Sega Genesis audio crackle

[Sarge]

So y'all are probably familiar by now with my Genesis recap project. I figured I'd be able to get rid of the audio crackle (similar to the sound that you get on an old set of speakers when you adjust the volume) by recapping, but no dice. So any other ideas as to what might be going on? Could it be the chip itself? Or is there another component that would be worth changing out?

I'm pretty sure it's not the power supply, I've tried two different ones with the same result, and I've also used the same supplies on my other two Genesis consoles with no issues. The crackle also shows up on both the multi-out and the headphone jack, so it's something common to both those circuits.

[samsonlonghair]

Could you post a high-res photo of the genesis innards, please? We can always take a look and see if anything looks suspicious.

[Ziggy]

+1 to the pics suggestion.

What power adapter are you using to power the console? The reason I ask is that I once used a shitty power adapter (had the right specs - it was just a cheapo) with a HDG model 1 Genesis and got very bad audio. My memory is fading of what it sounded like, but I wouldn't use "crackling" to describe it. It sounded more like blown speakers. But at any rate, switching to a better brand power adapter completely fixed the problem.

[Sarge]

I'll see if I can't snap a pic when I get home.

They're both official Genesis power supplies. Used 'em for years with both the Sega Genesis and CD.

I'm not sure the right word is "crackle", either. It's kinda similar to the sound when you, say, hook up a set of headphones to an audio jack, a kind of staticky sound. It's not constant, though, there's a low level noise in the background, and every once in a while, it pops more loudly. Actually, it's more like a radio station that's right on the edge of a good signal, it's mostly okay, but with a low-level static sound that will pop every now and then.

[samsonlonghair]

+1 to the pics suggestion.

What power adapter are you using to power the console? The reason I ask is that I once used a shitty power adapter (had the right specs - it was just a cheapo) with a HDG model 1 Genesis and got very bad audio. My memory is fading of what it sounded like, but I wouldn't use "crackling" to describe it. It sounded more like blown speakers. But at any rate, switching to a better brand power adapter completely fixed the problem.

Sounds like you're describing "dirty power sound" which is an issue I run into during mobile DJing sometimes. I can usually trace it to a grounding issue. If the power supply is not grounded properly, it can cause a "dirty" sound in the speakers. High power speakers are more susceptible to this than low power speakers.

[Exhuminator]

I wonder if the Genesis shares a central DAC between all its audio components.

I'm trying to think of a central culprit.

[Sarge]

Maybe I should try reflowing the power connector, could be that it's developing an issue there?

[Ziggy]

I know you said the problem occurs in both the multi AV output and headphones output, but have you ruled out bad cables?

[Sarge]

Yeah, same cables work fine on my other Model 1s.

[Sarge]

Okay, here's some pics. Some aren't the best, but it might be enough. I'm not seeing anything that jumps out at me at first blush, but maybe y'all have better eyes for this than I do!

You can ignore the one trying to shoot under the heat sink, I decided to just go ahead and pull it off. That should be the last pic in the set.

http://imgur.com/a/WZW5d