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Sega C2 stereo mod ?

Fredo

Fredo

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Would that be possible ?

"Audio output

The left channel output of the YM3438 is connected to the rest of the audio
mixing and amplification circuitry, the right channel output pin is
unconnected. So even though a stereo sound chip is used, only mono output
is available."

https://segaretro.org/Sega_System_C2_hardware_notes_(2003)

The right channel output of the YM3438 chip is unconnected. But is there anything coming out of it that could somehow be used to get stereo sound, like on a MegaDrive?

Makes me wonder if the games are coded just as their MD counterparts, or are they mono in software?

Sorry I don't know much about how these kind of things work.

Thanks.
 
Put a audio probe on pin 20 to hear if it's outputting anything.
 
If there was true stereo sound coming out of the right channel, wouldn't they have mixed it with the left channel? So you would have all the sounds on the mono output? If not, would there be missing sounds?
 
Derick2k said:
If there was true stereo sound coming out of the right channel, wouldn't they have mixed it with the left channel? So you would have all the sounds on the mono output? If not, would there be missing sounds?
Click to expand...
Could be a dip or jumper change?
 
I'd suspect it's one of 3 scenarios
1. the second channel is completely unused (meaning it's mono)
2. the second channel is identical to the first (meaning it's mono)
3. some sounds are processed on one channel and other sounds are on the other channel and are mixed down stream (meaning it's not actually stereo and would sound crap if you left them separated).

While not impossible it seems unlikely that they would have gone through the effort to stereo mix the games for hardware that didn't support it.
Then again the C2 is essentially a Sega Genesis, which did support stereo so maybe there's something there ¯\_(ツ)_/¯
 
twistedsymphony said:
I'd suspect it's one of 3 scenarios
1. the second channel is completely unused (meaning it's mono)
2. the second channel is identical to the first (meaning it's mono)
3. some sounds are processed on one channel and other sounds are on the other channel and are mixed down stream (meaning it's not actually stereo and would sound crap if you left them separated).

While not impossible it seems unlikely that they would have gone through the effort to stereo mix the games for hardware that didn't support it.
Then again the C2 is essentially a Sega Genesis, which did support stereo so maybe there's something there ¯\_(ツ)_/¯
Click to expand...
#2 is correct. All games in C/C2 are outputting pure mono audio. YM3438 panning registers are all set to center.

#3 is not the case because only one output is connected. The audio mixing circuit does not provision for stereo mixing either so it would be impossible to do the mod without an external board.

However, should anyone do such a mod (i.e.: using a MegaAmp), there could be improvements to the audio quality since the audio is heavily filtered on System C/C2, much as it is on most other boards.
 
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