First post, by Shreddoc
Forgive me if this thread already exists somewhere, but I can't see it. After completing a modest version of such a build last weekend, I thought there must be many of us doing this sort of thing, and it would be nice to see them gathered in one place.
Obligatory crappy photo:
I wanted to do it cost-effectively, by re-using things I already had. Therefore I limited my purchases to an RPi 3A+, and a $3-including-shipping 5102 DAC from Aliexpress. A total outlay of <US$50.
The recycled Case : A shithouse ($10-20) Aliexpress amplifier I got for testing some time ago - it's case, while nothing special, is the most worthwhile piece of the whole deal, the electronics being rubbish. Semi-gutted it, by depopulating all it's boards components.
But I left the bare board in place, so I could re-use it's external fittings such as switch, power input socket, and 3.5mm audio socket - saves me needing to rebuild my own. I drilled the old board out at a handful of strategic places to ensure signals from those re-used ports couldn't wander through the old board. Then layered a thin piece of wood over top, onto which the RPi was secured.
Power was wired from the case's DC input socket, directly to the back of the RPi board - the PP2 (+) and PP5 (-) solder points - via the case's switch. This way, I can use any-old of the many 5V 2.5A DC power bricks I have lying around from my Pile-of-ADSL-routers years, rather than having to spend more hard-earned on a special Pi-USB3 power brick. The Pi's audio out is similarly wired to the case's 3.5mm socket.
A USB extension cable neatly coming out the back of the case provides a port for my existing MIDI-USB cable, which shares my DOS PC's MPU with my real SC-55 by way of a Serdaco DB15 splitter.
I have not bothered with extra switches or even screen functionality, as those are not important to me - I simply wanted a tidy, convenient physical box that I can easily switch on when I need MT-32 sound.
Job done. Nothing special or fancy in any way, but I'm really pleased. And very thankful to Dale Whinham, the author of mt32-pi, and indeed to the makers of the excellent RPi itself, and to Roland for making such a great device in the first place, and to the skilled composers of the MT32 soundtracks we all love, and which I finally (after 30 years) get to fully experience in a fun, convenient way.
THANK YOU!!! 😀