MiSTer FPGA Forum

Hi I seem to be suffering from a really low volume on the genesis core to say the SNES or NES cores. I have to turn up my amp twice as much - is this normal?
Thanks

Yes it is normal, the way the audio is currently implemented they have to keep the gain/volume low in that core to prevent clipping/distortion.

I would assume much rework of the audio implementation would need to be done to be able to increase volume without running into distortion problems.

For now you can just lower the volume on the other cores to match Genesis audio levels, if the drop in volume bothers you when switching to Genesis core.

And if you do not know.
You adjust the volume on core by core basis by opening the mister menu then press left and you can adjust core volume there.
Can't remember if you also have to save settings for the volume level to "stick".
Save settings is done by opening mister menu press right and close to the bottom is save settings.

Ok that's good to know that it isn't specific to my setup.

I'll do that for the other cores as you say however the big problem comes when moving between cores and the loud audio pops and cracks that happen when using the IO board's 3.5mm jack with mini TOSLINK (that I've also just opened a support request in general discussions for).

If you have the volume up where you need it for the Genesis core I fear it'll damage my speakers - my audio interfaces input's lights go bright red even at 50% volume let alone the 75% that the Genesis core seems to require (I have most other cores at 25%)

You can solve that problem using a preamplifier. A decent DAC will give more volume too , but the preamp allow you to adjust it using a physical knob.

@pacoarvade I'm not sure a pre-amplifier helps in this scenario.

Its not a problem that I cant turn it up loud enough - I can using my Scarlet 2i2 audio interface (which if I'm not mistaken is acting in part as a pre-amplifier) but when I do turn it up I then run the risk of forgetting its up loud and then damaging my speakers when I change cores due to the popinng which in turn is due to using the analogue io boards 3.5mm jack mini-toslink.

I'm pretty sure this must be a common setup i.e using the analogue io boards 3.5mm jack?

I could understand it helpig if there was some kind of filter to protect against large input spikes but the Scarlett doesnt have anything like that - I'm not sure any pre-amplifier does?

On the topic of audio, does anyone get a loud "THUD" every time they reboot or launch a new core? It even happens with optical TOSLINK.

I heard a ground loop isolator can get rid of it but I haven't tried it.

Luckily, my HDMI switch has an optical audio extrator built in, so I can get clean audio that way. It sounds significantly better.

I try to avoid the 3.5mm audio out on the IO board whenever possible.

@chanunnaki thats the sound I'm talking about when I say 'pop' - I think 'thud' is a better description of it though. I've posted in General Discussions about it as it sounds really bad for the speakers - the low volume issue on the Genesis core amplifies the thud problem.

chanunnaki wrote: ↑Tue Mar 30, 2021 4:33 pm I heard a ground loop isolator can get rid of it but I haven't tried it.

Optical IS a ground loop isolator (in fact better then most normal ground loop isolators), as in there is no electrical connection between two units, and because optical/TOSLINK is using light and uses plastic/glas as it's medium it does not lead any electricity.


I do not have any pop/thump or any sound at all using the 3,5" toslink out to my headphone amp.
I do have the digital IO board tough and do not know if that is why.

Interesting that you don't have it with the digital IO - I have one of those sitting idly by - I'll try it.

I've found this:

https://electronics.stackexchange.com/q ... ack/323360

Sounds like my problem might be a 'DC pop' when swapping cores.

Noticed when I boot up the bbc micro core or Archimedes core tonight the reassuring ‘beep’ you hear has gone since the last few days ?

Shuffle7 wrote: ↑Sat Apr 03, 2021 11:05 pm ‘beep’ has gone?

Months since i even started any of those cores so can be wrong.
But could it be a core setting that turns on/off the beep?

And just had a thought! (but calm down no fire only heavy smoke )
What psu/transformer are you using Billy?
If it is the 2A one that comes with the DE-10 it can have problem if you start to add too many things.
Probably a long shot but it´s possible that when starting a new core and the FPGA itself is being rewritten/configured that maybe it draw a little bit more power and you are on the limit already.
And therefore gets an audio pop.

I´m using the meanwell 4Amp psu.