I'm trying to remember how its all wired up based on my setup... at a glance the diagram looks about right and seems to check out.

I'd recommend getting a proper high-quality external mixer instead of using switch boxes.

A switch box is fine for sound modules, since only one would be playing at a time.

Mixers are only needed for, well, mixing.

For setups involving just an MT-32 and Sound Canvas (or similar), you can get by without the use of any switch boxes at all.

MIDI:

• AWE64G MIDI OUT -> SC-55mkII MIDI IN
• SC-55mkII MIDI THRU -> MT-32 MIDI IN

Wherewith, you can either soft-switch between the two MIDI modules via SysEx, or, alternatively, power the MT-32 off when it's not the intended target, and mute the SC output otherwise (via button combination) when it is.

Audio:

• AWE64G L/R audio output -> MA-12C "Line" inputs
• MT-32 L/R audio output -> SC-55mkII L/R audio input
• SC-55mkII L/R audio output -> MA-12C "Inst" inputs

Whereby, the line input on the AWE64G is eschewed, and the MT-32 gains analog volume control via the SC-55mkII.

Shponglefan wrote on 2023-08-30, 04:11:

A switch box is fine for sound modules, since only one would be playing at a time.

Mixers are only needed for, well, mixing.

I find mixers to be much more convenient as every game outputs sfx audio at a different level. Way simpler to just turn a mixer knob to get the sfx and midi music level to the balance you like instead of typing in text based sound card driver settings all the time. Volume knobs on modules tend to corrode and cause issues as they age too, so I generally avoid touching them (Roland CM modules especially).

SuperDeadite wrote on 2023-08-30, 10:41:

Volume knobs on modules tend to corrode and cause issues as they age too, so I generally avoid touching them (Roland CM modules especially).

If volume pots are getting corroded they should be cleaned with contact cleaner. Ignoring it could result in the corrosion worsening over time and result in loss of output in one or both channels.

CM64 seems to be the worst offender. Some were so bad that it was easier to just bypass the knob with jumper wires sadly.

+1 for dedicated mixer 😀

Thank you everyone for the great feedback, in case I decide to get a Mixer, which would you recommend? Roland MX-5 for example?

Mixer suggestions depends on how many devices you potentially may want to mix and how much room you have.

Personally I like the Edirol (Roland) M-10MX. It has 10 channels (5x stereo) and is relatively compact.

I use them in conjunction with a 4x RCA switcher allowing me up to 8 total stereo audio devices (modules and soundcards).

SuperDeadite wrote on 2023-08-30, 12:51:

CM64 seems to be the worst offender. Some were so bad that it was easier to just bypass the knob with jumper wires sadly.

I have a few CM modules including a CM-64. I cleaned the pots and have had no issues. Volume control works fine.

And if the pot got to the point of being unusable I would just replace the pot.

Shponglefan wrote on 2023-08-30, 15:00:

Mixer suggestions depends on how many devices you potentially may want to mix and how much room you have.

Personally I like the Edirol (Roland) M-10MX. It has 10 channels (5x stereo) and is relatively compact.

I have two of them in conjunction with RCA switchers allowing me up to 8 total stereo audio devices (modules and soundcards).

Thank you for the suggestion, atm, I will have just two devices connected, of course, there is always possibility for growth so this would work.

I just picked up a Shure SCM262. It has 3 RCA inputs for line level stereo audio and a couple of mic inputs. One of the mic inputs has a line level jack next to it that can be used instead, but I think it's just mono. While a few more stereo inputs would have been nice, this mixer is the perfect size. Also, all of the inputs/outputs are on the back like other rackmount devices. This makes it way more convenient for how my desk is setup. I looked at other mixers, but they were either too expensive, had fewer stereo inputs, or were too big for my desk.

One of the nice things about using a mixer is that I can easily adjust the volume levels by turning a knob. I just need to set the volume once in the OS for each computer or on my midi device. Any time I want to change the volume, I just use the mixer. Super handy. It's also convenient for playing games with a regular sound card for effects and an external midi device for music. While it's not necessary, I find it more convenient than plugging stuff back into sound card inputs and managing it there.

Ensign Nemo wrote on 2023-08-30, 17:22:

I just picked up a Shure SCM262. It has 3 RCA inputs for line level stereo audio and a couple of mic inputs. One of the mic inputs has a line level jack next to it that can be used instead, but I think it's just mono. While a few more stereo inputs would have been nice, this mixer is the perfect size. Also, all of the inputs/outputs are on the back like other rackmount devices. This makes it way more convenient for how my desk is setup. I looked at other mixers, but they were either too expensive, had fewer stereo inputs, or were too big for my desk.

One of the nice things about using a mixer is that I can easily adjust the volume levels by turning a knob. I just need to set the volume once in the OS for each computer or on my midi device. Any time I want to change the volume, I just use the mixer. Super handy. It's also convenient for playing games with a regular sound card for effects and an external midi device for music. While it's not necessary, I find it more convenient than plugging stuff back into sound card inputs and managing it there.

Thank you, good information, I will look into the SCM262 mixer.

Just looked up the Shure SCM262. That is not a cheap option at ~$300 USD. I think that's about triple what paid for my most recent Edirol M-10MX.

Shponglefan wrote on 2023-08-30, 21:45:

Just looked up the Shure SCM262. That is not a cheap option at ~$300 USD. I think that's about triple what paid for my most recent Edirol M-10MX.

I lucked out and got it for $65 used.

Ensign Nemo wrote on 2023-08-30, 22:09:

Shponglefan wrote on 2023-08-30, 21:45:

Just looked up the Shure SCM262. That is not a cheap option at ~$300 USD. I think that's about triple what paid for my most recent Edirol M-10MX.

I lucked out and got it for $65 used.

That's a good deal.

Just looked on Ebay and there is a huge range of used prices for this model.

Shponglefan wrote on 2023-08-30, 22:15:

Ensign Nemo wrote on 2023-08-30, 22:09:

Shponglefan wrote on 2023-08-30, 21:45:

Just looked up the Shure SCM262. That is not a cheap option at ~$300 USD. I think that's about triple what paid for my most recent Edirol M-10MX.

I lucked out and got it for $65 used.

That's a good deal.

Just looked on Ebay and there is a huge range of used prices for this model.

If you're patient and live in a decently sized city, you can often find good deals on stuff like this locally. For stuff like mixers, there are usually a bunch that people are looking to sell one. It often doesn't take long for someone to list one at a good price because they just want to get rid of it. It helps that there isn't a single sought after mixer than everyone is looking for too. A lot of mixers would do the job equally well.

I pretty much avoid eBay these days, unless it's something like a cable. I'd rather be patient and get a good deal locally than buy something on eBay for more than it is worth to me. I probably won't find a killer deal on something like an MT-32 this way, but I've gotten a bunch of 90s computers for around $20 this way.

Yup, I was checking prices and it's expensive; I live outside the US so searching for items outside of Ebay it's difficult for me.
Will keep searching or just go with the Roland M-10MX as to keep everything under the same brand.

If I go with the mixer, and based on my Diagram on the first post, where would the Mixer fit in here? Instead of the RCA Switch Control or the MPU-105 or remove both of these?