Understanding Soundblaster cards is a fun game, but don't do it to death. You could study that one card for a lifetime and then you'd understand one SB16 of a certain ctXXXX number or, more likely, the third of cards of that number that were actually built exactly that way and not missing some part or featuring some other one.
My point being: They are a mess.
There are several lists like this one and none is perfectly comprehensive, complete or English:
http://www.amoretro.de/guides-workshops/creat … r-modellnummern
My two cents on some parts:
The CT1748A is the so called ASP / CSP chip. It may be used for decoding and encoding simple audio algorithms like ADPCM.
- utterly useless as exactly one game ever supported it. Mainly a joke and collector's item. But in the latter sense, nice if present.
The Yamaha YMF262 is the OPL3 chip. It is a music synthesizer.
- Synonymous with game sound in the 90s but realized in so many variants. That one here is the original one, though.
The CT1745A is the mixer chip.
- That one is important in function, but rarely makes a difference in use, afaik.
The CT1701 is a DAC that is a bit noisy.
- And some are less noisy or noisy AF but most cards are not exactly hifi.
The CT1741 is the DSP.
- The version number decides whether it has a certain bug screwing up MIDI playback.
The CT1746B is the bus interface chip.
- Think that's what makes it a first generation SB16, but don't quote me on that.
General thoughts on that card:
The 2700 seems rare. It looks much like the 1st gen ct17xx cards, but with a Mitsumi CD-ROM interface. For whatever reason they'd call that one 27xx... don't try too hard to make sense of that, I like to think they used dice. But, SB pro 2.0 with Panasonic Interface is ct1600 while the one with Mitsumi port is ct2600 - so that would be logical, for a change.
By basic features, the one pictured here has
- Pre-PNP interface
- ASP / CSP chip present
- real OPL3
- volume wheel on the bracket - only the first ones had that
- single CD-ROM controller for proprietary CD-ROM drives from Mitsumi - since those are almost nonexistant, that's virtually useless. (later ones had IDE)
- a "wave blaster" header for MIDI daughterboards. All full SB16 and AWE32 had those, but not the "value" or budget cards or the AWE64
(While AWE32 and AWE64 are mostly SB16 with extra steps.)
- that silly white "Mitsumi style" CD-audio-in header. Basic cables have only the black 2.54 mm dupont plugs which are much more common, but the white ones can be found.
The ST TEA2025B in the upper right is a very simple stereo amplifier IC providing output levels sufficient for headphones or small passive speakers. AFAIK, the similar chip from Philips is better, and many contemporary sound cards used that one, but not CL. It should be avoided anyway by disabling it via some jumpers or using the alternative "line out" on some cards.
So, think you've hit a bit of a unicorn there, congratulations. Take good care of it.
Chances are, that DSP chip is version 4.05, 4.11 or 4.12 which would mean you could mess around with external MIDI modules or addon cards without the dreaded bug.
And also, it's pretty noisy, but none are perfect.