Bought a Y-cable

Now that I sometimes have the laptop and desktop running at the same
time, and I listen to web radio from whichever is doing a better job, I
wanted a Y-connector, to send both signals to the speakers.

There appeared to be many but most just split off the mic from
headphones. Another was 8 feet long but the part where the wires could
go in 2 directions to two sources was not shown. It definitely wasn't
all 8 feet. Another was only 20 cm long. I don't know what that is
in real numbers but I dont' think it will work, especially if the
computers were on opposite sides of even the same desk.

One was 6 feet long with totally separate wires. 6 feet is more than
enough but I think this means 12 feet. I have the url if you want.

But this last one had a warning, given liteally 3 times in the Amazon
webpage offering it for sale:
"Don't play two different audio at the same time. If the audio from
two different audio sources, more powerful output will be louder."

Well of course, and so what, and won't anyone notice this right away?

Is there a valid reason for this warning?

micky wrote:
Now that I sometimes have the laptop and desktop running at the same
time, and I listen to web radio from whichever is doing a better job, I
wanted a Y-connector, to send both signals to the speakers.

There appeared to be many but most just split off the mic from
headphones. Another was 8 feet long but the part where the wires could
go in 2 directions to two sources was not shown. It definitely wasn't
all 8 feet. Another was only 20 cm long. I don't know what that is
in real numbers but I dont' think it will work, especially if the
computers were on opposite sides of even the same desk.

One was 6 feet long with totally separate wires. 6 feet is more than
enough but I think this means 12 feet. I have the url if you want.

But this last one had a warning, given liteally 3 times in the Amazon
webpage offering it for sale:
"Don't play two different audio at the same time. If the audio from
two different audio sources, more powerful output will be louder."

Well of course, and so what, and won't anyone notice this right away?

Is there a valid reason for this warning?

A foreigner teaching you some maths ?

The person neglected to consider if the signals
are identical, but one signal is upside-down with respect
to the other signal. The net signal output is zero :-)

PC#1 ----- R1 ------+
|
+---------- In, computer speakers, 10K input impedance
|
PC#2 ----- R2 ------+

You're allowed to make your own cables, you know.

For R1 and R2, you could make then both 390 ohms
or both 560 ohms, without too much impact on the results.
A finite resistance prevents one PC from back-driving
the other PC (when they both are offering 1 ohm output
impedance drive). At one time, the PC output impedance
was a bit closer to 32 ohms, now it's a lower impedance
like 1 ohm.

If you do this, maybe it's hard on the PCs. The PC
end is AC coupled. But we don't want excuses when
something breaks, so I can't recommend doing it this way.
If even one person gets a broken computer sound, that's
one too many.

PC#1 ---------------+
|
+---------- In, computer speakers
|
PC#2 ---------------+

Back when we had a Radio Shack, all the gubbins
needed were available.

And you can't put diodes in those paths either...
"10% distortion" sounds, are the result. Would
sound like crap.

Paul

In alt.comp.os.windows-10, on Sat, 08 Aug 2020 20:53:51 -0400, Paul
wrote:

micky wrote:
Now that I sometimes have the laptop and desktop running at the same
time, and I listen to web radio from whichever is doing a better job, I
wanted a Y-connector, to send both signals to the speakers.

There appeared to be many but most just split off the mic from
headphones. Another was 8 feet long but the part where the wires could
go in 2 directions to two sources was not shown. It definitely wasn't
all 8 feet. Another was only 20 cm long. I don't know what that is
in real numbers but I dont' think it will work, especially if the
computers were on opposite sides of even the same desk.

One was 6 feet long with totally separate wires. 6 feet is more than
enough but I think this means 12 feet. I have the url if you want.

But this last one had a warning, given liteally 3 times in the Amazon
webpage offering it for sale:
"Don't play two different audio at the same time. If the audio from
two different audio sources, more powerful output will be louder."

Well of course, and so what, and won't anyone notice this right away?

Is there a valid reason for this warning?

A foreigner teaching you some maths ?

That might be it. When the Chinese warn you that one sound might be
louder than another, that's enough to make me think MS might insist on a
password even when I'm alone.

The person neglected to consider if the signals
are identical, but one signal is upside-down with respect
to the other signal. The net signal output is zero :-)

PC#1 ----- R1 ------+
|
+---------- In, computer speakers, 10K input impedance
|
PC#2 ----- R2 ------+

You're allowed to make your own cables, you know.

Yes, but it's so much easier to buy.

For R1 and R2, you could make then both 390 ohms
or both 560 ohms, without too much impact on the results.
A finite resistance prevents one PC from back-driving
the other PC (when they both are offering 1 ohm output
impedance drive). At one time, the PC output impedance
was a bit closer to 32 ohms, now it's a lower impedance
like 1 ohm.

If you do this, maybe it's hard on the PCs. The PC
end is AC coupled. But we don't want excuses when
something breaks, so I can't recommend doing it this way.
If even one person gets a broken computer sound, that's
one too many.

PC#1 ---------------+
|
+---------- In, computer speakers
|
PC#2 ---------------+

Back when we had a Radio Shack, all the gubbins
needed were available.

I miss Radio Shack.

And you can't put diodes in those paths either...
"10% distortion" sounds, are the result. Would
sound like crap.

Paul

On 09/08/2020 01.55, micky wrote:
Now that I sometimes have the laptop and desktop running at the same
time, and I listen to web radio from whichever is doing a better job, I
wanted a Y-connector, to send both signals to the speakers.

Don't do that, plain and simple. You risk burning one or two of the outputs.

You need a mixer, and AFAIK they don't do that for power (loudspeaker
output).

--
Cheers, Carlos.

On 09/08/2020 15.27, Carlos E.R. wrote:
On 09/08/2020 01.55, micky wrote:
Now that I sometimes have the laptop and desktop running at the same
time, and I listen to web radio from whichever is doing a better job, I
wanted a Y-connector, to send both signals to the speakers.

Don't do that, plain and simple. You risk burning one or two of the
outputs.

You need a mixer, and AFAIK they don't do that for power (loudspeaker
output).


I forgot.

You can use the "line out" outputs connected to a plain mixer (which can
be done with a few resistors), and then and amplifier with speakers as
usual.

--
Cheers, Carlos.

In alt.comp.os.windows-10, on Sun, 9 Aug 2020 15:36:50 +0200, "Carlos
E.R." wrote:

On 09/08/2020 15.27, Carlos E.R. wrote:
On 09/08/2020 01.55, micky wrote:
Now that I sometimes have the laptop and desktop running at the same
time, and I listen to web radio from whichever is doing a better job, I
wanted a Y-connector, to send both signals to the speakers.

Don't do that, plain and simple. You risk burning one or two of the
outputs.

What if I only play sound from one at a time? but use the Y-cable so I
don't have to get up and move the current cable each time?

You need a mixer, and AFAIK they don't do that for power (loudspeaker
output).

Could your warning be what prompted their garbled warning?


I forgot.

You can use the "line out" outputs connected to a plain mixer (which can
be done with a few resistors), and then and amplifier with speakers as
usual.

On 8/8/20 8:13 PM, micky wrote:

[snip]

I miss Radio Shack.

Especially when there used to be people there who know things.
--
Mark Lloyd
http://notstupid.us/

"If there is a God, atheism must strike Him as less of an insult than
religion." [Edmond and Jules de Goncourt]

micky,

What if I only play sound from one at a time? But use the Y-cable
so I don't have to get up and move the current cable each time?

The "no work" solution ? Mute the PC you do not want to hear the sound of.

Another possibility would be to use Pauls schematic with the two resistors,
and use a special switch (three positions*) which disconnects either PC#1 or
PC#2 when in the left or right positions, but connects both when in the
middle one.

* Like this one (too many outputs, but exactly 3 positions) :
https://nl.rs-online.com/web/p/rotary-switches/0320708/

For the first switch connect the center and /left/ contacts (along the rim)
(and than to a PC#1),
For the second switch connect the center and /right/ contacts (along the
rim) (and thanto a PC#2),

Than connect, for both used switches, the "P" contacts (the ones tward the
center) (and than to the speakers).

Yeah, that will need some handywork. :-)

Another way would be the below, which pulls the unwanted signal to Zero
(killing it)

http://farm8.staticflickr.com/7282/9...b5d04df7_o.gif

The resistor values will probably need some adjusting though (schematic
found by throwing "passive crossfader" into Google).

Regards,
Rudy Wieser

On 09/08/2020 18.38, micky wrote:
In alt.comp.os.windows-10, on Sun, 9 Aug 2020 15:36:50 +0200, "Carlos
E.R." wrote:

On 09/08/2020 15.27, Carlos E.R. wrote:
On 09/08/2020 01.55, micky wrote:
Now that I sometimes have the laptop and desktop running at the same
time, and I listen to web radio from whichever is doing a better job, I
wanted a Y-connector, to send both signals to the speakers.

Don't do that, plain and simple. You risk burning one or two of the
outputs.

What if I only play sound from one at a time? but use the Y-cable so I
don't have to get up and move the current cable each time?

You can still damage the other computer.


You need a mixer, and AFAIK they don't do that for power (loudspeaker
output).

Could your warning be what prompted their garbled warning?

Yes.

--
Cheers, Carlos.

In alt.comp.os.windows-10, on Sat, 08 Aug 2020 21:13:51 -0400, micky
wrote:

In alt.comp.os.windows-10, on Sat, 08 Aug 2020 20:53:51 -0400, Paul
wrote:

micky wrote:
Now that I sometimes have the laptop and desktop running at the same
time, and I listen to web radio from whichever is doing a better job, I
wanted a Y-connector, to send both signals to the speakers.

There appeared to be many but most just split off the mic from
headphones. Another was 8 feet long but the part where the wires could
go in 2 directions to two sources was not shown. It definitely wasn't
all 8 feet. Another was only 20 cm long. I don't know what that is
in real numbers but I dont' think it will work, especially if the
computers were on opposite sides of even the same desk.

One was 6 feet long with totally separate wires. 6 feet is more than
enough but I think this means 12 feet. I have the url if you want.

But this last one had a warning, given liteally 3 times in the Amazon
webpage offering it for sale:
"Don't play two different audio at the same time. If the audio from
two different audio sources, more powerful output will be louder."

Well of course, and so what, and won't anyone notice this right away?

Is there a valid reason for this warning?

A foreigner teaching you some maths ?

That might be it. When the Chinese warn you that one sound might be
louder than another, that's enough to make me think MS might insist on a
password even when I'm alone.

The person neglected to consider if the signals
are identical, but one signal is upside-down with respect
to the other signal. The net signal output is zero :-)

PC#1 ----- R1 ------+
|
+---------- In, computer speakers, 10K input impedance
|
PC#2 ----- R2 ------+

You're allowed to make your own cables, you know.


So the resistors are meant to solve the problem that Carlos brought up??
Burning out one of the sound outputs.

Yes, but it's so much easier to buy.

This answer was when I thought I coudl just buy it.

For R1 and R2, you could make then both 390 ohms
or both 560 ohms, without too much impact on the results.

Carlos, you raised the problem more clearly to this newbie than Paul
did.

Do you agree that 300 or 560 ohm reistors oin the positive wires of the
Y-connector would keep the sound output from burning out?

A finite resistance prevents one PC from back-driving
the other PC (when they both are offering 1 ohm output
impedance drive). At one time, the PC output impedance
was a bit closer to 32 ohms, now it's a lower impedance
like 1 ohm.

If you do this, maybe it's hard on the PCs. The PC
end is AC coupled. But we don't want excuses when
something breaks, so I can't recommend doing it this way.
If even one person gets a broken computer sound, that's
one too many.

PC#1 ---------------+
|
+---------- In, computer speakers
|
PC#2 ---------------+

Back when we had a Radio Shack, all the gubbins
needed were available.

I miss Radio Shack.

And you can't put diodes in those paths either...
"10% distortion" sounds, are the result. Would
sound like crap.

Paul

micky wrote:
In alt.comp.os.windows-10, on Sat, 08 Aug 2020 21:13:51 -0400, micky
wrote:

In alt.comp.os.windows-10, on Sat, 08 Aug 2020 20:53:51 -0400, Paul
wrote:

micky wrote:
Now that I sometimes have the laptop and desktop running at the same
time, and I listen to web radio from whichever is doing a better job, I
wanted a Y-connector, to send both signals to the speakers.

There appeared to be many but most just split off the mic from
headphones. Another was 8 feet long but the part where the wires could
go in 2 directions to two sources was not shown. It definitely wasn't
all 8 feet. Another was only 20 cm long. I don't know what that is
in real numbers but I dont' think it will work, especially if the
computers were on opposite sides of even the same desk.

One was 6 feet long with totally separate wires. 6 feet is more than
enough but I think this means 12 feet. I have the url if you want.

But this last one had a warning, given liteally 3 times in the Amazon
webpage offering it for sale:
"Don't play two different audio at the same time. If the audio from
two different audio sources, more powerful output will be louder."

Well of course, and so what, and won't anyone notice this right away?

Is there a valid reason for this warning?
A foreigner teaching you some maths ?
That might be it. When the Chinese warn you that one sound might be
louder than another, that's enough to make me think MS might insist on a
password even when I'm alone.
The person neglected to consider if the signals
are identical, but one signal is upside-down with respect
to the other signal. The net signal output is zero :-)

PC#1 ----- R1 ------+
|
+---------- In, computer speakers, 10K input impedance
|
PC#2 ----- R2 ------+

You're allowed to make your own cables, you know.


So the resistors are meant to solve the problem that Carlos brought up??
Burning out one of the sound outputs.


You'd have to figure out what the impedance of the
coupling cap is, at some frequency of interest, to
see what kind of currents might be flowing.

The idea of resistors, was to make it impossible to burn out.

You could drop the resistors to 32 ohms if you want, as the
chip is guaranteed to drive a 32 ohm load.

The 600 ohm loading range is supposed to be for ports
not in headphone-boost state. If you had 5.1 audio and
three ORing cables, some of the ports would not be boosted.

I haven't been "sitting around trying to burn out the audio
port on my computer" with regard to this question :-) I have
no field data to offer on how easy it is to damage sound
ports via carelessness.

If you run the signals into a mixer, then you have a better
idea what each cable faces as a load. And it's a very light
load.

My computer speakers used to be done with a "receiver" type
appliance, and it had a mixer and select buttons. There was
also a remote. If the VCR was sending video to the TV set,
I could flip the computer speakers to "listen" to the signal
from the VCR (two RCA jacks), and then I could be listening
to stereo (instead of the mono the TV provides from its single
tinny speaker).

Paul

On 24/08/2020 06.26, micky wrote:
In alt.comp.os.windows-10, on Sat, 08 Aug 2020 21:13:51 -0400, micky
wrote:

In alt.comp.os.windows-10, on Sat, 08 Aug 2020 20:53:51 -0400, Paul
wrote:

micky wrote:
Now that I sometimes have the laptop and desktop running at the same
time, and I listen to web radio from whichever is doing a better job, I
wanted a Y-connector, to send both signals to the speakers.

There appeared to be many but most just split off the mic from
headphones. Another was 8 feet long but the part where the wires could
go in 2 directions to two sources was not shown. It definitely wasn't
all 8 feet. Another was only 20 cm long. I don't know what that is
in real numbers but I dont' think it will work, especially if the
computers were on opposite sides of even the same desk.

One was 6 feet long with totally separate wires. 6 feet is more than
enough but I think this means 12 feet. I have the url if you want.

But this last one had a warning, given liteally 3 times in the Amazon
webpage offering it for sale:
"Don't play two different audio at the same time. If the audio from
two different audio sources, more powerful output will be louder."

Well of course, and so what, and won't anyone notice this right away?

Is there a valid reason for this warning?

A foreigner teaching you some maths ?

That might be it. When the Chinese warn you that one sound might be
louder than another, that's enough to make me think MS might insist on a
password even when I'm alone.

The person neglected to consider if the signals
are identical, but one signal is upside-down with respect
to the other signal. The net signal output is zero :-)

PC#1 ----- R1 ------+
|
+---------- In, computer speakers, 10K input impedance
|
PC#2 ----- R2 ------+

You're allowed to make your own cables, you know.


So the resistors are meant to solve the problem that Carlos brought up??
Burning out one of the sound outputs.

It is not that easy.

It the resistors are high value, you hear nothing. If they are low, the
outputs are still in danger. Plus, there is the issue of impedance coupling.

I repeat: just don't do that.


Yes, but it's so much easier to buy.

This answer was when I thought I coudl just buy it.

For R1 and R2, you could make then both 390 ohms
or both 560 ohms, without too much impact on the results.

Carlos, you raised the problem more clearly to this newbie than Paul
did.

Do you agree that 300 or 560 ohm reistors oin the positive wires of the
Y-connector would keep the sound output from burning out?

It would render the speakers silent as well...



--
Cheers, Carlos.

Carlos E.R. wrote:
On 24/08/2020 06.26, micky wrote:
In alt.comp.os.windows-10, on Sat, 08 Aug 2020 21:13:51 -0400, micky
wrote:

In alt.comp.os.windows-10, on Sat, 08 Aug 2020 20:53:51 -0400, Paul
wrote:

micky wrote:
Now that I sometimes have the laptop and desktop running at the same
time, and I listen to web radio from whichever is doing a better
job, I
wanted a Y-connector, to send both signals to the speakers.

There appeared to be many but most just split off the mic from
headphones. Another was 8 feet long but the part where the wires
could
go in 2 directions to two sources was not shown. It definitely
wasn't
all 8 feet. Another was only 20 cm long. I don't know what that is
in real numbers but I dont' think it will work, especially if the
computers were on opposite sides of even the same desk.

One was 6 feet long with totally separate wires. 6 feet is more than
enough but I think this means 12 feet. I have the url if you want.

But this last one had a warning, given liteally 3 times in the Amazon
webpage offering it for sale:
"Don't play two different audio at the same time. If the audio
from
two different audio sources, more powerful output will be louder."

Well of course, and so what, and won't anyone notice this right away?

Is there a valid reason for this warning?

A foreigner teaching you some maths ?

That might be it. When the Chinese warn you that one sound might be
louder than another, that's enough to make me think MS might insist on a
password even when I'm alone.

The person neglected to consider if the signals
are identical, but one signal is upside-down with respect
to the other signal. The net signal output is zero :-)

PC#1 ----- R1 ------+
|
+---------- In, computer speakers, 10K input
impedance
|
PC#2 ----- R2 ------+

You're allowed to make your own cables, you know.


So the resistors are meant to solve the problem that Carlos brought up??
Burning out one of the sound outputs.

It is not that easy.

It the resistors are high value, you hear nothing. If they are low, the
outputs are still in danger. Plus, there is the issue of impedance
coupling.

I repeat: just don't do that.


Yes, but it's so much easier to buy.

This answer was when I thought I coudl just buy it.

For R1 and R2, you could make then both 390 ohms
or both 560 ohms, without too much impact on the results.

Carlos, you raised the problem more clearly to this newbie than Paul
did.

Do you agree that 300 or 560 ohm reistors oin the positive wires of the
Y-connector would keep the sound output from burning out?

It would render the speakers silent as well...

You're thinking of driving unamplified speakers in this case.

This is not for applications like headphone mixing. Headphones, like
coned speakers, are low impedance. Adding any series resistance when
driving a low impedance load, that would be bad from a user
experience perspective. Too quiet output. Not zero output, but...
a hearing test level of output.

300
PC#1 ----- R1 ------+ Voltage divider action would occur...
Gnd |
+---------- 32 ohm load (Ground connections used
300 | but not shown)
PC#2 ----- R2 ------+
Gnd Gnd 32 ohm load = headphones

*******

Amplified speakers have high input impedance. In fact, my
amplified speakers have 70,000 ohm min input. And some
computer LineIn signals, are 7pF to ground, so there is little
low pass filter effect from 300 ohms more resistance.

300
PC#1 ----- R1 ------+
|
+---------- 10000 ohm amplified speaker input
300 |
PC#2 ----- R2 ------+


I checked the specs on a sound chip input, and the capacitance
to ground on the sound chip is 7pF. This gives a minimal LPF
effect.

https://www.electronics-tutorials.ws.../filter_2.html

fc = 1 = 1 = 75.5MHz cutoff (passes 20KHz audio)
--------- ------------------------
2pi R C 6.28 * 301ohm * 7*10^-12

Paul

I use an analog 3.5mm Y splitter from my HDTV and PC to my Logitech
Z-2300 speakers (2.1 setup). However, I noticed when my HDTV is on, its
right speaker's volume is lowered from my PC's audio.
--
Life's so loco! ..!.. *isms, sins, hates, (d)evil, illnesses (e.g., COVID-19/2019-nCoV/SARS-CoV-2), deaths (RIP), interruptions, stresses, heat waves, fires, out(r)ages, dramas, unlucky #4, 2020, greeds, bugs (e.g., crashes & female mosquitoes), etc.
Note: A fixed width font (Courier, Monospace, etc.) is required to see this signature correctly.
/\___/\ Ant(Dude) @ http://aqfl.net & http://antfarm.home.dhs.org /
/ /\ /\ \ http://antfarm.ma.cx. Please nuke ANT if replying by e-mail.
| |o o| |
\ _ /
( )

On 24/08/2020 18.32, Paul wrote:
Carlos E.R. wrote:
On 24/08/2020 06.26, micky wrote:
In alt.comp.os.windows-10, on Sat, 08 Aug 2020 21:13:51 -0400, micky wrote:
In alt.comp.os.windows-10, on Sat, 08 Aug 2020 20:53:51 -0400, Paul wrote:
micky wrote:


The person neglected to consider if the signals
are identical, but one signal is upside-down with respect
to the other signal. The net signal output is zero :-)

Â*Â* PC#1 ----- R1 ------+
Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* |
Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* +---------- In, computer speakers, 10K input
impedance
Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* |
Â*Â* PC#2 ----- R2 ------+

You're allowed to make your own cables, you know.


So the resistors are meant to solve the problem that Carlos brought up??
Burning out one of the sound outputs.

It is not that easy.

It the resistors are high value, you hear nothing. If they are low,
the outputs are still in danger. Plus, there is the issue of impedance
coupling.

I repeat: just don't do that.


Yes, but it's so much easier to buy.

This answer was when I thought I coudl just buy it.

For R1 and R2, you could make then both 390 ohms
or both 560 ohms, without too much impact on the results.

Carlos, you raised the problem more clearly to this newbie than Paul
did.

Do you agree that 300 or 560 ohm reistors oin the positive wires of the
Y-connector would keep the sound output from burning out?

It would render the speakers silent as well...

You're thinking of driving unamplified speakers in this case.

Certainly.


This is not for applications like headphone mixing. Headphones, like
coned speakers, are low impedance. Adding any series resistance when
driving a low impedance load, that would be bad from a user
experience perspective. Too quiet output. Not zero output, but...
a hearing test level of output.

Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* 300
Â*PC#1 ----- R1 ------+Â*Â*Â*Â*Â* Voltage divider action would occur...
Â*GndÂ*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* |
Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* +---------- 32 ohm loadÂ*Â*Â*Â*Â*Â*Â* (Ground connections
used
Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* 300Â*Â*Â*Â*Â*Â* |Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â *Â*Â*Â*Â*Â* but not shown)
Â*PC#2 ----- R2 ------+
Â*GndÂ*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â *Â*Â*Â*Â*Â* GndÂ*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* 32 ohm load =
headphones


Something like 10 times less volume.

And we are making the assumption that the power transistors (ok, small
power for earphones) can cope with a little power coming in from the
output. They probably can, but they are not calculated for this.


*******

Amplified speakers have high input impedance. In fact, my
amplified speakers have 70,000 ohm min input. And some
computer LineIn signals, are 7pF to ground, so there is little
low pass filter effect from 300 ohms more resistance.

Sure, no problem with those. A "line output" is calculated to be
connected to a passive (resistive) mixer.


Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* 300
Â*PC#1 ----- R1 ------+
Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* |
Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* +---------- 10000 ohm amplified speaker input
Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* 300Â*Â*Â*Â*Â*Â* |
Â*PC#2 ----- R2 ------+


I checked the specs on a sound chip input, and the capacitance
to ground on the sound chip is 7pF. This gives a minimal LPF
effect.

https://www.electronics-tutorials.ws.../filter_2.html

Â*Â* fc =Â*Â*Â*Â* 1Â*Â*Â*Â*Â* =Â*Â*Â*Â*Â* 1Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* =Â* 75.5MHz cutoff (passes
20KHz audio)
Â*Â*Â*Â*Â*Â*Â* ---------Â*Â*Â* ------------------------
Â*Â*Â*Â*Â*Â*Â*Â* 2pi R CÂ*Â*Â*Â* 6.28 * 301ohm * 7*10^-12

Â*Â* Paul


--
Cheers, Carlos.