By default, both Elvira and Elvira II use Soundblaster in the sound card configuration, and there's no way to change it using the setup menu because it is not configured, and in order to execute it, you must install separately DOSBOX and mount the unit where the game files are at.

I found that the settings for the sound card are saved in a .conf file inside the game's directory though, so if you want to change your card, for example, from Soundblaster to Roland which sounds much better, you just need to edit this file:

For Elvira Mistress of the Dark:

dosbox_elvira_single.conf

and change runvga gamepc /s to runvga gamepc /m1

For Elvira Jaws of Cerberus:

dosbox_elvira2_single.conf

and change runit gamepc /s to runit gamepc /m1

This way the game will use the Roland option for sound which personally I think sounds much better. Hope this is helpful for anyone that wants to change the sound card!

THX for the hint!

It is also apparently possible to restore the missing sound effects to the DOS version of Elvira II that were present in the Amiga release. [url=https://www.pcgamingwiki.com/wiki/Elvira_II:_The_Jaws_of_Cerberus#Sound_effects]https://www.pcgamingwiki.com/wiki/Elvira_II:_The_Jaws_of_Cerberus#Sound_effects[/url]

The sound effects can also be obtained at scummvm
https://www.scummvm.org/games

I think these are exactly the same, this is just for info.

Even so, Amiga music is much better than the DOS version

The aforementioned .conf file can also be modified with adding "setup" one line above the "runvga [...]" line. However, even when setup is being run before starting the game, the changes made are reflected to a bat file that is not used to start the game.

However, I'd also like to mention that changing from

" gamepc /s "

to

"gamepc /m0"

enables the "Generic Midi" output of the game. This output you can route to a MIDI expander if you have one connected.

For this you need to set a proper midi output port in the "dosbox_elvira.conf" file, section [midi], value "midiconfig". On windows, leave mpu401=intelligent and mididevice=default, bt set midiconfig=X with X being the number of the MIDI port your expander is connected to (you obviously need a MIDI interface for this, unless your MIDI expander is connected via USB).
As explained here https://dosbox-x.com/wiki/Guide%3ASetting-up-MIDI-in-DOSBox%E2%80%90X,
you can run "mixer /listmidi" in DOSBox to see a list of valid port numbers.
You can also look into DOSBOX\stdout.txt within the game folder to check which MIDI output device DOSBox is effectively using.

I currently have the following entries:
"mpu401=intelligent
mididevice=default
midiconfig=5
"

If done so, the game will output unmodified (hopefully general midi) midi to the configured output port.

I've done this and am currently listening to the game music via my V3 Sound Sonority XXL (it did cost almost 500 EUR) and the sound is really (!!!) enjoyable for a 30+ year old game.

PS: The modified BAT file is in DOSBOX\cloudsaves folder.
Valid options after "runit gamepc".

Elvira:
/p PC Speaker
/t IBM/Tandy 3 voice
/a AdLib sound card
/c CMS Gameblaster
/s Soundblaster music card
/m0 Generic Midi
/m1 Roland MT-32 / LAPC-1
/m2 CASIO CT460

Elvira II:
/p PC Speaker
/t IBM/Tandy 3 voice
/a AdLib sound card
/s Soundblaster music card
/m Roland MT-32 / LAPC-1