That's a nice clean design, I do recommend that you consider adding buttons though. Otherwise you can't switch from MT-32 to soundfont mode, unless maybe you use MT32-pi-control software.

Here's what I've been working on for a few weeks now - my MT32-pi case which is designed to look like a shrunken regular MT32, but with the bigger 20x2 LCD.

IT's been designed in Fusion 360, but the DAC and MIDI input PCB are currently just on some PCB stripboard that I knocked together. Digitising the physical objects is time consuming work, especially when a print of the top and bottom parts takes 6 hours each. The DAC's audio jack doesn't fit right for instance, but it's close enough to work.

The Pi3 is screwed in there to be an MT-32PI forever, but on the underside I can get to the micro SD card to swap it out, and the MicroSD card can't fall into the case (very annoying when that happens).

The front wouldn't look right with the 3d printing layer lines, and my attempts to print text with the 3d printer didn't work out, so I used my Brother QL700 label printer to print out the matte paper label, and the glossy plastic label. The end result looks pretty fantastic to me, but I'd love it if there was a better way to print the matte front part. I Was thinking maybe a PCB with no traces on it, in a black matte finish. That would be cheap-ish and the silkscreen would work perfectly for the button labels.

Something I'd like to look at next is making a PCB that doesn't sit on top of the CPU so it can cool better, there's room in the case for that. But this one works and I can use it now 😀

Excellent thread. Dale deserves more publicity for his outstanding work on github.com/dwhinham/mt32-pi

I have to admit it is little embarrassing to post mine after Thermalwrong professional work above, but here we go...
I consider this work in progress. Needs a paint job and proper labeling.
I had old unused TV set-box laying around. Entire implementation is based on goal to reuse it. Not only box itself but also part of unit old motherboard mainly for convenient barrel jack for power and RCA ones for audio access. I left all controls for back side because I wanted to keep front side stealth clean look.
I'm using it in tandem via Yamaha MU50 midi pass through connection.

Guts

Back

Proof of concept of LCD bleed light utilization.

I'm still waiting for sd card extension cable to arrive so I can extend convenient SD card swapping capability to back.
If it turns out not to be stable solution I will probably cut out access bay for SD card access from bottom.

I meant to say in the 'what retro' thread, I think your one looks really excellent too, the backlit logo is a really nice effect 😀

Also, seeing your one all put together spurred me on somewhat, this has been brewing since mid 2019 when I found out about WavePi, then MT32-Pi.

I use an SD-card extender cable for one of my PC builds and it's been working just fine with that, I think the protocol it uses is fairly tolerant of extension.

For anyone wanting to make custom labels to match the MT32's font, there's a free truetype font called TR909 that seems to be perfect for the era of Roland products it's from.

I've been meaning to post some pics of mine for a while. I have an old IBM Pentium 90 that ive been using for Dos gaming. I installed an ESS Audio drive sound card and built the clumsyMidi interface board with a break out screen and buttons. I modified the cover for the lower drive bay with the use of a dremel and then wired the Pi and all the connections internally. So now the MT32-Pi boots up with the computer and I can control the soundfonts from the front panel.

Here my little Project:

greetz
Paddy

That looks cool! I really like the fancy buttons, and how tidy the boards are in there, along with an AC power supply, nice 😀

Really nice builds in here, all around. But I especially like ratsflif's build, a 5.25" bay mounted MT32 is such an awesome idea!!

newtmonkey wrote on 2021-04-15, 10:29:

Really nice builds in here, all around. But I especially like ratsflif's build, a 5.25" bay mounted MT32 is such an awesome idea!!

Ditto.

I couldn't be wrong, but I think some semi-professional soundcards stored MIDI daughterboards (WaveBlaster, DB50XG etc) in the bay.
The Terratec/Promedia EWS series was among of them, I believe.

Anyway, this is no critique. I simply mean to say that ratslif's approach is professional! 😎

Late-April 2021 updates about my amateur builds:

My initial build (shown above) - "retrofit the components into an existing redundant item's case" - succeeded by re-purposing junk to cheaply make a clean device which had the no-frills functionality to Just Be An MT-32. In that respect I'm happy with it, job done. However I couldn't help thinking of the missing functions it didn't have : the switches, the rotary encoder, the screen, and all the software capabilities hidden behind.

After looking over people's projects, it's obvious a 3D printer makes the physical build work vastly easier - it's hard to compete with Machined Perfection! However, I've personally found the-fact-I-don't-have-one to be an irritating barrier to entry in that respect. There's also a certain satisfaction involved in manual building the 'old-fashioned' way - hacking holes in prehistoric-era plastic boxes like a caveman!

So, just for fun (+ a grasping want to have the darned thing!) I thought I'd see how such a <$10 Plastic Jiffy Box onion-on-the-belt(tm) hand build went...

The components ) :
RPi3A+ & PCM5102A-DAC;
Plastic Jiffy Box of approx 20 x 10 x 6 cm;
Basic electronic components: LCD, switches, rotary encoder, etc - some of these are ones I already had at home.
Total Cost US$75 ballpark upon reflection this is vastly overstated, even $45 would be heaps (the confusion exists because I'm in the southern hemisphere where things are hard to get and expensive and shipping and stuff, and I'm mentally converting currencies)

After finishing the build and enjoying some MIDI playlists through Falcosoft MIDI Player on my Windows 98 machine, I thought: "wouldn't it be cool if I could have a MIDI playlist where (say) the Doom music plays via an SC-55-alike soundfont, and then the Shinobi soundtrack plays back via a retro soundfont, and then some other 80's game tunes play back via MT-32 mode... without having to touch the device!".

Hence the idea to make a set of rudimentary MIDI files, one for each SYSEX function supported by the MT32-pi. That idea is now implemented and tested successfully, with only the negligible trudgery of tidying-up-the-files remaining.

My getto MT32-PI hat. MIDI In and DAC output only, built cheap using components from rsonline, altronics, ebay and jaycar.

Because it is really easy to spend more money making a cool MT32-PI then it to just buy an original MT-32.

In fact, I have a RA-50 in the mail (basically a CM-32L with arranger hardware on it). Will need a minor hardware mod to make it act exactly like an MT-32.

Output is damn sexy with very good SNR.

https://canthearu.com/mt32-pi/Monkey%20Island%20-%20DAC.flac

canthearu wrote on 2021-05-01, 02:47:

Because it is really easy to spend more money making a cool MT32-PI then it to just buy an original MT-32.

In fact, I have a RA-50 in the mail (basically a CM-32L with arranger hardware on it). Will need a minor hardware mod to make it act exactly like an MT-32.

Ah, judging by this and your other post, you're obviously OCAU's rugger! Feared wielder of the ZD-915!

Well, as the buyer of the one RA-50 ever mentioned in 20+ years of OCAU, it's easy for you to say that about comparative costs. 😉 or, "you lucky bastard" is what I mean to say 😀 Maybe if I wait another 20 years there'll be a second local-friendly LA-Synthesis module hit our public marketplace. Otherwise, most of us in these parts of the world have no such luck...

In any case, I updated the rough cost in my post as I'd completely overstated it - the components added together are obviously more in the US$40 range if bought in the US, or a bit more if you're overseas-like-us. Around 1/3rd your rare bargain.

Not that they're particularly comparable - different types of project e.g. for some the "doing" is part of the win. But then with all the PCI slots you've desoldered, I'm preaching to the choir there, man! I still hope to have a real one one day, but chances without severe wallet-hurt are increasingly slim, especially in the Southern Hemisphere where almost everything comes with a $50-100 postage cost, plus 10-15% GST upon import.

Shreddoc wrote on 2021-05-01, 11:36:

Ah, judging by this and your other post, you're obviously OCAU's rugger! Feared wielder of the ZD-915!

Yep, sometimes I wonder if the price of all the tools will ever get paid back with the stuff I do .... but the journey is half the fun and saving hardware is worth it.

Shreddoc wrote on 2021-05-01, 11:36:

Well, as the buyer of the one RA-50 ever mentioned in 20+ years of OCAU, it's easy for you to say that about comparative costs. 😉 or, "you lucky bastard" is what I mean to say 😀 Maybe if I wait another 20 years there'll be a second local-friendly LA-Synthesis module hit our public marketplace. Otherwise, most of us in these parts of the world have no such luck...

I will accept that I am a lucky bastard in this instance. But my warning wasn't really based on getting that bargain.

Shreddoc wrote on 2021-05-01, 11:36:

In any case, I updated the rough cost in my post as I'd completely overstated it - the components added together are obviously more in the US$40 range if bought in the US, or a bit more if you're overseas-like-us. Around 1/3rd your rare bargain.

I'd put the cost of parts for my bare hat to be more around the $100 AU or so, once you take into account RS online's crazy delivery charges, that I have to source from multiple places, the fact that I have to order extra parts of almost everything, since getting 1 of isn't possible or wise. My unit cost would drop dramatically if I was making many of them, but as a 1 off project it became quite expensive.

Then there is the cost of tools, you need at a minimum a good soldering iron. For some of the complex builds on this page, you also need a 3d printer, which would cost you just as much as getting a MT-32 at ebay pricing. Sometimes I get the feeling that I spend just as much money avoiding paying the higher pricing on ebay as I would if I had just swollowed my pride and plonked down the cash in one go 😀

Shreddoc wrote on 2021-05-01, 11:36:

Not that they're particularly comparable - different types of project e.g. for some the "doing" is part of the win. But then with all the PCI slots you've desoldered, I'm preaching to the choir there, man! I still hope to have a real one one day, but chances without severe wallet-hurt are increasingly slim, especially in the Southern Hemisphere where almost everything comes with a $50-100 postage cost, plus 10-15% GST upon import.

Absolutely, I have a lot of fun thinking through the routing of parts, and sourcing and assembling everything. I bet I would have a ball if I had a 3d printer and were designing a case for my monstrosity 😀

As for the cost of parts off ebay for us southern hemisphere types, yep, it is shockingly painful. That "cheap" PAS16 I bought, ended up costing $65 AU after postage and GST and doesn't even work ..... will have to buy a hot air station and see if it is simply a bad solder joint (as it does start working when cold, then dies after about 10 minutes)

Edit: My ultimate MT32-pi project would be an ISA card that has an internal ribbon connection to the wavetable header on a sound card (or somehow connects directly to HardMPU card) and mounts the DAC I used along with a Raspberry Pi-3A embedded board. This could output sound directly back to the soundcard.

canthearu wrote on 2021-05-02, 00:56:

Yep, sometimes I wonder if the price of all the tools will ever get paid back with the stuff I do .... but the journey is half t […]
Show full quote

Shreddoc wrote on 2021-05-01, 11:36:

Ah, judging by this and your other post, you're obviously OCAU's rugger! Feared wielder of the ZD-915!

Yep, sometimes I wonder if the price of all the tools will ever get paid back with the stuff I do .... but the journey is half the fun and saving hardware is worth it.

Shreddoc wrote on 2021-05-01, 11:36:

Well, as the buyer of the one RA-50 ever mentioned in 20+ years of OCAU, it's easy for you to say that about comparative costs. 😉 or, "you lucky bastard" is what I mean to say 😀 Maybe if I wait another 20 years there'll be a second local-friendly LA-Synthesis module hit our public marketplace. Otherwise, most of us in these parts of the world have no such luck...

I will accept that I am a lucky bastard in this instance. But my warning wasn't really based on getting that bargain.

Shreddoc wrote on 2021-05-01, 11:36:

In any case, I updated the rough cost in my post as I'd completely overstated it - the components added together are obviously more in the US$40 range if bought in the US, or a bit more if you're overseas-like-us. Around 1/3rd your rare bargain.

I'd put the cost of parts for my bare hat to be more around the $100 AU or so, once you take into account RS online's crazy delivery charges, that I have to source from multiple places, the fact that I have to order extra parts of almost everything, since getting 1 of isn't possible or wise. My unit cost would drop dramatically if I was making many of them, but as a 1 off project it became quite expensive.

Then there is the cost of tools, you need at a minimum a good soldering iron. For some of the complex builds on this page, you also need a 3d printer, which would cost you just as much as getting a MT-32 at ebay pricing. Sometimes I get the feeling that I spend just as much money avoiding paying the higher pricing on ebay as I would if I had just swollowed my pride and plonked down the cash in one go 😀

It's true!

But at least this way you have a set of tools and methods that will serve over-and-over for a lifetime in all kinds of situations.

Either way it's a win - first world luxuries, to worry about which exact flavour of rare retro synth we're privileged enough to enjoy! 😀 I'm loving it.

As I say I'd like a real LA-synth hardware, but from a practical perspective I'm more pleased to have a real SC-55 - less monetary value than an MT-32, but unlike the MT-32, there is no "SC55-pi" or similar (with the sole exception of the proprietary Roland SC-VA plugins), and no fluidsynth/soundfont combination sounds truly like (or can cover all abilities of) a true SC.

canthearu wrote on 2021-05-02, 00:56:

Absolutely, I have a lot of fun thinking through the routing of parts, and sourcing and assembling everything. I bet I would hav […]
Show full quote

Shreddoc wrote on 2021-05-01, 11:36:

Not that they're particularly comparable - different types of project e.g. for some the "doing" is part of the win. But then with all the PCI slots you've desoldered, I'm preaching to the choir there, man! I still hope to have a real one one day, but chances without severe wallet-hurt are increasingly slim, especially in the Southern Hemisphere where almost everything comes with a $50-100 postage cost, plus 10-15% GST upon import.

Absolutely, I have a lot of fun thinking through the routing of parts, and sourcing and assembling everything. I bet I would have a ball if I had a 3d printer and were designing a case for my monstrosity 😀

As for the cost of parts off ebay for us southern hemisphere types, yep, it is shockingly painful. That "cheap" PAS16 I bought, ended up costing $65 AU after postage and GST and doesn't even work ..... will have to buy a hot air station and see if it is simply a bad solder joint (as it does start working when cold, then dies after about 10 minutes)

Edit: My ultimate MT32-pi project would be an ISA card that has an internal ribbon connection to the wavetable header on a sound card (or somehow connects directly to HardMPU card) and mounts the DAC I used along with a Raspberry Pi-3A embedded board. This could output sound directly back to the soundcard.

Dude, that's annoying about the PAS. I hope the other guys at least have better luck with theirs. I thought "hot oven reflow" but dunno if you'd want to risk that, especially if you're already looking at the safer and preciser version in the form of a hot air station.

Good idea about the ISA-powered internal+routed MT32-pi. The ultimate in convenience and unobtrusiveness. Maybe if I run out of projects PC-and-otherwise (little chance of that anytime soon, you know how it is) I'll have a blast at something like that for fun.

Shreddoc wrote on 2021-05-02, 01:24:

Either way it's a win - first world luxuries, to worry about which exact flavour of rare retro synth we're privileged enough to enjoy! 😀 I'm loving it.

So true. In the old days, you had Adlib, noisy sound blaster, and by golly you liked it or get nothing.

Shreddoc wrote on 2021-05-02, 01:24:

As I say I'd like a real LA-synth hardware, but from a practical perspective I'm more pleased to have a real SC-55 - less monetary value than an MT-32, but unlike the MT-32, there is no "SC55-pi" or similar (with the sole exception of the proprietary Roland SC-VA plugins), and no fluidsynth/soundfont combination sounds truly like (or can cover all abilities of) a true SC.

Yep, very true. I am looking for an SC-55, but poor right now due to having to replace hot water system and ebay prices for SC-55's are not great either!

Currently am making do with the following soundfont on the MT32-PI:

https://github.com/trevor0402/SC55Soundfont/releases

It still isn't the same as a SC-55, but it is a pretty decent sounding sound font.

Shreddoc wrote on 2021-05-02, 01:24:

Dude, that's annoying about the PAS. I hope the other guys at least have better luck with theirs. I thought "hot oven reflow" but dunno if you'd want to risk that, especially if you're already looking at the safer and preciser version in the form of a hot air station.

Good idea about the ISA-powered internal+routed MT32-pi. The ultimate in convenience and unobtrusiveness. Maybe if I run out of projects PC-and-otherwise (little chance of that anytime soon, you know how it is) I'll have a blast at something like that for fun.

Nah, using an oven would simply burn everything if I ran it hot enough to actually do anything, and it would never get hot enough to actually melt the lead-free solder everything uses. Needs flux and heating around all the main chips and SMD parts to freshen up all the solder connections. That will hopefully reinvigorate it.

Gotta teach myself PCB design. Thankfully Ki-cad isn't 1000's of dollars!

Those are some really cool designs! Especially the mini 3d printed one. And having one in a 5,25 bay would be awesome too!

I'm really happy to own a real MT-32. Prices are going more insane with each passing year.

Awesome thread idea! These are inspiring!

Mine is just a normal Pi3B in an acrylic enclosure with an M-Audio Uno USB interface connected to it.

It's not eyecandy but it works. I look forward to buying a decent prebuilt solution I can just plug my Pi3B into though.

appiah4 wrote on 2021-05-04, 10:27:

Mine is just a normal Pi3B in an acrylic enclosure with an M-Audio Uno USB interface connected to it.

It's not eyecandy but it works. I look forward to buying a decent prebuilt solution I can just plug my Pi3B into though.

Ok, thought I would humiliate myself so:

Still trying to work out some issues I am having with my USB MIDI interface though. The dev is a very kind chap who has been very helpful. I believe he posts at Vogons no?

P.S. Yes the lower button should have been labeled MT-32/SF2 😁

Who needs a fancy case? 😉