks in advance!
 
I do not know exactly what your arrangement is (combined into one jack
on what device?) but it sounds as if this 'combiner' is simpy a
Y-connector that cross connects the two input sources to the output.
If so, it is no surprise to me that each input is partly shorting the
other. You need either a resistive mixer, an active mixer or just a
switch in order to avoid the problem.

Kal


On Thu, 6 Nov 2003 21:16:58 -0000, "nil spam" <no@spamplease.com>
wrote:

I've got two outputs from my digital tv box and my computer both going into
one jack which combines them into one input for my speakers. I've noticed
something wierd in that when I plug only one of the outputs from either
digibox/pc into the combiner and set the volume at a decent level and then
plug in the other output, the volume of both the inputs from the speakers
seems to diminish significantly. Conversely when I then set the output level
of the speakers at a nice volume and then unplug one of the two inputs the
volume increases significantly. Obviously I either have the digibox playing
sound or the pc playing sound but never both at the same time, I just like
to have them both plugged in so that I don't have to keep swapping the
cables around. The combiner was a cheapo unit from Maplins (UK equivalent of
Radio Shack) and is obviously a passive device but I never expected this to
happen. What's going on and how can I remedy it (on a budget if possible).
Thanks in advance!
Click to expand...
 
Kal,

I don't really know what to call this thing. It has three sockets, two for
inputs and one for output. The plug from my speakers goes into the output
and the two plugs from the digibox and PC go into the inputs. You're right
in saying it's basically a Y-connector. What exactly are the options you
mention (the first two that is), and how much would I expect to pay for one?

Thanks.

"Kalman Rubinson" <kr4@nyu.edu> wrote in message
news:l9glqvkkmhj2lufn58n8qmcdaajjngj6n1@4ax.com...
| I do not know exactly what your arrangement is (combined into one jack
| on what device?) but it sounds as if this 'combiner' is simpy a
| Y-connector that cross connects the two input sources to the output.
| If so, it is no surprise to me that each input is partly shorting the
| other. You need either a resistive mixer, an active mixer or just a
| switch in order to avoid the problem.
|
| Kal
|
|
| On Thu, 6 Nov 2003 21:16:58 -0000, "nil spam" <no@spamplease.com>
| wrote:
|
| >I've got two outputs from my digital tv box and my computer both going
into
| >one jack which combines them into one input for my speakers. I've noticed
| >something wierd in that when I plug only one of the outputs from either
| >digibox/pc into the combiner and set the volume at a decent level and
then
| >plug in the other output, the volume of both the inputs from the speakers
| >seems to diminish significantly. Conversely when I then set the output
level
| >of the speakers at a nice volume and then unplug one of the two inputs
the
| >volume increases significantly. Obviously I either have the digibox
playing
| >sound or the pc playing sound but never both at the same time, I just
like
| >to have them both plugged in so that I don't have to keep swapping the
| >cables around. The combiner was a cheapo unit from Maplins (UK equivalent
of
| >Radio Shack) and is obviously a passive device but I never expected this
to
| >happen. What's going on and how can I remedy it (on a budget if
possible).
| >Thanks in advance!
| >
|
 
On Thu, 6 Nov 2003 21:52:58 -0000, "nil spam" <no@spamplease.com>
wrote:

Kal,

I don't really know what to call this thing. It has three sockets, two for
inputs and one for output. The plug from my speakers goes into the output
and the two plugs from the digibox and PC go into the inputs. You're right
in saying it's basically a Y-connector.
Click to expand...
Doesn't it have a name/number on it? I am assuming that the signals
from your digital TV box and from your computer are ordinary
line-level analog audio. I am also assuming that you are using
self-powered speakers. Without knowing the specifics, I will again
assume that the powered speakers have a relatively high input
impedance. (Does it say anything on them?)

If so, you can make a resistive mixer by simply putting a 5-10Kohm
resistor in series with each of the four signal leads (2 stereo
sources). This should reduce all the levels very slightly but prevent
them from shunting each other.

See: http://www.wintektx.com/extras/making.htm

What exactly are the options you
mention (the first two that is), and how much would I expect to pay for one?
Click to expand...
Dunno offhand. See:
http://www.jacksmusicfactory.com/default.asp?section=Mixers&group=Mini_Mixers
or
http://www.wintektx.com/products/PAM/

Kal


"Kalman Rubinson" <kr4@nyu.edu> wrote in message
news:l9glqvkkmhj2lufn58n8qmcdaajjngj6n1@4ax.com...
| I do not know exactly what your arrangement is (combined into one jack
| on what device?) but it sounds as if this 'combiner' is simpy a
| Y-connector that cross connects the two input sources to the output.
| If so, it is no surprise to me that each input is partly shorting the
| other. You need either a resistive mixer, an active mixer or just a
| switch in order to avoid the problem.
|
| Kal
|
|
| On Thu, 6 Nov 2003 21:16:58 -0000, "nil spam" <no@spamplease.com
| wrote:
|
| >I've got two outputs from my digital tv box and my computer both going
into
| >one jack which combines them into one input for my speakers. I've noticed
| >something wierd in that when I plug only one of the outputs from either
| >digibox/pc into the combiner and set the volume at a decent level and
then
| >plug in the other output, the volume of both the inputs from the speakers
| >seems to diminish significantly. Conversely when I then set the output
level
| >of the speakers at a nice volume and then unplug one of the two inputs
the
| >volume increases significantly. Obviously I either have the digibox
playing
| >sound or the pc playing sound but never both at the same time, I just
like
| >to have them both plugged in so that I don't have to keep swapping the
| >cables around. The combiner was a cheapo unit from Maplins (UK equivalent
of
| >Radio Shack) and is obviously a passive device but I never expected this
to
| >happen. What's going on and how can I remedy it (on a budget if
possible).
| >Thanks in advance!
|
|
Click to expand...
 
"nil spam" <no@spamplease.com> wrote in message
news:boedoe$jda$1@uns-a.ucl.ac.uk...
I've got two outputs from my digital tv box and my computer both going
into
one jack which combines them into one input for my speakers. I've noticed
something wierd in that when I plug only one of the outputs from either
digibox/pc into the combiner and set the volume at a decent level and then
plug in the other output, the volume of both the inputs from the speakers
seems to diminish significantly. Conversely when I then set the output
level
of the speakers at a nice volume and then unplug one of the two inputs the
volume increases significantly. Obviously I either have the digibox
playing
sound or the pc playing sound but never both at the same time, I just like
to have them both plugged in so that I don't have to keep swapping the
cables around. The combiner was a cheapo unit from Maplins (UK equivalent
of
Radio Shack) and is obviously a passive device but I never expected this
to
happen. What's going on and how can I remedy it (on a budget if possible).
Thanks in advance!
Click to expand...
Take a look at the audio switch maplin part no A94AR

It's cream coloured, and about 2" long not green like in the photo. It's
designed to switch the connection choosing between headset and speakers to
one PC audio output. Might do what you want. All 3.5mm stereo jacks sockets.

Jc.
 
Kalman Rubinson wrote:

If so, you can make a resistive mixer by simply putting a 5-10Kohm
resistor in series with each of the four signal leads (2 stereo
sources). This should reduce all the levels very slightly but prevent
them from shunting each other.
Click to expand...
5-10K for _speaker-level_ stuff? That's not going to work well, not at
all...
 
nil spam wrote:

I've got two outputs from my digital tv box and my computer both going into
one jack which combines them into one input for my speakers. I've noticed
something wierd in that when I plug only one of the outputs from either
digibox/pc into the combiner and set the volume at a decent level and then
plug in the other output, the volume of both the inputs from the speakers
seems to diminish significantly. Conversely when I then set the output level
of the speakers at a nice volume and then unplug one of the two inputs the
volume increases significantly. Obviously I either have the digibox playing
sound or the pc playing sound but never both at the same time, I just like
to have them both plugged in so that I don't have to keep swapping the
cables around. The combiner was a cheapo unit from Maplins (UK equivalent of
Radio Shack) and is obviously a passive device but I never expected this to
happen. What's going on and how can I remedy it (on a budget if possible).
Thanks in advance!
Click to expand...
The one reply here that mentions a switch would seem to be your best bet.
Using resistors to connect both outputs is going to cause you signal loss, to
probably an unaccepable degree.

Note that by combining both sets of outputs in a direct fashion this way you
are risking damage to either or both of them!
 
On Thu, 06 Nov 2003 18:12:40 -0500, "Roy J. Tellason"
<rtellason@DONTSPAM MEblazenet.net> wrote:

Kalman Rubinson wrote:

If so, you can make a resistive mixer by simply putting a 5-10Kohm
resistor in series with each of the four signal leads (2 stereo
sources). This should reduce all the levels very slightly but prevent
them from shunting each other.

5-10K for _speaker-level_ stuff? That's not going to work well, not at
all...
Click to expand...
Please note that the suggestion was based on the assumption that the
speakers were self-powered and, therefore, their inputs were high
impedance line-level signals. 5-10K will work fine there.

Kal
 
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