The MPU401 only passes over MIDI information about what it wants your MIDI synth to play. So the MIDI module is only outputting music. Your Nova should still be outputting sound effects out via it's speaker out.

Some MIDI modules have an audio in jack so they will mix the sound card's output with the MIDI music it's generating. Or you could run a cable from the MIDI synth's output to the line in of the sound card and mix the audio there.

With current devices on the market, I instead recommend getting a cheap audio mixer. That will let you externally set the volume levels of each input channel independently. And the even a four channel, $25 mixer will introduce much less noise than what you get mixing in your old hardware.

SScorpio wrote on 2025-11-26, 15:42:

The MPU401 only passes over MIDI information about what it wants your MIDI synth to play. So the MIDI module is only outputting music. Your Nova should still be outputting sound effects out via it's speaker out.

Some MIDI modules have an audio in jack so they will mix the sound card's output with the MIDI music it's generating. Or you could run a cable from the MIDI synth's output to the line in of the sound card and mix the audio there.

With current devices on the market, I instead recommend getting a cheap audio mixer. That will let you externally set the volume levels of each input channel independently. And the even a four channel, $25 mixer will introduce much less noise than what you get mixing in your old hardware.

Thank you for this! I took the Bulky Midi output and fed it to Line In on the Nova, then plugged the speakers into the Nova as normal so now all good. Appreciate you.

It does seem that Duke Nukem 3D will only run with General Midi and no sfx, or sfx and no General Midi, or both set to Sound Blaster. But I guess that's a question for a different day for now.

CravenCoyote wrote on 2025-11-26, 18:39:

Thank you for this! I took the Bulky Midi output and fed it to Line In on the Nova, then plugged the speakers into the Nova as normal so now all good. Appreciate you.

It does seem that Duke Nukem 3D will only run with General Midi and no sfx, or sfx and no General Midi, or both set to Sound Blaster. But I guess that's a question for a different day for now.

"will only run with" means it crashes?

NeoG_ wrote on 2025-11-27, 00:16:

"will only run with" means it crashes?

With General Midi for music and Sound Blaster for sfx, the game does start but runs incredibly slowly, like a slide show. The audio is garbled and there is no music at all. Yet interestingly, the music and sounds all work in the Setup tool.

CravenCoyote wrote on 2025-11-27, 00:33:

NeoG_ wrote on 2025-11-27, 00:16:

"will only run with" means it crashes?

With General Midi for music and Sound Blaster for sfx, the game does start but runs incredibly slowly, like a slide show. The audio is garbled and there is no music at all. Yet interestingly, the music and sounds all work in the Setup tool.

Kinda sounds like a hardware issue with the controller chip if this behaviour happens in pure DOS mode.. What happens if you downgrade the SFX to sound blaster 2.0, mono 11Khz mixing alongside General MIDI?

NeoG_ wrote on 2025-11-27, 00:51:

Kinda sounds like a hardware issue with the controller chip if this behaviour happens in pure DOS mode.. What happens if you downgrade the SFX to sound blaster 2.0, mono 11Khz mixing alongside General MIDI?

The same thing happens if I use those settings. Works fine for Doom though, seems to only be Duke3D

CravenCoyote wrote on 2025-11-27, 01:06:

The same thing happens if I use those settings. Works fine for Doom though, seems to only be Duke3D

I forgot to mention, are you also selecting 8bit mixing?

NeoG_ wrote on 2025-11-27, 01:34:

I forgot to mention, are you also selecting 8bit mixing?

In the Duke3D audio setup, there is no difference whether I choose 8bit or 16bit