That is an YMF724 chipset, why would it be noisy?, it uses a Sigmatel DAC.

For some reason this card would pick up a lot of bus noise. Whenever the hard drive was loading for example, I could hear it through the speakers (similar to a GSM cellphone close to a speaker). Also, it made a lot of popping noises, and I could hear a hum when connected to my AV receiver. That was with the internal amp disabled. At the time I was comparing this to my AWE64G, which had very clean output.

The OPL3-SAx cards look interesting. If one happens to pass my way I'll give it a shot (probably won't bother wasting $20 on ebay).

Oh, and I did examine my SB16 CT1770. When jumpered to the "amp disable" position, the speaker out port leads directly to the CT1745A chip...actually there is a small surface mount capacitor of unknown value between them. I think that small capacitor may be the key to bypassing the amp on an SB Pro.

Anonymous Coward wrote:

For some reason this card would pick up a lot of bus noise. Whenever the hard drive was loading for example, I could hear it through the speakers (similar to a GSM cellphone close to a speaker). Also, it made a lot of popping noises, and I could hear a hum when connected to my AV receiver. That was with the internal amp disabled. At the time I was comparing this to my AWE64G, which had very clean output.

That is not nice indeed. I have two cards based on the YMF724, from A-Trend and A-Open IIRC, the former gives pops when I turn on the computer, but other than that I have no issues with them.

Anonymous Coward wrote:

The OPL3-SAx cards look interesting. If one happens to pass my way I'll give it a shot (probably won't bother wasting $20 on ebay).

OK, it should not be challenging to get one on ebay though, there are plenty for sale.

h-a-l-9000, do you have any photos of the shield you added to the card? Where did you get your materials, and how did you cut them?

Oh this was not a permanent modification as I don't regularly use it. The isolation (the closer the shield is to the pcb the better) was what you usually find in a PC power supply, the shield from a monitor in which it had served a similar purpose. It's probably tin.

With the earphones on I moved the shield across the back of the card to find the spot where noise would be minimized. The shield was connected to ground by alligator clips.