Some great news, Woody and everyone. I've just recreated the Snow Leopard Server /64-bit) virtual machine from scratch with VMware Fusion 7.0.1 (having added the Sound Card virtual hardware before installing the guest OS). After installing VMware Tools and rebooting, I installed the Ensoniq 1.0.3 driver, it rebooted and, as was to be expected, no sound. Next I powered down the virtual machine machine Next I opened the vmx file with Text Edit and removed the offending line that supposedly provided hdaudio to the guest OS; I saved the file and restarted the virtual machine, and boom! Sound works.
Thank you all.
Thanks for the info guys. This was exactly what I was looking for. It was driving me up the wall. I didn't quite understand the order of steps in the process. I took detailed notes of my steps. I finally figured it out.
It didn't work until I installed the Mac OS X Server 10.6.8 Combined Update fwiw.
As an update, I was having the same problem with Snow Leopard server guest in Fusion 10.1.2 running in MacOS 10.13.4 (High Sierra) on a mid 2011 iMac 27". I first tried deleting the offensive 'sound.virtualDev = "hdaudio"' line in the Mac OS X Server Snow Leopard.vmx file, but that by itself had no effect. I then installed the EnsoniqAudioPCI_v1.0.3_Common_Installer.pkg and now I see "Line Out" as the only available option for sound output in the sound preferences pane in the guest OS, but that gets me sound to the built in speakers. I still cannot get sound to my external speakers, but at least I have some sound.