SNES Mini audio buzzing

I’ve recently discovered a buzzing noise coming through the audio outputs on my SNES Mini and it’s driving me nuts.

My 2 older SNES consoles are quiet using the same cable and same power supply. Here’s what I’ve tried:

Built my own shielded cable from a VGA cable.
Removed DIY RGB amp and wired right from the video chip itself
Run audio lines separately from the multi out. I have not tried to run it right off the chip itself.
Recapped console
Replaced 7805 Voltage Regulator

Anyone have any other ideas? I’m at a loss here. It’s extremely noticeable on the SD2SNES menu screen and barely noticeable during gameplay but it does happen with legit carts as well.

Do you still have interference when using an AV cable (yellow red white)? With the mod installed.

The buzzing persists over a regular composite cable as well even without the mod installed!

Sounds like it’s time to install the optical audio output mod! Absolute crystal clear audio, digitally sourced from the SPC.

That kind of buzzing is usually from the Composite Video leaking into the audio wires. AV cables are using coax and shouldn’t be subject to it, it must come from the console itself.

Are you willing to experiment?

What I would do is nip the composite signal as soon as it comes out of the chip. Looking online, it should be pin15 of the chip S-RGB A BA6596E. make sure it’s the correct one by testing the continuity, and lift the pin or cut the trace next to it. Or maybe there’s a jumper not far away. If you still have interferences, then I’m at a loss as to what could cause it.

If you want to keep a Composite out, you could restore it by having a wire from the pin to the connector. A simple wire should be enough, but you could be extra careful and use a bit of coax.

I’d prefer to keep this SNES fully analog. If I’m going to go digital sound I’d rather just get the Super Nt.

That said putting a 220uf capacitor on the 7805 made a noticeable improvement to the buzzing. It’s still there but it’s virtually unnoticeable during game play. I’d love to finally eliminate it once and for all though!

Socks, have you checked the inside of the system for these guys?

Seriously though, glad to hear you’re making progress and that a 220uf cap has reduced it. I can relate, I was going mental with the buzzing coming from my GBA until I installed a cap to soak up all that low frequency.

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I’m going to leave it for now but when I get a chance I’ll give this a shot. I have no interest in keeping composite around so it’s a no brainer to get rid of it.

That’s exactly what it was. I’m so glad you gave me the heads up.

Here’s where I’m at after installing the capacitor.