MiSTer FPGA Forum

Greetings! It's my first time posting here, but I am a long -time MiSTer user and have found this community helpful many times. I'm just not much of an online-forums-posting guy.

Today though, there is an audio issue that I am having difficulty troubleshooting that I'm hoping someone may be able to help with.

I originally put my MiSTer together back in 2019 so I have an analogue I/O board. I recently came across an inexpensive old CRT TV that has component and composite (no S-video) so I picked it up to use with the MiSTer. I first used VGA to component and 3.5 mini to RCA via the analogue I/O board and noticed that there is no right audio channel. I confirmed it wasn't the TV or cables by trying different cables, speakers and headphones. I couldn't find any setting that might affect this so I ended up picking up a super-cheap $5 DAC and used the mini-TOSlink instead.

This fixed the problem and actually sounded pretty good, at least on the old TV speakers. At this point, I figured I probably have some fault in the analogue I/O board remembering that I got it from a random eBay seller.

Today, I am planning on reviving my old PS2 to use with the component input on the TV so I was testing moving the MiSTer over to composite using the Y/C active encoder board. I am also considering replacing the analogue I/O board with the digital I/O so I can have a dual SDRAM setup.

With that in mind, I wanted to test direct video instead of the analogue I/O VGA and found another super-cheap converter to change HDMI to VGA that also has an audio output.

The quality might be questionable, but I like that it allows for a pretty clean setup as far as cables since I can plug it directly into the Y/C active encoder board. Also, at the price, it was worth a try.

It actually works, but once again, there is no right channel audio! If I set stereo mix to 100% on cores that have the setting (e.g. SNES) I get the right and left channel mixed in both speakers. I realize this isn't a big problem and I could just use the DAC, or use mono audio out of the TV, but I'm the type of person who will end up wasting a lot of time trying to find the solution I am looking for. I am hoping someone here might be able to provide some insight.

TL;DR: No right channel audio from analogue I/O board or HDMI. Analogue I/O mini-TOSlink through a DAC works perfectly, but I am changing to a setup where I would prefer to use audio through HDMI.

Have you tested The HDMI audio with the analog I/O board removed?

I have not, but that is a good idea. I'll give it a try this evening (Korea time).

Update - the problem is still there with the analogue I/O board removed.

I should make certain it isn't the cheap HDMI > VGA adapter I have, so I'll try hooking it up to an HDTV tonight. I'll also try plugging the converter into something else to see if I get both audio channels. I have an old Raspberry Pi 4 somewhere, so that should work.

I appreciate any more advice that helps me solve this.

I could be barking up the wrong tree here but it might be worth checking your ini settings.
You can change the output quality of the HDMI audio I believe.
Try setting it to a lower quality and see if it improves.

I don't actually expect this to work seeing as you do get audio from 1 channel but it's something that popped into my mind so thought I'd share

So I was never able to figure this out. I tried normal HDMI output on an HDTV where both audio channels worked fine, but I don't have another device I can hook up to the HDMI > VGA adapter to rule it out. I should have a raspberry pi 4 somewhere but I can't find it. It doesn't really matter if it is the adapter though since I also found that it does not play nice with certain cores (most notably Genesis and Turbo Grafx). For now, I'll try to find a different adapter that works with all cores and stick with using the DAC for audio.

Finally, just to be sure it wasn't a setting somewhere, I did completely wiped and rebuilt the SD card, reinstalling everything.