December 12, 2017 at 1:39 AM #17959
I tapped the Mega Drive’s audio before the amp and routed it to the headphone jack; the distortion is gone.
I recommend doing that anyway unless you plan on using headphones with the Mega Drive, since the audio has less noise.
I’m not familiar with model 2s, but if they do output line level stereo through the minidin I don’t see why they would have an issue with distortion.December 12, 2017 at 9:50 AM #17963
Is it possible to decrease gain on the AV1 input?December 12, 2017 at 6:22 PM #17969
@zoomer88: yes, I’m aware that Model 1 DIN audio output is mono, but didn’t know that many available rgb cables were wired to use headphone output which is not a good idea in general. There’s no point in installing audio mod for v1.6 board, but you may try adding a simple lpf filter or just a load resistor on the scart block.
@jonlad: audio (pre-adc) gain adjustment is on the list of upcoming features, but it is primarily meant for balancing audio level between sources/profiles and probably won’t help here as you can already adjust the level of headphone output – right?December 12, 2017 at 7:27 PM #17970
I’d bet Retro Gaming Cables and Retro Console Accessories sell more cables that use the headphone output for audio than without. The fully shielded cable from RGC isn’t even available without it.December 12, 2017 at 7:39 PM #17971
@gummi True that
@marqs Soldering iron for me is like a gdi ion canon. No way I’m gonna touch that black magic sorcery. But you are correct – lowering Genesis volume slider doesn’t eliminate the distortion unfortunately. What’s intersting is is that only OSSC exhibits this issue. No other appliance has problem with such a signal (several different TVs from sony and lg as well as Yamaha and Denon AVRs – all have no problems with it.
Not to mention that said output is near perfect on my console – no noticeable interferences (well, aside from that VDP noise, but it’s picked up way earlier afaik and no amount of audio circuitry bypass will help to avoid it. Even so, it’s really faint, almost negligible).December 13, 2017 at 12:15 PM #17978
So our only option is to mod the MD or mod the cable, which works fine with any other device?December 13, 2017 at 9:10 PM #17990
Or add the antialias filter on ossc board, which apparently works fine with any other console as is 🙂December 27, 2017 at 3:59 PM #18187
I experience the same issue. Digital artifacts/distortion (high pitch chirping) of the audio signal.
RetroGamingCables headphone out scart cable.
Sega Mega Drive VA1 NTSC-J
Scart to TV is fine. Scart to OSSC is horrible.
This is disappointing since this is my most used console.December 29, 2017 at 2:58 PM #18226
Does anyone have a real solution to this problem? It must be a widespread problem since headphone out scart cables are pretty much the de-facto standard.
“try adding a simple lpf filter or just a load resistor on the scart block” How is this achieved?
“add the antialias filter on ossc board” How is this achieved?
“I tapped the Mega Drive’s audio before the amp and routed it to the headphone jack” How is this achieved?
These are not really solutions or understandable for people that are not electronics experts. Are any of these guaranteed to fix the audio?
Would the MegaAmp2 and a mini jack line out on the rear of the console fix this problem?
ThanksDecember 31, 2017 at 1:11 AM #18261
I’m guessing the reply by Marqs above is our real solution.December 31, 2017 at 12:09 PM #18264
I’ll keep looking into this for a definitive answer!January 1, 2018 at 2:22 AM #18282
That’s awesome. Cheers.
Just wondering. Are you involved officially with OSSC?January 1, 2018 at 11:45 AM #18286
Yes, I’m the website owner 🙂January 3, 2018 at 9:40 PM #18331
Has anyone tried a 3.5mm Y-splitter adapter/cable to connect headphones simultaneously? I wonder if that CXA1034 headphone amp just needs low-impedance load to behave properly.January 5, 2018 at 5:30 PM #18360
I’ve managed to confirm this here with a Megadrive 1 and stereo SCART cable. Affects 1.6, doesn’t affect 1.5.
You must be logged in to reply to this topic.