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GameSX.com => Audio Mods => Topic started by: raisinland on July 30, 2007, 10:47:19 AM

Title: Dreamcast Digital Audio on the wiki
Post by: raisinland on July 30, 2007, 10:47:19 AM
Hello all. I just added a digital audio mod for dreamcast under the "AV Mods" section. (There's a Saturn digital audio mod there as well). take a look!
-John
Title: Dreamcast Digital Audio on the wiki
Post by: NFG on July 30, 2007, 03:02:30 PM
I was halfway through a post detailing some of the excellent work you've been doing on the wiki lately when this popped up.

So, um, good work.  Keep it up.  =)
Title: Re: Dreamcast Digital Audio on the wiki
Post by: david656 on December 25, 2009, 02:29:49 AM
raisinland,

i have tried to follow your modification, however to no great success. can you please assist?

i have attached a copy of my PCB design, based on the VGA mod as well as your digital audio mod.

any help is greatly appreciated
Title: Re: Dreamcast Digital Audio on the wiki
Post by: SGGG2 on May 28, 2011, 07:00:31 AM
Hi,

I have all the needed parts listed in the wiki, but I'm lost at "inverting the signal"? I can follow directions and solder easily enough, but have little electrical knowledge. Can someone please help?
Title: Re: Dreamcast Digital Audio on the wiki
Post by: zyrobs on June 19, 2011, 06:24:04 AM
Quote from: SGGG2 on May 28, 2011, 07:00:31 AM
Hi,

I have all the needed parts listed in the wiki, but I'm lost at "inverting the signal"? I can follow directions and solder easily enough, but have little electrical knowledge. Can someone please help?

Pulling a pin low or high means applying 0V or +5v to it (you have to check the datasheets of the chip for exact values, though most chips work with +5v.).  One of the ICs turns emphasis on if it's pulled low (0v on the emph pin), the other turns emphasis on if it's pulled high (+5v on the emph pin). You need to invert the signal, so whenever chip A sends 0v, chip B receives +5v. You can use a hex inverter IC for this.

Or, you can measure the voltage of the emph pin with a multimeter and apply the inverted signal directly, since I doubt that the console actually changes emphasis during function. Meaning if the PCM1725 pin 12 measures 0v, you can just solder +5v to pin 3 of the cs8406.