I tried to replicate pshipkov's workaround methods for getting DOS sound working by a) setting L1 to WT, and b) disabling L1 entirely. I tried using an AWE64Value and an OPL3 card with the 1/2*FSB divisor enabled for PCI, but still DOS sound will not work, whether or not I set L1 to WT, or disable L1. I tried the ISA bus on 7.159 MHz, on PCI/3, and PCI/4. Alternately, if I set PCI = FSB, I have no problem with DOS sound with L1:WB mode.
I find it strange that pshipkov is able to use sound in Windows (and DOS when L1:WT) when PCI = 1/2*FSB, yet I am not. Why would his system's 1/2 CPUCLK divisor be working a bit better than on my board? Could you let me know the exact markings on your PLL chip? Mine are:
As for your issues with sound in DOS, perhaps try something based on the Yamaha YMF718-S chip, preferably without the IDE connector. I don't have any issue with DOS sound using this card, provided that PCI freq = FSB via JP16. Considering your symptoms, with any luck, you may be able to get DOS sound working with this card, even if you have PCI = 1/2*66.