Sega Dreamcast HKT-8100 VGA adapter - mono only?

I recently received an official Sega Dreamcast VGA Box. The HKT-8100. It has a VGA output with 3.5mm headphone jack, composite and S-video with RCA stereo audio, and a little switch to select switch between VGA mode and AV/S-video mode.

In my setup, the VGA side of the box outputs to a little VGA to HDMI upscaler and while the S-video goes to an S-video to HDMI upscaler. I also split the RCA audio and send the composite video to a CRT for light gun games. Both upscalers go into a HDMI switchbox with all my other video converters, which in turn goes into a second switchbox with all my HDMI consoles, which outputs to my Elgato Game Capture HD which goes into my HDTV.

I went with the official Dreamcast VGA box rather than the cheaper third party alternatives, simply because I've had too many bad experiences with aftermarket AV cables. Quality wise, the VGA looks amazing on the Dreamcast. S-video looks fine, not as good as the VGA but it'll do. And the composite looks good on my CRT.

However, I was doing some game capture tests last night and I found that in VGA mode the box was only outputting mono through it's 3.5mm jack. The RCA audio outputs stereo, but only works in the S-video mode. I even plugged a simple 3.5mm to RCA adapter into the port and tried feeding stereo into the Analog AV port on my Elgato with RCA cables. But the same thing happened. Mono only.

I've contacted the seller on ebay who sold me the adapter. She assured me it was in full working order when she sent it, and asked me to send it back to Japan so she can double check. Does anyone else have the official Dreamcast HKT-8100 VGA box? Can you confirm if the unit is supposed to only output mono in VGA mode or is the stereo my unit broken?

Attached are some photos of my setup.

 

I have the same one. The RCA outputs work perfectly fine when set to VGA on mine, and is stereo for sure. Haven't tried the 3.5mm jack. Sounds like something is wrong with yours

 

Interesting. Can you give the 3.5mm jack a test and see if it supports mono or stereo? Thanks.

 

OK, thanks for the tip Bearking, I just did another test with the VGA box. This time feeding to audio to the HDMI converter from the RCA ports. That worked and I got my stereo sound. In my previous tests I had both my HDTV and CRT on when running the Dreamcast in either VGA or AV/S-video mode. In VGA mode, my CRT wasn't receiving video OR audio. So I assumed the RCA audio ports didn't work in VGA mode, looks like they do after all.

I don't understand why the 3.5mm jack is only outputting mono though. The port is clearly labelled "Stereo Audio". Must either be a false advertisment or the stereo on the 3.5mm is broken. Either way, the RCA audio output should be an easy enough fix. I'll just need to get another RCA splitter cable. Thanks.

 

Have you verified that your 3.5mm jack cable works fine on other devices? I don't have one handy so I can't test now.

This thing was made for PC monitors and stereo PC-speakers, so I would be very surprised if it didn't support stereo audio on the mini jack-port.

 

I'm using a brand new Digitech 3.5mm to 3.5mm cable that I purchased from Jaycar Electronics literally three days ago. There's definitely nothing wrong with the cable. I plugged it into the 3.5mm audio out on my SCART switcher and was able to get stereo sound out of it without issue. And as I stated above, I also tried a 3.5mm to stereo RCA adapter with RCA cables feeding into the analog AV input on my Elgato, the same thing happened. My HKT-8100 simply won't output stereo through it's 3.5mm jack.

 

Dry solder jonit on the vga box ??

 

Possibly. Unfortunately, I don't have any soldering skills nor soldering tools required to do any repairs.

 

The official vga box does support stereo audio on the 3.5mm, In my config I use a couple of usb-powered logitech speakers and the 2D fighting games sound properly when a character is at one border of the screen or the other, in one party I even played blindfolded once because of that.

Perhaps you could contact someone with a workshop to do some testing first, maybe it's an easy fix.

 

I could take a look at it for you if you want.