Just guessing here

all the text to the left of J10: CDROM I/O relates to the DMA, IRQ and IO of the cdrom ports.
the text to the right of it relates to the IO address of the Windows Sound System part
While J14, J15 are for the Soundblaster part
and J16 could be the Game port Enable/Disable.

Welcome to Vogons.
The AD1848KP, as you've stated, is a 16-bit CODEC chip, but it also has built-in Windows Sound System support.

Seems like all the jumper settings are silkscreened on the PCB, which is a plus.
This is probably some Sound Blaster Pro clone, but would be interesting to know which part provides FM synthesis/emulation.

This card appears to still support the older proprietary CD-ROM interfaces from Panasonic, Mitsumi & Sony.
These are not IDE compatible.

If you are having issues under DOS, try and disable the CD-ROM interfaces and make sure you have no resource conflicts with other devices in your system.

You could try Navrátil System Information (NSSI 0.60) to try and identify the card for you. If it comes back with a DSP version < 3.0, then it's only Sound Blaster mono compatible.

jesolo wrote on 2021-07-14, 19:50:

[...]
This is probably some Sound Blaster Pro clone, but would be interesting to know which part provides FM synthesis/emulation.
[...]

that would be the MK6264 chip on the left side of the AD1848

The photos show the DMA jumpers being set inconsistently: J1 = DACK3 and J5 = DRQ1. If you use the card in this configuration, unusable sound output or system crashes are expected. Please set J1/J4 for DMA channel 3 or J2/J5 for DMA channel 1.

Riiight thats what J14, J15 and J16 are for then.

Tried changing them to no avail. If anything setting to 240h instead of 220h makes WSS play and then get distorted after a second. FM playbacks works with all settings.
Furthermore the CDROM interface is "disabled" or so says the driver but changing the settings there does change things. Mostly just breaking or distorting WSS playback but yeah.

Also under the 220 and 240h jumpers says "J16: GE". Tried setting that too whatever it is but to no avail.
And if I set the PC to 240h the PC hardlocks or gets reaaaaaaaaaally slow. Takes a couple minutes for the sound test to error out but it keeps looping without pushing enter.

I have the cards now set as follows which lets WSS and FM work without distortion:
CDROM: J1, J11, J4, J10:1-2. (DACK3, DRQ3, IRQ10, 300H.)
SB(?): 220H, GE on and off makes no difference.

I also tried setting IRQ and DMA assignments manually in the BIOS (Pentium 2 rig) but that didnt change anything. Turning the game port and MPU-401 on and off in the driver didn't change anything either.

If you are running this on a Pentium II, then that might be a possible reason why it doesn't work properly, since the PC is too fast.

I have a couple of older sound cards from that era that starts to exhibit strange behaviour once I install it in a faster system (even a fast 486 CPU with L1 write back cache).

Try in a slower system (like a 386 or slower 486).

Well I have long sold PC's of that time period, so best I could do is underclocking. Making the Pentium 2 run at 133Mhz did not have any effect. but I suppose that doesnt really help anyways?

Port 220 AdLib works fine but PCM audio still remains to only be pops and crackles.

DutchComputerKid wrote on 2021-07-15, 13:48:

Well I have long sold PC's of that time period, so best I could do is underclocking. Making the Pentium 2 run at 133Mhz did not have any effect. but I suppose that doesnt really help anyways?

Port 220 AdLib works fine but PCM audio still remains to only be pops and crackles.

Try disabling L1 & L2 cache in the BIOS and see if you can bring the speed down further.
Also see if your BIOS supports legacy assignment of DMA & IRQ's so that you can reserve for example DMA 1 & IRQ 5 for the sound card.

jesolo wrote on 2021-07-15, 14:20:

DutchComputerKid wrote on 2021-07-15, 13:48:

Well I have long sold PC's of that time period, so best I could do is underclocking. Making the Pentium 2 run at 133Mhz did not have any effect. but I suppose that doesnt really help anyways?

Port 220 AdLib works fine but PCM audio still remains to only be pops and crackles.

Try disabling L1 & L2 cache in the BIOS and see if you can bring the speed down further.
Also see if your BIOS supports legacy assignment of DMA & IRQ's so that you can reserve for example DMA 1 & IRQ 5 for the sound card.

Yeah reserving the DMA and IRQ didnt do much. Sound Blaster 16 cards, Vibra and AWE64 work just fine but this card does not.
Disabling cache makes the PC get a score of just 2 in SysBench, so thats amazingly slow. But no change.

Eh, maybe the card is faulty? I'm not sure what to check next

I also have some Aztech cards - maybe I'll try this as a future experiment and see if I can get the two cards to work together.
I normally prefer to only have one sound card (i.e., one with a DAC) in a system, since I have a number of systems to play with and I'm therefore fortunate enough to pick and choose what build I would like to play with.