Paralleled Amplifier Wiring

[j r powell]

Hi,
I have a small stereo amplifier which came with two tiny 4ohm 3watt speakers.
I'd like to combine the two channels of the amp in order to drive one, slightly
larger, 8ohm 4watt speaker.
The amp is of the non-bridgeable type, so I assume parallel wiring would be
required - combining the two outputs together. I have read that small resistors
are required in parallel configuration, to enable proper current sharing between
the amplifiers, as without them the two amps would fight each other and
overheat. Can anyone tell me the correct values for these resistors, and where
they should be placed?

thanks,
jamie.

 

[Arfa Daily]

Hi,
I have a small stereo amplifier which came with two tiny 4ohm 3watt
speakers.
I'd like to combine the two channels of the amp in order to drive one,
slightly larger, 8ohm 4watt speaker.
The amp is of the non-bridgeable type, so I assume parallel wiring would
be required - combining the two outputs together. I have read that small
resistors are required in parallel configuration, to enable proper current
sharing between the amplifiers, as without them the two amps would fight
each other and overheat. Can anyone tell me the correct values for these
resistors, and where they should be placed?

thanks,
jamie.

How very rude ... d :-\

Arfa

 

[Arfa Daily]

Hi,
I have a small stereo amplifier which came with two tiny 4ohm 3watt
speakers.
I'd like to combine the two channels of the amp in order to drive one,
slightly larger, 8ohm 4watt speaker.
The amp is of the non-bridgeable type, so I assume parallel wiring would
be required - combining the two outputs together. I have read that small
resistors are required in parallel configuration, to enable proper current
sharing between the amplifiers, as without them the two amps would fight
each other and overheat. Can anyone tell me the correct values for these
resistors, and where they should be placed?

thanks,
jamie.

How very rude ... d :-\

Arfa

 

[j r powell]

How very rude ... d :-\

Well... he follows me around usenet and trolls me.

 

[David Nebenzahl]

I have a small stereo amplifier which came with two tiny 4ohm 3watt speakers.
I'd like to combine the two channels of the amp in order to drive one, slightly
larger, 8ohm 4watt speaker.
The amp is of the non-bridgeable type, so I assume parallel wiring would be
required - combining the two outputs together. I have read that small resistors
are required in parallel configuration, to enable proper current sharing between
the amplifiers, as without them the two amps would fight each other and
overheat. Can anyone tell me the correct values for these resistors, and where
they should be placed?

Have you tried simply using a pair of 8-ohm speakers with the amp?
Chances are they'd work (less power, but shouldn't harm the amp).

 

[j r powell]

Have you tried simply using a pair of 8-ohm speakers with the amp? Chances are
they'd work (less power, but shouldn't harm the amp).

I have, but then the audio output is too quiet for my requirements.

 

[William Sommerwerck]

Have you tried simply using a pair of 8-ohm speakers

I have, but then the audio output is too quiet for my requirements.

I'm not being sarcastic -- but how do you know that paralleling the outputs
will produce a significant increase in power? Ignoring the very pertinent
question of how to do this /correctly/, the most you could get is a 3dB
increase, which is plainly audible, but hardly a large increase.

 

[j r powell]

I'm not being sarcastic -- but how do you know that paralleling the outputs
will produce a significant increase in power? Ignoring the very pertinent
question of how to do this /correctly/, the most you could get is a 3dB
increase, which is plainly audible, but hardly a large increase.

A small increase is better than nothing.

 

[William Sommerwerck]

Have you tried simply using a pair of 8-ohm speakers

A small increase is better than nothing.

No, it isn't. Not when it requires a lot of work, and will be only slightly
audible.

"Forget about the whole thing." -- The Lady from Philadelphia

 

[j r powell]

No, it isn't. Not when it requires a lot of work, and will be only slightly
audible.

Fitting resistors is hardly a lot of work. I just need someone who knows their
stuff, to answer my original question.

 

[David Nebenzahl]

Fitting resistors is hardly a lot of work. I just need someone who knows their
stuff, to answer my original question.

So, William, what is the correct answer here (value of resistors)? I'm
curious now, too.

 

[William Sommerwerck]

I'm not being sarcastic -- but how do you know that paralleling the

So, William, what is the correct answer here (value of resistors)? I'm
curious now, too.

I don't see where I'm obliged to provide an answer, but here's what I
believe, to the best of my understanding...

Assuming that both channels have the same output impedance, and the output
levels are closely matched, then (if the outputs are directly paralleled)
there will be /no/ current flow from one channel into the other, and the
total amount of current that /could/ be delivered will be doubled. But if
the load impedance remains the same, there will be no increase in current
flow and no increase in volume level. You would need a speaker of half the
impedance to gain more power.

I think that's correct. Anybody want to agree or disagree?

 

[Phil Allison]

"j r powell"

I have a small stereo amplifier which came with two tiny 4ohm 3watt
speakers.
I'd like to combine the two channels of the amp in order to drive one,
slightly larger, 8ohm 4watt speaker.
The amp is of the non-bridgeable type, so I assume parallel wiring would
be required - combining the two outputs together.

** The only way to go here is to use "bridge mode".

Parallel wiring of the outputs is not only 100% useless it will almost
certainly destroy both amplifier channels.

I have read that small resistors are required in parallel configuration,
to enable proper current sharing between the amplifiers,

** Complete crap.

There is such of lot of it on the net you know.


..... Phil

 

[William Sommerwerck]

I made a mistake -- for some reason I assumed this was a tube amp. (I don't
know why.)

Regardless, if the output levels are closely matched, one amp /will not/
pump current into the other. But to gain any increase in power, you'd have
to use a lower-impedance speaker.

There is also the possibility that, even with the levels matched, the amps
might not "like" looking at each other.

"Buy a decent amplifier that delivers the power you need." -- The Lady from
Philadelphia

 

[William Sommerwerck]

Regardless, if the output levels are closely matched, one amp /will

You are VERY WRONG on this.

Why? You haven't changed the output voltage. If the amps are solid state,
their source impedance is much lower than that of the load, so there
wouldn't be any significant increase in current flow (that I know).

 

[Allodoxaphobia]

On Wed, 21 Jul 2010 18:53:58 -0700, William Sommerwerck wrote:

Assuming that both channels have the same output impedance, and the output
levels are closely matched,

.. and, assuming both outputs are _exactly_ in phase,

then (if the outputs are directly paralleled)
there will be /no/ current flow from one channel into the other, ....

Jonesy

 

[GregS]

Hi,
I have a small stereo amplifier which came with two tiny 4ohm 3watt speakers.
I'd like to combine the two channels of the amp in order to drive one, slightly

larger, 8ohm 4watt speaker.
The amp is of the non-bridgeable type, so I assume parallel wiring would be
required - combining the two outputs together. I have read that small resistors

are required in parallel configuration, to enable proper current sharing
between
the amplifiers, as without them the two amps would fight each other and
overheat. Can anyone tell me the correct values for these resistors, and where
they should be placed?

thanks,
jamie.

You forgot to give the power.

From quick reading of posts, to get more sound you can put 2- 8 ohm
speakers in parallel which will give 6 db increase over one
8 ohm.

You can bridge, say put 1-2 ohm resistors in series
with the speaker and use a bridge transformer on the input.
If you gave the minimum ohm spec of the amp, I could be more specific.
You also did not specify the output
type if the amplifier. Are the channels allready bridged ?

greg

 

[Phil Allison]

"Greg Shithead"

You forgot to give the power.

** It in the very first line of the original post.

You pathetic imbecile.



.... Phil

 

[GregS]

"Greg Shithead"



** It in the very first line of the original post.

You pathetic imbecile.



.... Phil

Reading.........

I have a small stereo amplifier which came with two tiny 4ohm 3watt speakers

Still reading.........................................

How tiny?

What color ??

greg

 

[Phil Allison]

"Greg the trolling Shithead"

I have a small stereo amplifier which came with two tiny 4ohm 3watt
speakers

** Wot a pathetic moron....




.... Phil