PC-engine Composite video issue.

[Pent]

So I was lucky enough to recently visit Japan and while I was there I managed to pick up a PC-Engine and controller at a good price. Now being in Europe and the PCE being RF only wasn't going to work out well for me so I decided to purchase a Tennokoe2 to use to get some usable audio/video. Using this diagram as reference https://gamesx.com/misctech/pcebp.php I wired up a composite video port to A22 and took the ground from A21, for the Audio I took Left from A1 and Right from C1 and took the ground for both from C2.

In this situation the audio is far too quiet but the composite video output is surprisingly good. Audio amps are cheap and easy to source so I bought the following item from ebay https://www.ebay.co.uk/itm/2-5-10PCS-2- ... 2338405866 I wired it in using +5v from C21 and pulled the Ground from C20. The audio level is now a lot better but I don't get a picture. If I remove the audio cables from the TV then the picture will show but as soon as I connect an audio connector it's seems like the video sync gets messed up.

Can anyone point me at what I might be missing here?

[Kez]

Perhaps the amp is drawing too much power.

[nmalinoski]

Since you're in Europe, where RGB and SCART aren't unusual, why not use those? RGB boards for TG15/PCE are readily available*, as are the SCART cables, and retrostuff.org has a guide on modifying the Tennokoe 2 for RGB output.


* These are unfortunately outside of Europe; I checked VGP, which is in UK, but they don't seem to have any. :<

[Kez]

AV Driver does seem like your best best, as it specifically addresses the audio issues with earlier TG16/PCE models.

Although SCART and RGB used to be common here, that is not really the case anymore. That said if you do have a way to use RGB, I agree that since you are modding the Tennekoe anyway might as well go the whole hog and do a full RGB mod.

[nmalinoski]

Although SCART and RGB used to be common here, that is not really the case anymore.

Great. Now I want an OSSC with 5x BNC inputs instead of SCART.

[Kez]

Great. Now I want an OSSC with 5x BNC inputs instead of SCART.

Haha, I just mean the average household is less likely to have SCART capable devices these days. A lot of retro gamers run composite into modern TVs. If OP had an OSSC I'm sure they wouldn't have done a composite mod in the first place.

[thebigcheese]

Alternatively, if you can get your hands on a dB Grafx Booster, you'll get composite, s-video, and RGB options, all properly amplified.

[maxtherabbit]

Although SCART and RGB used to be common here, that is not really the case anymore.

Great. Now I want an OSSC with 5x BNC inputs instead of SCART.

YES

[Pent]

Thanks for the answers guys.

So part of what's going on here is that while I could just buy 'something' to get what I need I'm also using this as a general learning process and I enjoy the build / tinkering aspect of these mods.

RGB - this is the end goal, I have PCB's on order to build an RGB amp. Composite was an easy way to get it up and running to check the unit worked (it does) and the only thing stopping me from playing was the audio. At 99cents/pence/bottlecaps for 2 those audio amps are cheaper than I could get just the PCB for hence me going in that direction. I did a little more testing last night and it seems that it's some kind of ground loop. The TV I'm using has common ground across the 3 RCA jacks and if I put the sound directly into some headphones everything is just fine but as soon as I connect an audio jack to the TV I lose the picture.