Are you sure that your 9V DC adapter has the right polarity? Looks for me from pictures of the MT-32 that outside of the jack is + and the inside is -.

Yes, check the polarity, it should be CENTER NEGATIVE. The advice of your seller missed that important detail ("any" is just not true). I hope your MT-32 is still OK.

Chiming in to agree with this. I had to take a "standard" 9v 1A adapter and reverse the polarity by swapping the wires to make it compatible. Adapters that come prewired with the correct polarity are rare.

Also there are adapters with the correct polarity on ebay which are grossly overrated as to specs. I bought one such adapter and it wouldn't power on a MT32 correctly. Any current draw over 200mA would make the voltage sag below 7.5V, even though it was marked "9V 1A". Lesson learned.

( I had at the time contacted the seller and let him know about the problem - but as far as I know he still lists those adapters on ebay as "MT32-compatible")

Thanks, I've inspected the part you guys mentioned, and that seems to be the case. Assuming my MT-32 still works, do you think this adapter would work?
https://www.amazon.com/AC-DC-ADAPTER-9VOLTS-N … R/dp/B00ATDXBAY

Flying Nosehair wrote:

https://www.amazon.com/AC-DC-ADAPTER-9VOLTS-N … R/dp/B00ATDXBAY

No, that one is rated 500mA, while the Roland MT-32 requires 650mA. You can use one with higher rating than that, e.g. 1000mA or more (but stick to 9v).

Reading stamasd's post above, it'll be worth it to spend a bit more to get good quality one. The Roland ACB-120 is the original/reference for your region (120V~60Hz), so try to get as close to that one as you can.

As for the pin, I don't know the exact dimension offhand (EDIT: whatever the Roland ACB-120/PSB-1U/PSB-120 specs says!). I used an interchangeable one (with reversible polarity as well), so I just picked the most fitting one. It is a switching adapter though (as the many other cheap small versatile adapters on the market) while the larger ACB above is linear, which should give the least noise.

Well, OK, what about this?
http://shop.rolandus.com/p/ac-adapter-psb-1u- … ack-120-aci-120

Yeah that Roland PSB-120 seems to be the official/"genuine" replacement for the ACB-120, so it's a safe choice though a little bit expensive. You will be able to use it with SC-55/55MkII as well.

(If somebody could offer a better quality item at a cheaper price, I'd like to know as well)

OK, I've just ordered it. I'd like to thank everyone who responded. I would have never thought of checking those polarity symbols on the objects. Next time I'll scrutinize electronics much more carefully and maybe even ask here first.

I use a "universal" adapter from Radio Shack that is rated for 1500mA I think; one of those that have a voltage selection switch (this one goes from 3 to 12V) and replaceable connectors at the end; I set it for 9V and selected the connector that would fit the MT32, then inserted it in the socket at the end of the adapter cable in such a way that it will give me the correct polarity for the MT32. That socket and the connector itself are keyed so that you normally you can't insert it backwards, but with a little bit of work it's possible. 😀
I paid around $16 for that adapter a couple of years ago. I think they still sell it, it's called adapt-a-plug or something like that.

OK, I've just tried it with the adapter from rolandus.com, and the MT-32's display lit up. I also tried adjusting the volume knob and saw that volume setting goes up or down accordingly. I'm taking all that as a sign my MT-32 is a-OK. However, when I try to use it for SQ3, I still get no sound. In DOSBos, I've set the sound driver to MT-32. In ScummVM, I've checked "True Roland MT-32" in the MT-32 tab, and I don't get sound in either. What am I doing wrong?

Good to hear your MT-32 still working. 😀 I think it must have some level of protection against reversed polarity.

I haven't tried using it under Windows 8, but here are some suggestions to make it easier for others to help:

1) firstly, those ebay transaction links won't work for others except maybe you and the seller, so we still have no idea what you are using to connect your MT-32 to your PC
2) please give a quick schematic of your connections (photos may help)
3) next, steps that you have done -- incl. for example, has your USB to MIDI cable/device been detected properly in Windows 8?

I hope these photos will fulfill the first two requirements:
https://drive.google.com/open?id=12_8BkwH-Q4b … zr5fF2qgBCBV43w
https://drive.google.com/open?id=15yCROBJmUnW … bKwyWLaTG1xCGiQ
https://drive.google.com/open?id=1WWmVQEr_cg6 … MTSCBMe9CEL3Etw
https://drive.google.com/open?id=1amzbz0rTVjI … xsAf0FVZkeARkPw

As for what steps I've taken, well, the USB to MIDI cable/device apparently has been detected because Windows gives that sound when it detects something that's just been plugged in.
These screenshots show what I've done in DOSBox and ScummVM:
https://drive.google.com/open?id=0Bx9mXSLrdLZ … NjZ0aVZPYjA4QmM
https://drive.google.com/open?id=0Bx9mXSLrdLZ … M3o1UkZRYy1VM3c

OK, first thing that jumps out: From your ScummVM snapshot, you enabled both "True MT-32 device" and "Roland GS device (enable MT-32 mapping)".

Selecting both like this is intended for if you have a GS device (e.g. SC-55/SC-55MkII/SC88 or SCB-55 daughterboard) and you want to use it in MT-32 mode. Since you're using a real hardware MT-32, you have to uncheck the latter and keep only the "True MT-32 device" enabled.

The guide here is for an older version, but you can see the explanations under the "MIDI tab" section: link.

EDIT: let's focus on ScummVM for now -- in the Audio tab, "Preferred device" dropdown menu, what do you see? (Don't use the "MT-32 emulator"!)
Do you see the "UM-1" like from the DOSBox mixer /listmidi command? If so, choose that one.

Same in the MT-32 tab also for the "MT-32 device", choose whatever that represents your USB-MIDI adapter (your Edirol/Roland "UM-1"ex, or maybe "USB MIDI Adapter #1")

[For DOSBox, you will also have to set your Dosbox.conf to use your "UM-1" device (midiconfig=3 in your case) if you haven't tried it already,]

I forgot to mention I set midiconfig to 3. Well, I've just done what you suggested in ScummVM, and I STILL don't hear any sound.

Do the lights on the mt32 show any activity? If not reverse the midi plugs on your mt32 (adapter midi out should go to midi in on your mt32).
If there is activity the midi part should be fine and the problem is in your sound setup or the mt32 sound output.

That's right, how are the screen and the MIDI Message LED on the MT-32 unit? If there's activity the green LED should light up (or blink).
Also how's the LED on the USB-MIDI adapter itself?

To simplify your testing, you can put only the right plug into the MT-32's MIDI IN (MIDI OUT not necessary).

Also for testing purpose, connect audio line out from MT-32 straight to an amp/receiver then to speaker or headphone (in other words, not going through a PC soundcard).

Another point worth checking is there _might_ be a specific driver needed for the OS that you have to manually install to use the device.

Btw, I just watched this video where the same USB-MIDI adapter is used (EDIROL UM-1EX):
https://www.youtube.com/watch?v=UcXBZwKhqi4

Well, as the photos I've taken show, the LED display for my MT-32 does indeed light up as does the USB light for the USB EDIROL UM-1EX USB-MIDI adapter, but the the two lights labeled "MIDI OUT" and "MIDI IN", respectively, do not. I'll have to obtain an amp/receiver and speaker or headphone or what-not before I can try out that piece of advice. I'll also start hunting for any drivers I might need to make this work.

Incidentally, that YouTube video is what made me decide to get that USB-MIDI adapter. 😄

Hi Flying Nosehair (what a name 🤣),

This video does a nice job showing the MT-32 at work: https://www.youtube.com/watch?v=pMXagi-RofI

I need a new USB-MIDI adapter myself, and skipping the $5 cheapos which are likely to have some cost-cutting measures (as pointed out by gdjacobs in another thread), I think I'll cough up the $$ and get a name-branded one. Looking for the same thing but all I see on sale (local and brand new) so far is the newer "UM-ONE MkII".

P.S. I should include here for future reference -- there's no "official" Win10 driver for the UM-1/2/3 series (~S/X/SX/EX) but the Win8 driver can be used after a little mod as described here.
Trying to trick musicians into buying new adapters, are they...

OK, I think the lack of a driver for the USB EDIROL UM-1EX USB-MIDI adapter is the problem. Unfortunately, my drive has some encryption that prevents me letting my computer accept unsigned drivers. I"m using my laptop from work. Oh, well. I guess I'll try with my personal desktop when I have the chance this December.