My CT1730 fits the pattern. I can tell you however that I have seen in the past pictures of a CT1740 that had a v405 DSP and did not have a CT1730 sticker on the back. Perhaps it had fallen off, I don't know.

I compared my two SB16 with the CT1740 marking on the PCB, and they appear identical except for the DSP.

The CT1730 with 4.05 DSP is on the bottom, by the way.

I may be wrong, but I figured the SB16 CT2230 and CT2290 have overtaken the CT17xx cards since they have a generally working MPU-401 interface and an integrated true OPL3. My CT2290 has DSP 4.13 by the way, just like all my other SB16s. So what was it again with the CT17xx cards?

gerwin wrote:

I may be wrong, but I figured the SB16 CT2230 and CT2290 have overtaken the CT17xx cards since they have a generally working MPU-401 interface and an integrated true OPL3. My CT2290 has DSP 4.13 by the way, just like all my other SB16s. So what was it again with the CT17xx cards?

I believe that the CT2230 and CT2290 do not have the "illegitimate" hanging note bug but still have the "legitimate" hanging note bug (which doesn't seem to be very much of a problem at all).

See this explanation: http://www.vogonswiki.com/index.php/Hanging_note_bug

The CT1730 and any other SB16 with a DSP of 4.05 or below (and AWE64's DSP 4.16) are completely bug free.

However, everything I've read says that the CT2230/CT2290 are much less noisy than the CT1730/CT1740. I have a CT2230 and may run a comparison.

Thanks.

boxpressed wrote:

The CT1730 and any other SB16 with a DSP of 4.05 or below (and AWE64's DSP 4.16) are completely bug free.

I suppose their MPU-401 still causes slowdowns in Duke 3D (Hi quality audio settings) or Lucasarts iMuse games, at least; the AWE64 does.

gerwin wrote:

I suppose they do still cause slowdowns in Duke 3D (Hi quality audio settings) or Lucasarts iMuse games, at least; the AWE64 does.

This is true. I just tested the CT1730 + 4MB Dream DB with Duke3D, and the stuttering was still there.

boxpressed wrote:

I have a CT2230 and may run a comparison.

That would be great.
Please use this method to accurately measure SNR and frequency response with freeware VST plugins:
* Two posts one after the other.
YMF71x vs ES1688 Comparison Thread

This actually should be an agreed standard for measuring DOS audio cards, with relying on other peoples word.
Also make sure you mute everything in the SB16 mixer besides MIDI and VOICE.

boxpressed wrote:

I believe that the CT2230 and CT2290 do not have the "illegitimate" hanging note bug but still have the "legitimate" hanging note bug (which doesn't seem to be very much of a problem at all).

Type 2 "legitimate" note "bug" is a myth.
It will happen with any MPU-401 on a skipped "Note Off" command.
It probably may happen more with the SB16 in Duke3D and Tie Fighter or X-Wing CD because of the stuttering that may result in skipped "Note Off" command.

Cloudschatze wrote:

For an example of a legitimate hanging note, try an AWE32 with X-Wing CD. Though mostly inconsistent, the occasional hanging/dropped notes do occur. In this case, I believe the issue to be both related to how the game handles MIDI, and either an undersized FIFO buffer on the AWE32, or the fact that its DSP may not be fast enough to handle everything being thrown at it (MIDI + PCM).

EDIT:
Further experimentation of the hanging note bugs.
In Windows98SE I played a midi in loop with Flacosoft Midi Player, Type 2 will occasionally (rarely) occur when the 233MHz processor lagging or stuttering when moving windows or opening My Computer.
This Type 2 bug will happen with both the YMF719 at port 330 and SB16 at port 300, when the CPU stutters. It is NOT related to the SB16 at all.

Duke NUkem 3D will not even load when the midi port is in use by the midi player even though Music=NONE in dukes setup.
In fact, when selecting a sound card in the setup.exe the setup will freeze when windows is using the midi port.
Furthermore, disabling High DMA in the PNP driver (Windows or DOS) and duke3d setup will fail to configure.

Definitely a buggy sound driver of Duke3D, probably because of High-DMA which the driver forcefully uses.

I own a ct1740

on the front of the card the model says ct1740, it has the yamaha chip, it did not come with ASP, it only has the empty socket, and DSP is 4.05
now on the back of the card, the white sticker says CT1730.

SETBLASTER wrote:

I own a ct1740

on the front of the card the model says ct1740, it has the yamaha chip, it did not come with ASP, it only has the empty socket, and DSP is 4.05
now on the back of the card, the white sticker says CT1730.

I have one exactly like this as well.

I do have a very early version of the CT1740.
It has DSP 4.05, and has a non-socketed, soldered ASP chip. This was quickly removed in favor of a socket, which stayed almost always empty up to today 😉, and quickly vanished completely.
There do exist CT1740s with DSP 4.05, like mine, and 4.11, IIRC

https://imgur.com/a/VGNANNR

In case this is still of interest: I do own a Sound Blaster 16, labelled CT1740 on the front of the PCB and on the back sticker, and with a DSP version 4.05