OSSC 1.6 – Dreamcast VGA cable Audio Hum

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This topic contains 13 replies, has 4 voices, and was last updated by  cheeseman 10 months, 2 weeks ago.

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    Hi there,

    Just picked up the OSSC – love it. everything I have thrown at it is working fine, but I’ve having a strange issue when using the Dreamcast with a VGA cable w/RCA outs

    The setup is really simple It goes Dreamcast NTSC Rev1 -> VGA cable with RCA outputs -> OSSC 1.6 firmware 0.79 -aud -> HDMI cable to samung tv.

    When using an RCA to 3.55 Stereo adapter cable to connect the VGA RCA plugs to AV3 on the OSSC (so it will push the audio into the HDMI out), I get this weird noise that is always coming out of the tv speakers. It sounds like Apu from the Simpsons when he worked 4 shifts straright and thought he was a hummingbird. (google it – I can’t describe it any better)

    It starts on the system menu of the Dreamcast, and it will always play. I found an option in the OSSC called “audio downsampling” if I change it from 2X to off, the noise stops, but then I also don’t get any sound.

    If I route the RCA jacks to a receiver, it sounds fine through separate speakers.

    Maybe it’s the cable? ( Or maybe I shouldn’t be using the -aud firmware, but I think that’s how you pass sound through the HDMI out.

    Just wondering if anyone else had experienced this or if I was missing something simple.

    Thanks in advance – if I left out any important info let me know and I will get it.



    Sorry for that massive first post – but figured the more info the better 😛

    Just a quick update on this – I tried plugging in an old laptop via VGA with a 3.55 from the headphone jack to AV3 in and….

    No Apu humming bird sounds. 🙂

    I’m guessing it was just the VGA cable – still I would be interested to hear any suggestions. (I’m still new to the OSSC, might of missed something simple)

    Also, I have a ton of other retro consoles w/scart cables from if anybody would like me to test anything 🙂



    Seems to be the cable. The audio is interfering with the video signal. When you use cheap scart cables, you often have the same problem. Let me guess, the noise changes with the color on screen?

    Just forget about these crappy VGA cables and get a VGA Box. You will need a 15/31khz switch anyway.



    The general rule of thumb seems to be that straight VGA cables for the Dreamcast are crap, especially the Tomee ones; I haven’t heard of any of these mass-produced cables being of quality.

    That said, if you don’t want to go the VGA box route, quality straight VGA cables do seem to exist. People on the shmups forum have reported that thefoo83 on eBay makes quality cables. If they don’t currently have any listings for the cable you want, you can message them.



    @ SegaFanboy – oddly enough, the color doesn’t affect the humming sound. But you are correct in the sense that the audio/video/quality of this cable is all over the map lol

    I will say that this cable does look great for the price – but you must route the RCA jacks elsewhere or deal with a really high pitched hum.

    I’ve actually ordered a Toro, and it should be shipping out soon and arriving in a few weeks.

    Really liking the OSSC, I feel like I am not even using it to its full abilities.. The Sega and Nintendo consoles I plug into it are rocking just using the default settings.

    Thanks guys, appreciated.



    Was going to start a new thread, but figured it might be worth including the history here:

    Toro showed up – looks fantastic paired with the OSSC 1.6, but again having weird audio issues.

    When I use a standard VGA cable and a RCA to 3.55 from the Toro to the OSSC – The sound will randomly start sounding weird then cut out.

    This occurs on any game and seems random. The video never stops/freezes and the sound will eventually come back. Doesn’t matter if you are just chilling on the menu screen, or there is a ton of action on the screen. Weird.

    But, if i bypass the OSSC completely and go to my receiver it’s fine. I’m still on firmware .79 (-aud with the option to pass audio through HDMI out)

    Before it was the cheapo VGA/RCA cable 100%, but now i’m thinking it might be that audio port not playing nice with the toro, or maybe I shouldn’t be using the -aud firmware?

    Any thoughts on this one?

    As always, thanks in advance.



    You won’t get any audio if you don’t use the -aud firmware.

    Are you having audio issues with any other system?



    Hi BuckoA51,

    Sadly I don’t have anything else to test with VGA and the AV3 input. (Like the dreamcast)

    I have the SNES running right now through a good scart from retrogamingcables UK into AV1 and it does still randomly cut out.

    In the last 30 min of running it, it has only cut out once, for about 5 seconds them slowly came back.

    I’m just using the default settings on AV1./



    Your SNES’ picture cut out, or the audio? SNES is a troublesome one though, so it’s hard to draw any conclusions from that.



    -Bad wording on my part = It’s just the sound. No issues with video what so ever on any console I have tested so far.

    It’s really random. Yoshi’s island was cutting out randomly during the main menu/credits, then after about an hour of troubleshooting I couldn’t reproduce it.

    I’ll plug in the Sega Model 1 today and play around with the mono out and Stereo out to see if I can reproduce.

    Heck I guess I could just plug in a CD player into the OSSC and let it run to see if it cuts out as well.



    Yep Megadrive should be a good test, if that has issues too I think it will be best to RMA your OSSC.



    Thanks Bucko,

    I ran my Sega Model 1 all day (passing the audio into the OSSC via the 3.55 stereo jack) and couldn’t get the audio to cut out.

    I’m going to run though all the other consoles I have and try to narrow it down… maybe it was something silly like bad cables or bad connection. Just curious what is the RMA process if I do figure out the issue is OSSC related.

    Also, is there a way to shift the image position using the OSSC? I am finding that the image is always just a bit off to the right.



    Just e-mail in via the contact form to arrange RMAs.

    You can use the H.Backporch setting in the advanced timings menu to shift the image.



    Email sent for RMA.

    Just got my sega saturn working again (laser died) was playing with a scart cable from retrogamingcables and BAM, audio cut out again, came back in 2 min just like my SNES and sega’s.

    I figure at this point it’s just best to RMA it before it gets worse or stops working all together.

    To anyone reading this don’t let it discourage you from grabbing an OSSC – I really just want mine refurbished/replaced because I stick by the OSSC for my retro gaming setups 🙂


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