What can I do to keep using an external speaker and volume control
with my 12" analog TVs? My knowledge of electronics is modest.

For 35 years, I've taken the tvs I have and plugged a larger speaker
into it, usually a 6x9 speaker cabinet from a 60's or 70's stereo or
maybe better**. If there was no jack, I'd put one in. I'd put a pot
in the circuit to adjust the volume. Mostly this was in the bedroom,
and also in the bathroom so I could watch tv from the bathtub, and
also in the basement. (**In 2 consecutive bathrooms, for 35 years,
I've been using a woofer, tweeter, and crossover from a 1930's record
player, mounted on a new piece of chipboard, covered in decorative
burlap and mounted in the corner between the ceiling and the wall of
the bathroom, with 45^ moldings I cut and stained.)

10 or 20 years ago, I ran out of tvs that used tubes and had to do
this with transistor tvs. It seemed not to work as well. I would have
to keep the volume closer to the top to avoid distortion. I only used
two wires, with the variable resistor in the circuit.

Are my suspicions correct,
a) that it didn't work as well because they were transistor tv's and
not tube tvs?
b) that if I used 3 wires, 2 wires from the tv to the pot and 2 wires
from the pot to the speaker, and used it as a voltage divider, I would
have a fixed load on the audio output so I would get less distortion,
but I would also have a lower maximum volume?

I've done this with 6 or 7 transistor tvs total, but the last two tvs
have failed with audio problems, distortion, although only after
several years use for each. The last one is a Sony 9" transistor tv,
about 20 or 30 years old. It had two earphone jacks, one that
disconnected the internal speaker and one that ran sound to the
earphone and the speaker both. I used the first jack, and because the
volume wasn't high enough, I bypassed the resistor in the jack circuit
which is meant to lower the volume for an earphone. Did doing this
ruin the audio output? -- The other tv that failed was 9" -- I
forget the brand -- and had two jacks, one for an earphone but come to
think of it, the second was for an external speaker, so maybe the
sound distortion failure there was coincidental? Or maybe even though
there was a jack, it wasn't fully capable of powering the speaker over
the course of years, an hour or two a day?


Now I have another Sony, this time 12 inches, also 20 or 30 years old,
with no jack afaict and I want to put one in, but I'd like to avoid
damaging the audio (even if it takes years to do it.)

Or I have a much newer tv with remote, but I would like to put a jack
in that and use the knob that is in the little box next to me in bed
to adjust the volume. It works much faster, easier, and with more
precision than remotes do. Now that I'm using a mechanical volume
control, I hate to go back to the remote.

So the problem/question is the same.


The other thing complicating this is that I've had a little tinnitus
in one ear since I was 10 or 20, I think, but since I'm 63 six months
ago, it has gotten louder. I can't tell if it is my ear causing the
problem or the tv, until the tv problem gets pretty bad. (I have an
appointment with the ear doctor, but not for 3 weeks.)

Sorry for the long post.
Thanks for any health you can give.

On Mar 4, 10:29*pm, mm wrote:
What can I do to keep using an external speaker and volume control
with my 12" analog TVs? *My knowledge of electronics is modest.

For 35 years, I've taken the tvs I have and plugged a larger speaker
into it, usually a 6x9 speaker cabinet from a 60's or 70's stereo or
maybe better**. *If there was no jack, I'd put one in. *I'd put a pot
in the circuit to adjust the volume. *Mostly this was in the bedroom,
and also in the bathroom so I could watch tv from the bathtub, and
also in the basement. *(**In 2 consecutive bathrooms, for 35 years,
I've been using a woofer, tweeter, and crossover from a 1930's record
player, mounted on a new piece of chipboard, covered in decorative
burlap and mounted in the corner between the ceiling and the wall of
the bathroom, with 45^ moldings I cut and stained.)

10 or 20 years ago, I ran out of tvs that used tubes and had to do
this with transistor tvs. *It seemed not to work as well. I would have
to keep the volume closer to the top to avoid distortion. *I only used
two wires, with the variable resistor in the circuit. *

Are my suspicions correct,
a) that it didn't work as well because they were transistor tv's and
not tube tvs?
b) that if I used 3 wires, 2 wires from the tv to the pot and 2 wires
from the pot to the speaker, and used it as a voltage divider, I would
have a fixed load on the audio output so I would get less distortion,
but I would also have a lower maximum volume?

I've done this with 6 or 7 transistor tvs total, but the last two tvs
have failed with audio problems, distortion, although only after
several years use for each. *The last one is a Sony 9" transistor tv,
about 20 or 30 years old. *It had two earphone jacks, one that
disconnected the internal speaker and one that ran sound to the
earphone and the speaker both. *I used the first jack, and because the
volume wasn't high enough, I bypassed the resistor in the jack circuit
which is meant to lower the volume for an earphone. *Did doing this
ruin the audio output? * -- The other tv that failed was 9" -- I
forget the brand -- and had two jacks, one for an earphone but come to
think of it, the second was for an external speaker, so maybe the
sound distortion failure there was coincidental? *Or maybe even though
there was a jack, it wasn't fully capable of powering the speaker over
the course of years, an hour or two a day?

Now I have another Sony, this time 12 inches, also 20 or 30 years old,
with no jack afaict and I want to put one in, but I'd like to avoid
damaging the audio (even if it takes years to do it.)

Or I have a much newer tv with remote, but I would like to put a jack
in that and use the knob that is in the little box next to me in bed
to adjust the volume. *It works much faster, easier, and with more
precision than remotes do. *Now that I'm using a mechanical volume
control, I hate to go back to the remote.

So the problem/question is the same.

The other thing complicating this is that I've had a little tinnitus
in one ear since I was 10 or 20, I think, but since I'm 63 six months
ago, it has gotten louder. I can't tell if it is my ear causing the
problem or the tv, until the tv problem gets pretty bad. *(I have an
appointment with the ear doctor, but not for 3 weeks.)

Sorry for the long post.
Thanks for any health you can give.

Run the television earphone output to an amp. It doesn't have to be
anything special. You could build a small one fairly easily. I'm
guessing, due to the increased strength in modern magnets, that newer
television speakers need less power to produce the same volume as
older speakers. So the audio amplifiers in the television are going
to have problems pushing those old current eaters. If you are driving
the external speakers directly, it would probably be a good idea to
match the impedances. A small audio transformer would do the trick for
cheap. You could integrate that into a small amp, with a gain and
volume pot, and even a balance and fade if you wanted to get fancy for
under 20 or 30 bucks. There are schematics all over the internet for
those sorts of things.

"mm" wrote in message
...
What can I do to keep using an external speaker and volume control
with my 12" analog TVs? My knowledge of electronics is modest.

For 35 years, I've taken the tvs I have and plugged a larger speaker
into it, usually a 6x9 speaker cabinet from a 60's or 70's stereo or
maybe better**. If there was no jack, I'd put one in. I'd put a pot
in the circuit to adjust the volume. Mostly this was in the bedroom,
and also in the bathroom so I could watch tv from the bathtub, and
also in the basement. (**In 2 consecutive bathrooms, for 35 years,
I've been using a woofer, tweeter, and crossover from a 1930's record
player, mounted on a new piece of chipboard, covered in decorative
burlap and mounted in the corner between the ceiling and the wall of
the bathroom, with 45^ moldings I cut and stained.)

10 or 20 years ago, I ran out of tvs that used tubes and had to do
this with transistor tvs. It seemed not to work as well. I would have
to keep the volume closer to the top to avoid distortion. I only used
two wires, with the variable resistor in the circuit.

Are my suspicions correct,
a) that it didn't work as well because they were transistor tv's and
not tube tvs?
b) that if I used 3 wires, 2 wires from the tv to the pot and 2 wires
from the pot to the speaker, and used it as a voltage divider, I would
have a fixed load on the audio output so I would get less distortion,
but I would also have a lower maximum volume?

I've done this with 6 or 7 transistor tvs total, but the last two tvs
have failed with audio problems, distortion, although only after
several years use for each. The last one is a Sony 9" transistor tv,
about 20 or 30 years old. It had two earphone jacks, one that
disconnected the internal speaker and one that ran sound to the
earphone and the speaker both. I used the first jack, and because the
volume wasn't high enough, I bypassed the resistor in the jack circuit
which is meant to lower the volume for an earphone. Did doing this
ruin the audio output? -- The other tv that failed was 9" -- I
forget the brand -- and had two jacks, one for an earphone but come to
think of it, the second was for an external speaker, so maybe the
sound distortion failure there was coincidental? Or maybe even though
there was a jack, it wasn't fully capable of powering the speaker over
the course of years, an hour or two a day?


Now I have another Sony, this time 12 inches, also 20 or 30 years old,
with no jack afaict and I want to put one in, but I'd like to avoid
damaging the audio (even if it takes years to do it.)

Or I have a much newer tv with remote, but I would like to put a jack
in that and use the knob that is in the little box next to me in bed
to adjust the volume. It works much faster, easier, and with more
precision than remotes do. Now that I'm using a mechanical volume
control, I hate to go back to the remote.

So the problem/question is the same.


The other thing complicating this is that I've had a little tinnitus
in one ear since I was 10 or 20, I think, but since I'm 63 six months
ago, it has gotten louder. I can't tell if it is my ear causing the
problem or the tv, until the tv problem gets pretty bad. (I have an
appointment with the ear doctor, but not for 3 weeks.)

Sorry for the long post.
Thanks for any health you can give.

How are you connecting your pot ? As a variable resistor in series with the
speaker ? Not as a variable resistor *across* the speaker, I hope ...

In general, simple transistor stages (and IC stages come to that) don't mind
too much, what impedance they have presented to them, as long as it's above
some minimum amount. In contrast, simple tube output stages also don't care
too much, as long as some maximum amount is not exceeded - ie semiconductor
stages don't like shorts, tube output stages don't like opens. So, as long
as you are connecting your pot as a variable resistor in series with the
speaker, and the speaker is not too chunky, and of the correct nominal
impedance, I see no reason why it would cause any damage to any
semiconductor output stage that you would find in a portable TV.

However, by just connecting a variable resistor in series with the speaker,
you are never going to get the volume down to zero, and the more you try, by
fitting higher value pots, the more one-ended the control range will become.

Putting a pot across the audio output pair (of wires), but connected as a
pot, not a variable resistor, (so with the 'top' of the pot track connected
to the output stage, and the wiper of the pot connected to the speaker, and
the 'bottom' of the pot common to both), will allow you to get down to zero,
without the load ever dropping to a 'short', but as you go higher in volume,
the impedance presented to the amplifier will still drop, as the speaker
becomes an increasing load in parallel with the pot track resistance.
Therefore, the value of the pot needs to be chosen so that the total load on
the output stage, when the volume is up high, is not below what the
manufacturers designed it to handle. Low value pots are not all that common,
so you may have to compromise a little. Be aware also, that the speaker
impedance in a modern small portable TV might not be the low 4 or 8 ohms
that you are used to finding in a tube TV. They can be as high as 32 ohms,
as are many modern headphones.

Arfa

Hi!

a) that it didn't work as well because they were transistor
tv's and not tube tvs?

Probably not. One has to consider how powerful the amplifiers in these
TVs were, as well as the speaker they were driving.

In late model CRT type TVs, I've noticed that the speakers usually have
oddball impedance ratings, such as 3.2 ohms. If you were to drive an
external speaker, its impedance rating probably wouldn't match that of
the speaker the TV came with, and that could result in poor audio
performance.

I think what you really want to do is to buy a TV with either a line
level output or earphone connection that could be plugged into an
outboard amplifier (such as an old stereo receiver?) If a used set were
acceptable, you could probably get one for as little as $5-30 depending
upon condition and screen size. And maybe if you offered to haul it
away, you could get one for free.

The same is true of an old stereo receiver. Lots of perfectly good
choices are around, and most would be very cheap. Look in secondhand
stores. An old stereo receiver or audio amplifier would do a very good
job of driving the speaker you have. It would be much better than any
TV's built in audio amplifier would be.

William

On Fri, 5 Mar 2010 09:40:58 -0000, "Arfa Daily"
wrote:


"mm" wrote in message
.. .
What can I do to keep using an external speaker and volume control
with my 12" analog TVs? My knowledge of electronics is modest.

For 35 years, I've taken the tvs I have and plugged a larger speaker
into it, usually a 6x9 speaker cabinet from a 60's or 70's stereo or
maybe better**. If there was no jack, I'd put one in. I'd put a pot
in the circuit to adjust the volume. Mostly this was in the bedroom,
and also in the bathroom so I could watch tv from the bathtub, and
also in the basement. (**In 2 consecutive bathrooms, for 35 years,
I've been using a woofer, tweeter, and crossover from a 1930's record
player, mounted on a new piece of chipboard, covered in decorative
burlap and mounted in the corner between the ceiling and the wall of
the bathroom, with 45^ moldings I cut and stained.)

10 or 20 years ago, I ran out of tvs that used tubes and had to do
this with transistor tvs. It seemed not to work as well. I would have
to keep the volume closer to the top to avoid distortion. I only used
two wires, with the variable resistor in the circuit.

Are my suspicions correct,
a) that it didn't work as well because they were transistor tv's and
not tube tvs?
b) that if I used 3 wires, 2 wires from the tv to the pot and 2 wires
from the pot to the speaker, and used it as a voltage divider, I would
have a fixed load on the audio output so I would get less distortion,
but I would also have a lower maximum volume?

I've done this with 6 or 7 transistor tvs total, but the last two tvs
have failed with audio problems, distortion, although only after
several years use for each. The last one is a Sony 9" transistor tv,
about 20 or 30 years old. It had two earphone jacks, one that
disconnected the internal speaker and one that ran sound to the
earphone and the speaker both. I used the first jack, and because the
volume wasn't high enough, I bypassed the resistor in the jack circuit
which is meant to lower the volume for an earphone. Did doing this
ruin the audio output? -- The other tv that failed was 9" -- I
forget the brand -- and had two jacks, one for an earphone but come to
think of it, the second was for an external speaker, so maybe the
sound distortion failure there was coincidental? Or maybe even though
there was a jack, it wasn't fully capable of powering the speaker over
the course of years, an hour or two a day?


Now I have another Sony, this time 12 inches, also 20 or 30 years old,
with no jack afaict and I want to put one in, but I'd like to avoid
damaging the audio (even if it takes years to do it.)

Or I have a much newer tv with remote, but I would like to put a jack
in that and use the knob that is in the little box next to me in bed
to adjust the volume. It works much faster, easier, and with more
precision than remotes do. Now that I'm using a mechanical volume
control, I hate to go back to the remote.

So the problem/question is the same.


The other thing complicating this is that I've had a little tinnitus
in one ear since I was 10 or 20, I think, but since I'm 63 six months
ago, it has gotten louder. I can't tell if it is my ear causing the
problem or the tv, until the tv problem gets pretty bad. (I have an
appointment with the ear doctor, but not for 3 weeks.)

Sorry for the long post.
Thanks for any health you can give.

Thank you, Sansui. At this stage of my life, it would be a problem to
try to build this myself. I'm so far behind on everything else I have
to do, and falling further behind. But I appreciate your suggestion
that an amp is the way to go.

My only real question is at the very end**.

How are you connecting your pot ? As a variable resistor in series with the
speaker ?

Yes.

Not as a variable resistor *across* the speaker, I hope ...

No.

In general, simple transistor stages (and IC stages come to that) don't mind
too much, what impedance they have presented to them, as long as it's above
some minimum amount.

Well, it never goes below the resistance of the speaker (two speakers
in the same box maybe).

In contrast, simple tube output stages also don't care
too much, as long as some maximum amount is not exceeded - ie semiconductor
stages don't like shorts, tube output stages don't like opens. So, as long
as you are connecting your pot as a variable resistor in series with the
speaker, and the speaker is not too chunky, and of the correct nominal
impedance, I see no reason why it would cause any damage to any
semiconductor output stage that you would find in a portable TV.

However, by just connecting a variable resistor in series with the speaker,
you are never going to get the volume down to zero, and the more you try, by
fitting higher value pots, the more one-ended the control range will become.

Yes, that's a problem, but I think I reached a good compromise. The
only time I want the volume that low is when I'm on the phone, and the
phone in the bathroom no longer works. (Some wiring problem between
the basement and the second floor.) But I get fewer calls than I used
to anyhow, and I let the machine answer. Before I had a tv with
remote in the bathroom, there was no way to turn off the tv while I
was in the tub, but in the bedroom I can turn it off if I want to have
a phone conversation.

Putting a pot across the audio output pair (of wires), but connected as a
pot, not a variable resistor, (so with the 'top' of the pot track connected
to the output stage, and the wiper of the pot connected to the speaker, and
the 'bottom' of the pot common to both), will allow you to get down to zero,
without the load ever dropping to a 'short', but as you go higher in volume,
the impedance presented to the amplifier will still drop,

Oh, yeah. I didn't think of that.

as the speaker
becomes an increasing load in parallel with the pot track resistance.
Therefore, the value of the pot needs to be chosen so that the total load on
the output stage, when the volume is up high, is not below what the
manufacturers designed it to handle. Low value pots are not all that common,
so you may have to compromise a little. Be aware also, that the speaker
impedance in a modern small portable TV might not be the low 4 or 8 ohms
that you are used to finding in a tube TV. They can be as high as 32 ohms,
as are many modern headphones.

**So maybe the Sony tv, even though 20 years old or more, has a higher
impedance speaker, and plugging in an 8 or maybe even 4 ohm speaker to
the earphone jack, after bypassing the resistor that led to the jack,
COULD have damaged the output stage of the audio??

Actually, encouraged by the replies I got here, I changed to the other
Sony tv, about the same age, and plugged in same speaker without
bypassing the internal resistor, and the sound was still bad, but
afterwards still not bad when listening through the built-in speaker.
So maybe there is a problem with the speaker I've been using for 26
years. More in my reply to William.

Thanks to Sansui and you and William and Kalman for the help.


Arfa

On Fri, 05 Mar 2010 09:30:36 -0600, "William R. Walsh"
m wrote:

Hi!

a) that it didn't work as well because they were transistor
tv's and not tube tvs?

Probably not. One has to consider how powerful the amplifiers in these
TVs were, as well as the speaker they were driving.

In late model CRT type TVs, I've noticed that the speakers usually have
oddball impedance ratings, such as 3.2 ohms. If you were to drive an
external speaker, its impedance rating probably wouldn't match that of
the speaker the TV came with, and that could result in poor audio
performance.

I think what you really want to do is to buy a TV with either a line
level output or earphone connection that could be plugged into an
outboard amplifier (such as an old stereo receiver?) If a used set were
acceptable, you could probably get one for as little as $5-30 depending
upon condition and screen size. And maybe if you offered to haul it
away, you could get one for free.

I'll keep my eyes open.

The same is true of an old stereo receiver. Lots of perfectly good
choices are around, and most would be very cheap. Look in secondhand

That sounds good. Hey, come to think of it, I had a portable record
player from the 70's, the kind where the turntable folded up into the
cabinet, and the speakers were on the sides but could be pulled apart,
and it was very broken so I cut off the top, with the transistor
stereo amp, about 14 inches wide by 4 high by 6 deep. It's in the
basement, I just have to find it.

stores. An old stereo receiver or audio amplifier would do a very good
job of driving the speaker you have. It would be much better than any
TV's built in audio amplifier would be.

William

On Sat, 06 Mar 2010 14:21:53 -0500, mm
wrote:

The current amplified speaker has 3 RCA jacks, In L & R,
and Out SP. Do you know what SP stands for?


(I have no use for Out now. It's a monaural tv and I don't have the
other speaker anyhow, but i'm curious what SP might stand for.)

Well, what speaker is it?

Kal

On Sat, 06 Mar 2010 18:07:23 -0500, Kalman Rubinson
wrote:

On Sat, 06 Mar 2010 14:21:53 -0500, mm
wrote:

The current amplified speaker has 3 RCA jacks, In L & R,
and Out SP. Do you know what SP stands for?

Maybe SP stands for speaker, even though both S and P are capitalized.


(I have no use for Out now. It's a monaural tv and I don't have the
other speaker anyhow, but i'm curious what SP might stand for.)

Well, what speaker is it?

Oh, it has no brand name at all! No model number, or embossing, other
than the labeling of the inputs and output. Just a little gold strip
that says "Made in somwhere", I didn't look where.

And it seems like a nice one. It's heavy for its size, has two
speakers, 4 or 5 inches and a smaller one, showing through the metal
grill, has some sort of air port in the front (that might be real, not
just a decoration) volume, bass, and treble controls, an LED that
lights when it's on, and has a real cord with a plug, not an AC
adapter.

I think I've only once before seen something decent with no brand or
model number.

Kal

snip


The current amplified speaker has 3 RCA jacks, In L & R,
and Out SP. Do you know what SP stands for?


(I have no use for Out now. It's a monaural tv and I don't have the
other speaker anyhow, but i'm curious what SP might stand for.)

Thanks to you and to Sansui, Afra, and William.

I would imagine that it is an abreviation for SP-eaker, and is the standard
arrangement for this type of setup, where the little stereo amplifier is
contained within one cabinet, along with the power supply electronics and
one speaker connected to one channel output of the amp, and the other
channel output is connected to that "SP" socket, to where you would connect
the other cabinet, which contains just a speaker ...

Arfa

On Mon, 8 Mar 2010 01:57:48 -0000, "Arfa Daily"
wrote:

snip


The current amplified speaker has 3 RCA jacks, In L & R,
and Out SP. Do you know what SP stands for?


(I have no use for Out now. It's a monaural tv and I don't have the
other speaker anyhow, but i'm curious what SP might stand for.)

Thanks to you and to Sansui, Afra, and William.

I would imagine that it is an abreviation for SP-eaker, and is the standard
arrangement for this type of setup, where the little stereo amplifier is
contained within one cabinet, along with the power supply electronics and
one speaker connected to one channel output of the amp, and the other
channel output is connected to that "SP" socket, to where you would connect
the other cabinet, which contains just a speaker ...

Thanks. That must be it.

I never got the other part, so this works out well since the tv is
monaural.

Arfa