Hmm... SB16 is the only card now. I went to the mixer and as I was messing around with the sliders I found out that when I was turning down the MIDI slider, the hiss goes away.

So... it's the MIDI audio that is causing the hiss??? I didn't expect that.

I'm going to turn down the MIDI slider to get rid of the hiss and see if other audio sources sound good.

Update:
Playing more with the sliders, and some of them makes more hiss that others. All tests are with speakers turned all the way up so I can hear the noise the best I can.

MIDI slider affect it the most. I have to bring it down just under a half to the point where the hiss won't go any lower.

The next is Voice slider - 3/4 way is where the hiss would not go any lower.

CD - 1 tick below max.

Treble - Affects the hiss from 0 to max. Probably won't leave it at 0 since it will affect tonal quality.

Line, MIC, PC Spkr, Bass - no effect

AGC - no effect

Output Gain - Affected (default 2x). Set to 1x to further quiet the hiss.

So I turned up my speakers so I can hear the hiss as loud as I could, then turned down the silders to the point where there the hiss is it's lowest. Here's the setting that makes my SB16 the quietest:

http://imgur.com/l6TWVSk

Unfortunately, I have to turn up the volume of the speaker to about 85% to get decent volume in games. FM music is much lower than digital audio sound fx so it seems unbalanced.

There are games that have their own built-in mixer that turn the volume way up such as Duke 3D. Doom has a volume control, but it looks like "max" is just max of whatever the sound mixer allows, but Duke 3D seem to override the mixer settings, so things can get loud.

Wolf 3D doesn't have volume controls, but it sounds like it takes over the sound card's mixer and jacks up the volume all the way up! Because when I launch it, you can hear the hiss. Then you get an explosion of sound (since the speaker is up at 100% volume since every other game volume is low).

MIDI is responsible both for FM (OPL) and Wavetable Return volumes.
It can be that the wavetable amplifier on the SB16 is noisy or the wave table itself if you use one (unplug it to test). It also can be that the FM DAC is noisy.

The MIDI volume dial on my CT2230 has no effect on the hiss level, maybe because I have nothing connected to the wavetable header.
If the wavetable amplifier amplifies noise, you can build a small cable that will ground the L/R signal inputs where the wavetable card would send signal (need to find which pins),
thus making sure there is absolutely nothing at the amplifier input.

Do not adjust the mixer by listening to hiss levels, this may ruin the balance between Voice and MIDI which should be equal in the mixer.
CD, Line Mic, and their output X should be disabled unless you actually use them, all output X's should be unticked unless you use them.
Keep Bass and Treble at middle, for flat un-altered sound.
Output gains to x1, not 4x.

Keep Voice and MIDI at max and Master at one click below max with output gains of x1, this should give the optimum balance for games, and standard consumer level line-out signal voltage (−10 dBV) for speakers.

James-F wrote:

MIDI is responsible both for FM (OPL) and Wavetable Return volumes. It can be that the wavetable amplifier on the SB16 is noisy […]
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MIDI is responsible both for FM (OPL) and Wavetable Return volumes.
It can be that the wavetable amplifier on the SB16 is noisy or the wave table itself if you use one (unplug it to test). It also can be that the FM DAC is noisy.

The MIDI volume dial on my CT2230 has no effect on the hiss level, maybe because I have nothing connected to the wavetable header.
If the wavetable amplifier amplifies noise, you can build a small cable that will ground the L/R signal inputs where the wavetable card would send signal (need to find which pins),
thus making sure there is absolutely nothing at the amplifier input.

I have nothing connected to the wavetable header.

Do not adjust the mixer by listening to hiss levels, this may ruin the balance between Voice and MIDI which should be equal in t […]
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Do not adjust the mixer by listening to hiss levels, this may ruin the balance between Voice and MIDI which should be equal in the mixer.
CD, Line Mic, and their output X should be disabled unless you actually use them, all output X's should be unticked unless you use them.
Keep Bass and Treble at middle, for flat un-altered sound.
Output gains to x1, not 4x.

Understood. This was just an experiment. This is on a scratch HDD (actually an SD card over IDE adapter

I can try other suggested settings if you have any. Thanks for advising.

Update:
I turned up the MIDI one more tick to be closer to the Voice slider. If I put one more tick above even THAT I would get a lot of hiss. Some how going over that threshold the hiss gets so much worse.

Unticking the check boxes in input doesn't help. Unticking the boxes in output doesn't help either since the hiss is already controlled by adjusting the sliders. I already have everything unchecked except for CD (needed for CD audio in some games).

I adjusted the output gain back to x2. That brought the hiss back up, but it's a compromise between hiss and total volume. This made the overall volume level a bit tolerable in games.

Update 2:
Swapped back to the AWE64, and absolutely no hiss even at max speaker volume. All in-game music/sound is in decent volume when speaker is 40%.

I got more hiss than I was expecting too from my CT2230 during testing tonight. I have a wavetable DB on it. No better than the CT2760 or even the CT1730. Could be just my setup.

WARNING the following may kill your card or PC if not done right.
I repeat, if you jumper the wrong pins and pull 12V to ground you may fry your sound card or PC power supply.
* I personally tested it with no harm.
Disclaimer: I rid myself of all responsibility of anything going wrong, ever.

Now, all you have to do to silence the wavetable amplifier is to jumper the pins as in the images.
This will pull the audio signal form the wavetable to ground, so if there was a chance that some hiss was amplified, now it's gone.
With the wavetable header jumpered I get absolutely no change in hiss when moving the MIDI slider.
The biggest contributor to hiss on my CT2230 is the Voice slider (counting out CD, Line and Mic), but that's expected.

Some questions for you guys,
When the sliders are all set to zero except Master and Gain, does the card hiss?
What slider produces the most hiss, besides Master and Gains?

James-F wrote:

Some questions for you guys,
When the sliders are all set to zero except Master and Gain, does the card hiss?
What slider produces the most hiss, besides Master and Gains?

Thanks for that info. I'll be careful with that info and see if that can help. That shouldn't affect the MPU401 interface, though, right? Just the wavetable analog input amplifier (since a wavetable would have to output an analog audio signal for the sound card to mix in with the other audio sources).

To answer your questions:

When the sliders are all set to zero except Master and Gain, does the card hiss?

There is still a bit of hiss, but it's so low that I would consider it "quiet" (slightly louder than the AWE64).

What slider produces the most hiss, besides Master and Gains?

For me it's the MIDI slider. The second would be the Voice (as you can see the slider position). The voice slider also produces a bit of a tone as well after going past that position. Then next after that is the CD slider. Just one tick below max and that solves it. The treble slider also affect hiss linearly. Even one tick above 0 you can hear the hiss go a bit louder, and every tick just make the his ever so slightly louder. Unfortunately since it also adjusts the overall tonal quality of sound, I leave it at mid.

How far the slider is from max seem to reflect my experience with the exception of MIC and PC Spkr. With the latter 2, even at max it's quiet. I turned them down anyways since I don't want to hear their input. Again, for your reference: http://imgur.com/l6TWVSk

That shouldn't affect the MPU401 interface, though, right?

No, it just shorts the analog inputs to ground.

For me it's the MIDI slider.

I don't think it is the FM chip that makes the extra noise because the integrated CT1747 is identical in all CT2230 models.
Please try the jumper solution and make sure you triple check before powering on the PC.

EDIT:
The analog wavetable inputs go through a 22k resistor straight into the operational amplifier MC3403 which is always amplifying.
I have traced that with my multi-meter.
Furthermore, it seems this MC3403 also amplifies the CT1978 (OPL clone) on my CT2950, since the MC3403 has four OP-amps, so the MIDI volume dial is combined for the FM and Wavetable.
Grounding the wavetable analog ins has no effect on FM sound whatsoever.

After jumping those two pins, I am still getting the same level of hiss. Just to make sure, I took the jumpers off with the slider maxed so I can detect any changes. None unfortunately.

Here's a quick video I made playing around with the mixer settings.

https://youtu.be/GdcVedXM88s

In anticipation of receiving a Turtle Beach Maui on order, I decided to pair a Turtle Beach Pinnacle with my AWE32.

The Pinnacle has digital audio (not SB compatible) and a 4MB Kurzweil wavetable ROM. It has two line in inputs, one that is supposedly quieter than the other because it is not used for recording (?). I sent the AWE32's line out into this line in on the Pinnacle and fired up Duke3D.

I have to say that the results are so good that I may not go back to 4MB Dream wavetable DB I had stuck on the AWE32. Like everyone else, I had to use 11KHz or 22KHz (at best) samples or else the game would stutter. Now I'm using 44KHz, and the game is as smooth as butter.

I know that anyone using a wavetable DB on a non-Creative card doesn't get stutter, but my setup allows for 16-bit sound, not SB Pro-compatible 8-bit sound.

I think that if Duke3D, 16-bit sound, and GM music are important to you, a wavetable ISA card plus a SB16 are the way to go rather than using the SB16's MPU-401 with a DB or external module.

Right now I have a AWE64 paired with a SB16. The SB16 is only used for the MPU-401. This unfortunately means no real OPL3, but I have a choice between non-OPL3 FM synth, AWE wavetable, and SC-55 music.

I just don't want to use any of the SB16 analog outputs since they prove to be noisy. Kind of sad to use a SB16 this way, but it's the only non-PnP audio card I have. I had a lot of issues trying to pair up the Yamaha card with the AWE64 (which is also PnP).

I forgot to mention this is my SS7 machine.

My Slot 1 machine has a single Yamaha YMF719 ISA card (PnP) with the Dreamblaster X1. Only issue I have with this setup is Duke Nukem 2 (some explosion sounds not playing correctly). Other than that, it's a dream!

I agree about the Yamaha YMF71x cards, they are indeed almost perfect for dos gaming.
Make sure to set SB to 1 in the mixer as per THIS thread.

The SB16 on the other hand is ridden with bugs, not a single one of them is bug free.
From personal experience, I can't recommend it for anything.

James-F wrote:

I agree about the Yamaha YMF71x cards, they are indeed almost perfect for dos gaming. Make sure to set SB to 1 in the mixer as p […]
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I agree about the Yamaha YMF71x cards, they are indeed almost perfect for dos gaming.
Make sure to set SB to 1 in the mixer as per THIS thread.

The SB16 on the other hand is ridden with bugs, not a single one of them is bug free.
From personal experience, I can't recommend it for anything.

Thanks for that tid-bit! More bugs and weird behaviors found, and workarounds. 😀

Speaking of which, I remember you creating a potential Duke Nukem 2 audio fix by transcoding the 8-bit to 2/3/4-bit ADPC files to PCM and repacking it. I didn't get a chance to try it yet because I was focused on my SS7 setup (non YMF719). I have to plug my Slot 1 PC back up to a head/key/mouse/spkr and check it out.

Did anyone already try it and get back to you on the results?

Edit: Actually Cyberdyne created the potential fix. Searching the thread and found it here:
Duke Nukem 2 ADPCM fix?

James-F wrote:

I agree about the Yamaha YMF71x cards, they are indeed almost perfect for dos gaming.

I thought the ES1688 AudioDrive came out on top in your comparison thread?

The ESS is also a great SBPro card.
Now that the YMF71x mixer abnormality is figured, it is even better than it was at the time of the comparison.
They both have their disadvantages, and both a a great choice for DOS gaming.

I will edit the ESS vs YMF comparison thread with the YMF mixer fix.

BTW, does your SB16 CT2230 have that massive hiss volume after past 3/4 like in the video?
https://youtu.be/GdcVedXM88s

No, my MIDI slider on the CT2230 is silent all across its range.
It also appears/sounds that the volume slider is logarithmic therefor the most volume/hiss change would be in the few last steps.

I think the CT1703 DAC chip is responsible for all the digital-to-analog conversions of the SB16 card, Voice and MIDI.
So for some reason the CT1703-T is noisier than the CT1703-TBS/A and that is most apparent on the MIDI slider.

Thanks for all the great information on this forum, including this thread, and others.

I'm slowly making a pre-1995 DOS 6.22/WFW 3.11 era computer and looking at picking up either the CT2230 or CT2290. I was leaning toward the CT2230, but with the various potential issues mentioned in this thread, it seems like it would be rather difficult to source a preferred revision. I do prefer the fully loaded and feature rich look of the CT2230, but with that aside, would it just be better to go with the CT2290, or are there similar issues with that model as well?

Thanks.

WR3ND wrote:

Thanks for all the great information on this forum, including this thread, and others.

I'm slowly making a pre-1995 DOS 6.22/WFW 3.11 era computer and looking at picking up either the CT2230 or CT2290. I was leaning toward the CT2230, but with the various potential issues mentioned in this thread, it seems like it would be rather difficult to source a preferred revision. I do prefer the fully loaded and feature rich look of the CT2230, but with that aside, would it just be better to go with the CT2290, or are there similar issues with that model as well?

Thanks.

They're exactly the same in my experience, excluding some minor differences in CD-in headers, etc. One of them is missing the socket for the effects processor chip thing that isn't used for anything.

badmojo wrote:

They're exactly the same in my experience, excluding some minor differences in CD-in headers, etc. One of them is missing the socket for the effects processor chip thing that isn't used for anything.

Thanks. I was also wondering if the CT2290s suffered from occasionally lower performing components as well.

In the meantime I managed to find this decent looking CT2230, so I went ahead and snagged it while I could. ↓

https://i.imgur.com/nIV3dds.jpg

Hope I got a good one.

James-F wrote:

GuyTechie wrote:

--snip-- 029417 […]
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--snip--
029417

12.jpg

--snip--

I thought I would register on this forum to provide my input. I just purchased the CT2230 029417 revision from eBay (for a 486 DOS gaming maching), and the pictures on the page show that it is missing the Mitsumi and Sony drive header (but the solder pads are there)

The card I bought.
https://www.ebay.com/itm/272890082827