I want to buy Hardware MIDI module to listen DOOM and ROTT's music better.
Roland SC-88Pro and Yamaha MU80, which do you recommend?? I can't choice ;;;

Why? I would think that using some good General MIDI replacement soundfont in Windows would do the same, and it is free.

For Doom and ROTT - Roland Sound Canvas (and even SC-55 should be more than enough)
For DN3D - Yamaha MU80

I prefer Yamaha but I think that old MIDI music for games was specifically made for Roland and General MIDI compliant cards. But for late 80s - early 90s games you still need Roland MT-32 or software emulation (MUNT is doing great)

DOOM for sure and ROTT I think were both composed for the SC-55, so if you're looking for the most authentic sound you might consider getting one of those. You will have the least issues with a unit that has firmware 1.21. A handful of titles will exhibit some issues otherwise, most of which can be worked around with a simple filter in between.

I got a SC-55mkII and it's noticeably dropping notes in D2MAP05, which is quite strange because it's got more polyphony than the SC-55, not less. Perhaps the song is a very tight fit for the SC-55 and the wrong notes are getting dropped because more can play. This shouldn't be a problem with SC-88 and above, but they don't have exactly the same instruments as the SC-55, if that's what you're looking for. They may well sound better, but that's all subjective. Same goes for the Yamaha I guess.

Oh, and if you can stomach the DRM involved, have a look at Sound Canvas VA which is a SC-8820 emulator. One might imagine that a software solution could be rather more convenient than a hardware module. Unfortunately it's not considerably cheaper, at least for the PC. I understand this is a brilliant replacement for SC-88 and above, but again, not exactly the same instruments as SC-55 if that's important. And it has the issues all post-SC-55 have, like no capital tone fallback (which doesn't affect DOOM or ROTT)

Hmm... I use Yamaha's S-YXG50 soft synth. It sounds better than other software synths.
If MU80 sounds like S-YXG50, I'll buy MU80.

The unofficial one made by Veg? It sounds good, but I still prefer Sound Canvas VA (which is WAY too costly).
If not, please send me a link here or in private.

But Yamaha cards in my opinion have more *push* effect making MIDI music even better.
Beware that you might have issues with old Sound Canvas games like Dune 2 for example, they don't know what General MIDI is but they have better music in place for SC users. However I think I was able to run Dune 2 with SC settings under different MIDI synths, maybe even YXG50, but I'm not sure.

I bought Roland JV-1010 in August 2020, and It sounds perfect for Doom, but sounds not so perfect for ROTT....
But it's acceptable. I think it's good ^~^

Is it possible to port the midi signals out to a keyboard or other hardware that sits outside the computer?

Do you mean that ROTT music is not perfect or you know for sure that some other card sounds perfect in ROTT?

Sure, why not? That's how Roland MT-32 was always able to play music in PC games. Roland MT-32 is an external MIDI module.

ROTT's music itself is really perfect.
But I think S-YXG50 is better for ROTT music
than JV-1010.

+1

The S-YXG50 is probably one of the best GM-style soft synths.

And if you also like to play around in some MIDI editor, IIRC the XG standard has almost 600 sounds, compared to the usual 128 GM ones.

Yes, It is Microsoft GS Wavetable Synth, the Windows default MIDI softsynth, which very sucks.

isnt motherboard soundcard good enough?