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Sound Blaster/ Adlib sound over internal speaker?

RadRacer203

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I'm starting to put together parts for my 5155 and I was just curious if it was possible or feasible to have the sound card output to the internal speaker? It would be nice to have that contained so I wouldn't need to carry around speakers or headphones for it. I have a Sound Blaster 1.5 I was planning on using but I'm not set on that. If there's a model that would work better for this I'm open to it.
 
If you have a cd audio or line-in header on your sound card, you could run the pc speaker output through a pot (to adjust so you don't overdrive the input) and into the cd audio or line-in header. Then hook the pc speaker up to the speaker output on the card. The would give you a way to adjust the levels in software.

Barring this, you could probably just wire the positive side of the PC speaker and the left and right outputs of the sound card all together with resistors in-line, maybe 10k (or pots, if you want to be able to adjust the audio balance), and then run all that through the PC speaker. This is the route I plan to take when I eventually put an ad-lib in my Tandy 1000HX.
 
IThis is the route I plan to take when I eventually put an ad-lib in my Tandy 1000HX.

The 1000 HX actually has a line on the expansion bus, B08, that leads to the onboard audio amp that the timer-based PC speaker output and the TI sound chip are mixed in. In principle if you laid out your own Adlib plus card you could route the audio directly through that, no jumpering.
 
The 1000 HX actually has a line on the expansion bus, B08, that leads to the onboard audio amp that the timer-based PC speaker output and the TI sound chip are mixed in. In principle if you laid out your own Adlib plus card you could route the audio directly through that, no jumpering.

Oh my. That is good to know, as building my own was exactly the plan. =:3
 
It actually got me thinking about it; it looks like they’re pretty simple and maybe I could compress it even more by practicing my GAL programming skills. Must build other things first...
 
If you have a cd audio or line-in header on your sound card, you could run the pc speaker output through a pot (to adjust so you don't overdrive the input) and into the cd audio or line-in header. Then hook the pc speaker up to the speaker output on the card. The would give you a way to adjust the levels in software.

Barring this, you could probably just wire the positive side of the PC speaker and the left and right outputs of the sound card all together with resistors in-line, maybe 10k (or pots, if you want to be able to adjust the audio balance), and then run all that through the PC speaker. This is the route I plan to take when I eventually put an ad-lib in my Tandy 1000HX.

Thanks for the suggestions. I do have an Aztech Sound Blaster clone card with a cd audio connector. I think I may try that first idea, is the cd audio just a passthrough to the speaker output essentially? Or will I have to set in software for it to do that?
 
I thought about doing this with my 1000RL/HD. Would be fun to hear OPL2 tunes coming out of the PC speaker...and the case would help filter some of the junk out of the original SB DAC output!
 
Thanks for the suggestions. I do have an Aztech Sound Blaster clone card with a cd audio connector. I think I may try that first idea, is the cd audio just a passthrough to the speaker output essentially? Or will I have to set in software for it to do that?

Most cards with a cd audio header allow for the volume to be set in software. So it's not a *straight* passthrough, but yeah. It goes into the cd audio header, through the onboard mixer (cd volume), through the output amplifier (master volume), and into the speaker.

Note though that the line level that the cd audio header will be expecting is probably 2 or 3 volts iirc. I wouldn't be surprised if the pc speaker clicks on 5 volts. So you'll probably need some value of resistor in there to keep from overdriving the input on the sound card. A pot would be easiest.
 
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