I would try a different driver or playing with the audio acceleration slider to see if it helps .

Nothing seems to change

EDIT: now the sounds sound less choppier, but it LAGS as it comes late than when it's supposed to be heard, it got a delay: for example if I shoot a rocket, I hear the sound of the rocket some seconds AFTER I shoot it instead of hearing it correctly.

Long shot :

Does disabling full duplex mode in the driver properties change anything ?

I can't find such setting in the Multimedia properties on Windows 98SE, where is it ?

The setting is in the Sound Blaster 16 device properties in Device Manager .
But I just realized the CT4750 is a SB128, so that does not apply, sorry .

Try disabling A3D . You can do it through the console with
s_disable_a3d

Reference:
http://www.helpfarm.com/files/html/commands.html

A3d won't matter if it won't initialize on inappropriate hardware.

Try changing s_mixahead and s_mixprestep, and set sound acceleration to max (setting it to minimum would lead to rather latent sound output)

A3d won't matter if it won't initialize on inappropriate hardware.

I seem to recall that a software only implementation was present .

This .inf refers to an a3d.dll which would seem to corroborate this :
http://contents.driverguide.com/content.php?i … %2FSbaPci9x.inf

as do the docs for HP's OEM version :
http://pdfstream.manualsonline.com/2/2b1d1d6a … 97e01c0037b.pdf

and this thread :
Ensoniq / Creative AudioPCI