Hi!
There are multiple devices designed to be LPT sound cards. To give a quick summary, I did a little research regarding this topic and these are the main sound options:
Covox Speech Thing (Intersound MDO/8 bit DAC/CVX4/FTL Sound Adapter/SoundJR… they are all mostly compatible), Stereo-on-1, Disney Sound Source, OPL2LPT/OPL3LPT, TNDLPT, CMSLPT, S2P and Digispeech Plus DS311.
To give you a quick rundown:
Covox Speech Thing is a simple device that is supported natively (without a driver) in about a hundred games. Furthermore there are some custom drivers able to simulate Tandy sound standard, but for this you need 386 or better CPU. Sound can be quite impressive but you need a bit more powerful machine since computer has to send sound samples with the right timing. There are multiple videos showcasing the Covox Speech Thing on YouTube (LGR, The 8 Bit Guy, Retro Erik etc.) You can buy the CVX4 from Serdashop for this sound option.
Stereo-on-1 is basically the same device, but with support for stereo sound. Most of the times you have to build one yourself since there was no mass production of it. There are only a couple of games (about 20) that support it natively and the computer has to be even more powerful than with the Covox. It is a cool device but I would not recommend it for games.
Disney Sound Source was a device produced and sold by Disney. Technically it is close to Covox, but with added buffer, therefore you don't need that powerful machine. The sad reality is that although quite a few games support it natively (about 150 games), it is mostly used only for sound effects due to its poor sound quality. Again, there should be some videos on YouTube (I remember The 8 Bit Guy did video on this, but there are surely even more).
Digispeech Plus DS311 was a bit obscure device. It is Sound Blaster compatible, but only with a driver, so at least 386 is needed. Also, the device is hard to acquire and there is at this moment no modern recreation. LGR made a video on this.
OPL2LPT/OPL3LPT is a modern device sold by Serdashop. It has limited native support (just a few modern games such as Planet X3), but you can add support for most AdLib-compatible games with ADLiPT driver (again needing 386 or better). But also, there is a patchibg utility called AdPatch, which can patch drivers of some games (the list can be found on the GitHub page of the ADLiPT) and use AdLib compatibility even on older machines. But the patching utility supports about 100 games. The 8 Bit Guy made a video about it, so did LGR.
CMSLPT and TNDLPT are also modern devices sold by Serdashop. CMSLPT has driver support for Creative Music System (or Gameblaster) and TNDLPT has driver support for Tandy Sound System. Natively are these devices supported in a few modern games, but with drivers (requiring 386+) you can achieve sound support in about 100/200 games. As far as I know there are some instructions for CMSLPT patching of games, making it possible to use them even on older machines, but I have never tried it. Also, not sure whether TNDLPT has any such instructions available. These devices are compared in a video by Retro Erik.
S2P is again modern device sold by Serdashop with General MIDI compatibility. Native support is close to none, but you can use a modified version of SoftMPU for MIDI support. With it, you can get great sound in a lot of games, but again, you will need 386 or better.
picovox is a small device designed by me (hehe, product placement). It can be switched between Covox/Stereo-on-1/Disney Sound Source/OPL3LPT/CMSLPT and TNDLPT with a simple control utility available for DOS (supporting even old machines). The advantage is that you can get support for all the listed devices in a small, inexpensive device (beware, it emulates CMSLPT, not Gameblaster, you still need the correct driver program). Disadvantage is that it is a software emulation of these devices, not real chips, although the sound is pretty close. You can checkout video by Retro Erik or contact me for any questions regarding this device. You can buy it too from Serdashop, or build one yourself.
If I were you, I would buy either OPL3LPT if you want real AdLib sound for games, CVX4 if you want to listen to MOD files and demos or/and picovox if you want to try all of it and experiment a bit.
Hope that it cleared things up a little bit. In case of questions, direct them here so that anyone can answer them. Have a nice day.
