How to add a 3.5mm Audio Jack for PC Speaker?

[icono]

I have a Laser Turbo XT with no sound card. I would like to build/buy a small circuit to allow me to connect a set of Amplified Stereo(working in mono) speakers to the PC speakers connection.
To give me volume control and a place to connect headphones. I know some Sound Blaster sound cards could connect to the PC speaker and mix it into the speaker output. With the cost of 8bit ISA sound cards these days it seem about bit of overkill. Does such a project already exist?.

 

[Plasma]

Here is the schematic for the Lo-Tech Tandy Sound Adapter which has optional PC speaker input.

 

[krebizfan]

If you don't want to add a card, maybe look at http://www.oldskool.org/guides/speakerrecording/#Alternate which shows how to pass the signal to an external stereo. The Laser Turbo XT may require some modifications to the design; I don't know that computer.

 

[deanimator]

A PC speaker is usually driven straight from TTL output of a timer, on PC, that is 8253 PIT channel 2.
A blocking capacitor in series with its output, and a voltage divider or trimpot, will usually be enough. That's exactly the schematic above.

 

[icono]

If you don't want to add a card, maybe look at http://www.oldskool.org/guides/speakerrecording/#Alternate which shows how to pass the signal to an external stereo. The Laser Turbo XT may require some modifications to the design; I don't know that computer.

Thanks for the link I might try a few of the designs and see how they work.
I moved the reset button from the back of the case to a blank 5 1/4 drive bay, I should be able to repurpose the hole in the back of the case to add the audio jack.