Terrific!

great info

Solution: use a separate card for MPU-401 and do some soldering surgery to an older sbpro/sbpro2/sb16/awe32 with a genuine opl2/3, upgrading the DSP to 4.16 and better DACs.

^ allright, I want to "fix" my CT2230's DSP and DACs , do you have the info necessary for that?

As far I understand the "DSP" is just an intel microcontroller with hard coded "DSP" software, so my immediate idea would be to simply try swapping in a 4.16 chip from a donor card. Of course, would hope it's the same micro controller, else the swapping becomes complicated getting the voltage and pinout hooked up correctly. Same deal with DACs.

Technically the CT1703-A can be replaced, but the DSP is not a stand alone chip like on the SB16/32 but it is built into the main AWE64 chip.

Well, my hearing is bad enough, tinnitus, that I didn't hear the clicking in the examples.

Turn it up.

I listen through flat frequency response studio monitors or in-ear monitors so I can hear everything.
The click is definitely there and clearly audible.

It's supposed to be at the end right? It's very slight to me, and when you take the low quality recorded sound effects into account, it doesn't seem the biggest issue to me, but obviously it's annoying for those that pick it out.

Great to have some good examples!

A CQM vs. OPL difference is apparent in Doom E1M1 - the CQM's emphasis really grates after just a little while. The instrumentation is pretty simple, though (not as such, but one of the main pieces they likely tuned it for). There are probably some more glaring cases to compare out there, but I don't have a CQM card to make my own comparisons.

awgamer wrote:

It's supposed to be at the end right? It's very slight to me, and when you take the low quality recorded sound effects into account, it doesn't seem the biggest issue to me, but obviously it's annoying for those that pick it out.

No, the clicking is there throughout the Apogee fanfare in the Alien Rampage (edit: Alien Carnage 😀) example. Like small pops or clipping artifacts or something.

James-F wrote:

All AWE32 except the very first model (CT2760) have the clone

Not true, i have a non pnp ct3900 awe32 with the ct1747 chip which contains a real yamaha opl.

dondiego wrote:

James-F wrote:

All AWE32 except the very first model (CT2760) have the clone

Not true, i have a non pnp ct3900 awe32 with the ct1747 chip which contains a real yamaha opl.

You're right, fixed.

firage wrote:

No, the clicking is there throughout the Apogee fanfare in the Alien Rampage example. Like small pops or clipping artifacts or something.

Right.
Here is some more info on how it works:

Some games like Alien Carnage will use continuous audio stream in single-cycle DMA mode, you will hear a click each time a sub-block of sound ends and an interrupt is sent.
Same thing can be heard in the Wolfenstein 3D Door example where the door opening sound actually constructed of several sub-blocks hence the many clicking sounds DURING the audio stream.
At least this is how I understand how it works.

The wolf3d door sound is a soundcard test I do when I get a non-sb card... most of the times it just cuts off, ie you only hear the first part of the sample. I also found this is true to several old SB clones (chinese clones - not compatible name chipsets like opti/crystal etc)

keropi wrote:

The wolf3d door sound is a soundcard test I do when I get a non-sb card...

If you read the Single-Cycle DMA mode description I've posted it reads:

At the end of a sub-block transfer, the DSP will generate an interrupt to the application.
On receiving the interrupt, the application reprograms the DMA controller...

If the DSP (or DMA?) is plagued with this bug, there will be a click at the end of the sub-block or a complete silence after the first sub-block interrupt in clone cards as you say.
So yes, it appears that Single-Cycle DMA mode is one buggy mode even in official Creative cards.

firage wrote:

Great to have some good examples! […]
Show full quote

Great to have some good examples!

A CQM vs. OPL difference is apparent in Doom E1M1 - the CQM's emphasis really grates after just a little while. The instrumentation is pretty simple, though. There are probably some more glaring cases to compare out there, but I don't have a CQM card to make my own comparisons.

awgamer wrote:

It's supposed to be at the end right? It's very slight to me, and when you take the low quality recorded sound effects into account, it doesn't seem the biggest issue to me, but obviously it's annoying for those that pick it out.

No, the clicking is there throughout the Apogee fanfare in the Alien Rampage example. Like small pops or clipping artifacts or something.

I guess it would help to hear the same recording without the pops.

I made one of this game in the earlier thread, with the CT2940: download/file.php?id=27528

What about the ct2290? I know there are two variants. One with the left creative ic missing and one with. I have ine with.

Great work summarizing it all, and a nice selection of samples. 😎

Here are my subjective impressions:

• The Vibra distortion in Skyroads sounds quite bad, but the ringing is somewhat bearable. Which distortion type is more common?
• The single-cycle DMA clicking is clearly audible, but it seems that the relative volume differs. In the Duke2 sample it's pretty annoying, for instance, but in the PoP footsteps it's quite benign. I imagine it would be less noticeable, and thus less disturbing when if is MIDI playing in the background.
• The MPU-401 hanging note is atrocious and is easily the worst artifact of everything demonstrated here. I can understand why people would find the affected cards totally unsuitable for passing MIDI to an external device. How frequent would it be in practice? I.e., what percentage of MIDI tracks is affected?
• The CQM vs OPL3 is a good choice of track, and the description of CQM as more metallic and buzzy is pretty accurately demonstrated in this tune, and it is potentially grating. Based on other comparisons I've heard, this is actually probably one of the more obvious ones. In many other tracks, the difference will not be as pronounced.
• For instance, there is a nice comparison of OPL3 vs CQM here, with 4 different tracks and several cards (3 OPL, 2-3 CQM). The differences are there, and I clearly prefer the OPL variants, but for some tracks the differences are fairly mild, to the point that I'm not sure I would have noticed them if I weren't looking for the tell-tale signs, and not even sure I would have correctly identified it in a blind test.

dr_st wrote:

The Vibra distortion in Skyroads sounds quite bad, but the ringing is somewhat bearable. Which distortion type is more common?

The Ringing is more common, and indeed bearable.
Sometimes it is louder than I would want, even with music in the background.
Same with the clicking, sometimes it is just annoying and I can't not hear it even with background music.

. How frequent would it be in practice? I.e., what percentage of MIDI tracks is affected?

More often than anyone would want, a single note is enough to destroy the whole composition (IMO).

As for CQM, I don't like it one bit.
ESFM is a great OPL clone and indistinguishable without a direct comparison, can't say the same for CQM.