MiSTer FPGA Forum

Today I connected my MiSTer to a Dell 2001FP 4:3 LCD via HDMI to DVI adapter and the latest ini file intended for the 2007FP. Every core works flawlessly.

The problem arises when I connect the Dell's soundbar 3.5mm cord to my analog A/V board output. When I do that, the screen image (and my MiSTer) freezes. The only fix is to power off and reconnect my MiSTer to my main display (an OLED TV) and my Main ini file. I can then re-connect it to the Dell 2001FP and switch to the appropriate ini, and all works well again -- unless I attempt to connect the analog audio.

I know my analog audio works as I occasionally connect to a CRT TV with audio.

This has me stumped!

I think there is a jack for like ADC data in (something commodore tape players used) on some mister builds, it looks like a headphone jack but isnt.

https://github.com/MiSTer-devel/Wiki_Mi ... ape-input)

Not saying this is your issue, but Im not familiar with your setup. There are many variations.

Some ideas for narrowing down the problem:

• Is DVI mode enabled in the ini file?

  Code: Select all

  ; set to 1 for DVI mode. Audio won't be transmitted through HDMI in DVI mode.
  dvi_mode=1
  

• Have you tried connecting another audio device such as head phones?
• Have you tried using the Dell soundbar together with your main display (with DVI mode enabled)?

12characters wrote: ↑Wed Feb 01, 2023 4:10 pm

Some ideas for narrowing down the problem:

• Is DVI mode enabled in the ini file?

  Code: Select all

  ; set to 1 for DVI mode. Audio won't be transmitted through HDMI in DVI mode.
  dvi_mode=1
  

• Have you tried connecting another audio device such as head phones?
• Have you tried using the Dell soundbar together with your main display (with DVI mode enabled)?

#1 yes
#2 and 3 - no; will try now

That sounds like an electrical problem, like something is wrong with the analog board. You might want to contact your seller for support.

A way around the problem, assuming that the soundbar can take a Toslink input, would be to run a Mini-toslink to Toslink adapter, making sure it's fiber only, no copper. Digital sound on the Mister is much better than analog anyway, so you'll get better reproduction.

But that's hiding what sounds like an underlying problem, instead of fixing it.

From reading another thread, the thought occurs that it might involve the CEC signaling on the HDMI port, which AFAIK isn't defeated by DVI mode. (this could be wrong, however.) The Mister and CEC do not get along well.

I ordered one of these: https://www.amazon.com/dp/B07BFL8TM8

and it's been working. It's just a passthrough adapter that doesn't connect pin 13. It's $15, which is a little overpriced, but it can be a very handy gizmo to stick on the Mister's HDMI port.

Malor wrote: ↑Wed Feb 01, 2023 11:25 pm

That sounds like an electrical problem, like something is wrong with the analog board. You might want to contact your seller for support.

A way around the problem, assuming that the soundbar can take a Toslink input, would be to run a Mini-toslink to Toslink adapter, making sure it's fiber only, no copper. Digital sound on the Mister is much better than analog anyway, so you'll get better reproduction.

But that's hiding what sounds like an underlying problem, instead of fixing it.

This is a strange one!

Building on the toslink suggestion, I had another idea to work around this problem, since, to my knowledge, those early Dell soundbars do not have digital inputs, only analog 3.5mm stereo input.

You could obtain digital audio from a supported I/O board (or using a device to extract from the HDMI signal before the DVI conversion) and pass it through a cheap (~$15) DAC and out to the sound bar. This should isolate any analog circuitry out of the MiSTer and still get you audio.

Example: https://www.amazon.com/Digital-Converte ... 09ZHPX2BR/

Note, some HDMI extractors will do this deed as well.

https://www.amazon.com/Flashmen-Extract ... 09JNR9D6H/

You would use a standard HDMI cable to one of these devices, use its analog audio output to feed into your soundbar, and then connect your hdmi to dvi connector to on the output of the extractor.

One other thing to check/ask... How is the soundbar powered? Some of these speakers can be powered from the monitor directly, some can be powered by a separate 12v supply. Have your tried both wiring configurations?

I've been using a dell sound bar for ages and have had no issue, apart from lack of bass on the speaker but it worked ok with mister. Not sure its the same version you have though.

Update: I tried a bunch of combinations and they all work:
HDMI video with headphones connected to analog out
HDMI video with external DAC connected via 3.5mm TOSLINK digital adapter and headphones plugged into DAC
DVI Video (sound disabled in INI via the Dell 2007FP ini file) with headphones plugged into analog out

So the variable seems to be my particular old Dell AS500 soundbar. When I plug that sucker into my Analog out the Mister freezes. I am afraid to try it again! Not the end of the world as every other audio option seems to work.

Also, for the record the update 2007FP ini floating out there is great and works on the 2001FP also! I have both.

Thank you for the suggestions!

I'd definitely try a CEC stripper. They aren't that expensive, and it's just good practice to put one on the Mister, because it plays hell on that control bus.