First post, by James-F
Known Bugs and Deficiencies:
* MPU-401 Hanging Note Bug.
All Sound Blaster 16 and AWE32 that don't have a CT1747 chip have this bug.
DSP versions 4.04, 4.05 and 4.16 (AWE64) will not suffer from this bug.
The hanging note occurs randomly and sounds like a high pitched note that is not part of the midi music signal.
* MPU-401 Stuttering with high sampling rates.
In Duke Nukem 3D or Tie Fighter the game will stutter when using the MPU-401 midi interface.
It occurs with all SB16 to AWE64 sound cards, including Vibras, and those with the CT1747 chip.
Happens only when using high sampling rate digital audio (above 11kHz) along with the MPU-401 General Midi music.
* Single-Cycle DMA Clicking (Non Vibra).
A click will be heard after a sample is done playing with games that use Single-Cycle DMA mode for audio.
All DSP 4.0x to 4.13 are affected including the AWE32.
DSP 4.16 of the AWE64 is not affected, and is free of this bug.
The Vibra cards are not affected by this bug, but have the ringing bug instead.
Great Hierophant from Nerdly Pleasures has some examples of these "clicks and pops" as he calls them too:
nerdlypleasures.blogspot.co.il/2015/05/ ... yback.html
In this "SB16 programming" link the author states "This causes a click between each block," when talking about single-cycle DMA.
* Ringing/Hissing artifacts, Vibra only.
A faint high pitched ringing will be heard after a sample is done playing.
Sometimes the card will hiss instead of ring, but the cause it the same.
In any case, these "artifacts" can be heard only on the Vibra cards.
* Vibra CT2504 series Audio Distortion.
High volume sounds, mainly in DOS games, will distort the CT2800 and CT2890 Vibra cards.
* CQM vs OPL3.
If the card has a CT1978 chip on board, it has the Creative clone of the Yamaha OPL3 chip which sounds different.
Technically not a bug but a deficiency if one is looking an authentic OPL3 FM sound.
All AWE64 have the Creative clone chip built in.
* Self Noise
Self noise primarily comes from the DAC chip of the SB16.
CT1701 is the oldest and noisiest mainly on the SB16 CT1740 cards.
CT1703-T is slightly better but still considered noisy.
CT1703-TBS and CT1703-A are noise free an appear on the later SB16 cards including the AWE32 and AWE64.
It seems that most of the noise comes from the MIDI slider in the Mixer with cards using the CT1703-T DAC chip.
The MIDI slider is responsible for the Wavetable header and OPL volumes combined.
I attached an audio sample package with all the known bugs, so you can hear the them yourself.
As a side note, the SB16 has dynamic brickwall lowpass filtering which changes depending on the sampling rate frequency,
unlike the SB2.0 and SBPro which have a simple static lowpass filter and is the same for all sampling rates.
I welcome more findings, knowledge and sound samples for archival purposes on this thread.
Many thanks to Great Hierophant of Nerdly Pleasures Blog which was the main source of a lot of information in this post.