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Scratchy sound on several cores

Posted: Fri Aug 23, 2024 5:38 pm
by NightShadowPT

Hi,

Since I last updated my MiSTer, I have been having problems with sound on several cores.

Usually happens on the bass notes and manifestates as heavy crackling.

I have tested it in the Amiga Core (with Oh No More Lemmings), the SNES Core (Chrono Trigger) and Playstation Core (Castlevania - Symphony of the Night) and they all display the same problem.

I have tested with multiple cables and speakers, with the same result, leading me to assume the problem is coming from the MiSTer itself.

Any ideas what this could be, and how I it can be addressed?

Thanks in advance


Re: Scratchy sound on several cores

Posted: Sat Aug 24, 2024 3:54 am
by rhester72

Tested pretty heavily with all the titles you mentioned and heard no issue with audio whatsoever.

What audio path are you using on MiSTer? I only have the capability to test HDMI here - if you're using optical, that's a whole other ball of wax.


Re: Scratchy sound on several cores

Posted: Sat Aug 24, 2024 10:57 am
by FPGA64

I use the Digital Optical out via the TosLink to an AV receiver and on all those cores the sound is fine. My guess is you are using the 3.5 mm direct output which is frankly rubbish


Re: Scratchy sound on several cores

Posted: Sun Aug 25, 2024 7:02 am
by NightShadowPT

I am using the analog output from my MiSTress (an expansion board that fits inside an Amiga 1200 case).

To be clear, this was not a problem before, the whole system worked well.

And I need to try and test other cores/games as I couldn't find a problem with the Genesis core for instance.

Maybe the audio subsystem from my MiSTress has just died? :(


Re: Scratchy sound on several cores

Posted: Sun Aug 25, 2024 10:38 am
by NightShadowPT

Here's some additional information after some more testing:

Cores that display the crackling sound problem:

Neo Geo
Playstation
SNES
Master System
Gameboy Advance

Cores that don't seem to have the problem:

Gameboy
Spectrum
MegaDrive
PC Engine
Couple or Arcade cores (R-type and Golden Axe)

I am assuming this problem is not hardware related, but something with the cores. This happened only after my last update (btw, I have not updated my MiSTer for about 6 months).

Any ideas how I should go about this would be appreciated.

Cheers,


Re: Scratchy sound on several cores

Posted: Sun Aug 25, 2024 11:09 am
by FPGA64

Dont use the Analog output. Connect to the Toslink output and use a DAC. The analog out will never give you a good output


Re: Scratchy sound on several cores

Posted: Mon Aug 26, 2024 4:51 am
by NightShadowPT
FPGA64 wrote: Sun Aug 25, 2024 11:09 am

Dont use the Analog output. Connect to the Toslink output and use a DAC. The analog out will never give you a good output

That may be the option, but this was working well before...

I can also try and see if I can test with the HDMI out, but my screen does not have speakers.


Re: Scratchy sound on several cores

Posted: Mon Aug 26, 2024 3:46 pm
by FoxbatStargazer

I'm not hearing this in the above mentioned games on the analog out of my 6.1 Analog I/O from MisterAddons after UpdateAll. So I suspect its some interaction with your MiSTress. Though you might want to check if you have any audio filters active in the cores.


Re: Scratchy sound on several cores

Posted: Tue Aug 27, 2024 7:41 am
by NightShadowPT

I have tested these cores through HDMI (sound) and they seem to be working well.

Indeed, this is some kind of problem with the Analog Audio...


Re: Scratchy sound on several cores

Posted: Wed Sep 04, 2024 9:38 am
by pgimeno

It could be a problem with the I/O board. Someone reported another issue with audio failing for some cores and not others, and a digital board solved it.

viewtopic.php?t=8037
viewtopic.php?p=88495#p88495

I bought an optical DAC for the TOSlink output and never looked back.