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Can we have a option to enable/disable the digifix on the 8580 SID #170

Open FalafellGB opened 4 months ago

FalafellGB commented 4 months ago

Its great having the digifix on the 8580 but it can create issues in sampled music or sounds created for the 8580.

A good example is the sampled music section on the first disk of the recent Performers - Next Level demo from X2023, the digifix adds a lot of distortion to the sound

Having a toggle in core menu to enable/disable the digifix for 8580 would be ideal

sorgelig commented 4 months ago

I will add an option.

sorgelig commented 4 months ago

I've added an option. Check unstable builds.

FalafellGB commented 4 months ago

Thank you

Will give it a test later

FalafellGB commented 4 months ago

finally had time to test it and it works great. Thank you (it does state OffP1FC7 in the menu though)

Edit

After more testing its surprising how much the digifix was affecting the 8580 sound. It sounds brilliant and right with the fix disabled

sorgelig commented 4 months ago

Oh, somehow slipped that semicolon. Fixed it.

FalafellGB commented 4 months ago

Thanks again. Was there ever a option to toggle the Digifix in the core ? My memory is a bit hazy ...

I have been going through more recent demos in my spare time today and it really is surprising how much difference having the fix off makes

sorgelig commented 4 months ago

Old code of SID had detection of sample playback and used different routine to playback it. New code of SID follows original hardware and requires digifix (AUX_IN to be pulled up or down). May be pull-up can be adjusted for lower level. May be you can explain more where to hear the difference.

FalafellGB commented 4 months ago

It is most noticeable in scene demos as these really push SID and musicians are using one of the available channels just to play samples a lot of time now. The 8580 is really the the scene standard for music now

The demo I mentioned originally has a couple of sections that use samples so is a easy comparison. This can be grabbed from here :

https://csdb.dk/release/?id=232976

I made a couple of videos using my phone to demonstrate the difference to a friend too :

https://1drv.ms/u/s!ArzkfFR6GJEO72yzFHiGvRc3bUsX

With the fix enabled it seems to amplify noise when using 8580, on 6581 designed music with samples it does what it should and boost the levels, so they play correctly on 8580. So is the auto setting just applying the fix on 8580 if it just detects sample playback irrelevant if it's 6581 or 8580 music ?

Hope this helps

sorgelig commented 4 months ago

Digifix is applied only for 8580. Digifix is always off for 6581. I will see if i will be able to add "auto-digifix" for 8580.

FalafellGB commented 4 months ago

Thanks The manual toggle like in the test builds does the job fine, it's nice to have manual option