No. It can output only 40mA. That is 9 mW RMS into an 8 Ohm speaker.

Please erase the idea of impedance matching for audio. The best output impedance for driving speakers is zero. Good power amps are well under an Ohm.

Also, open loop output impedance is the wrong figure to use since you cannot use it open loop. The output impedance with negative feedback will depend on the gain but be much much lower. Like thousands of times lower typically.

what do you recommend?

 

There are op-amps intended for "Line Level" outputs, which are actuallu0.7 volts for a "zero VU" signal, which is a standard often follower rather loosely.
And 9mW may or not provide an adequate listening level. The original amplifier is fine for driving a speaker and headphones by them selves.

 

I would use an op amp such as TL074 to firstly buffer the Left and Right line level signals.
Then take the difference and sum for (1) and (3) respectively.
You cannot obtain (2).

You have three variables but only two equations. You cannot solve for all variables.

Please explain why I cannot have (2).
I am first using a diff amp to remove what is common (hopefully voice). Then I use a second diff amp inputing the output of the first with a mono signal (L+R) from a third op amp. (All are MC33171N.)
It shouldm't matter which side is inverted; the result should be the difference which, at this point, is voice alone, no?

 

If you are trying to create a surround sound effect, there are some schemes you can try.

Take the sum signal and feed it into a low-pass filter with a cut-off frequency at 200 Hz. You can feed this into a center-channel sub-woofer.

You can take this filtered signal and subtract it from the original Left and Right channels. This will hopefully remove the common signals below 200 Hz. These can be used to drive frontal left and right amplifier/speaker.

The problem with filter circuits is that they will introduce phase distortion.

thank you, but that's not what I'm hoping to get.

 

for the most part I am not.

Yes, I read" "The PAM8403 sets maximum RF =142kΩ, minimum R =18kΩ, so the maximum closed-gain is 24dB" in the spec.
But the unit is a commercial module that incorporates the 8403. I have to assume that they got that part right.

 

The TS has stated quite clearly, most recently in post #103, that the intent is to separate the vocal track from the music tracks. Exactly the opposite of creating a center channel.

 

The TS has stated quite clearly, most recently in post #103, that the intent is to separate the vocal track from the music tracks. Exactly the opposite of creating a center channel.

Yes, but that's the first part. A "center channel" is the product of IC3 which when input into IC2 along with the output of IC1 should yield only voice (and possibly bass).
I want all three possibilities.