Alternative Volca MIDI Out Mod

Lately I’ve been experimenting with a different way of recording tracks, which is more ‘live’ than drouth was. It relies on having lots of different instruments going together at the same time, and so synching them up properly is pretty important.

I’d run into a problem lately where I didn’t have any way to synch up my Game Boy or other MIDI synth if they came at the end of the chain. The Korg Volcas have MIDI input, but not MIDI output, which is annoying. I knew there was a kit available to modify them to have MIDI output, but it was pretty expensive. After a bit of Googling, I realised that the mod wasn’t all that difficult to do at all, so I decided to have a bash.

Note: This isn’t meant to be a complete step-by-step tutorial on how to do the MIDI out mod. There are lots of sites out there that do a great job of explaining that. This is meant to explain an alternative method of implementing those. Links are in the post.

The best looking one involves adding in an additional DIN connector onto the top of the Volca, which you can find details on over here. I really didn’t fancy taking all of the knobs off and potentially screwing up my synth by drilling the hole wrong though, so hunted about for alternatives.

A few people had inserted a 3.5mm minijack port out, which can be used to transmit MIDI signals. In particular, there was one mod where you simply connected the MIDI out pads to the Volca’s existing minijack sync out port. That seemed like a great option, and I went ahead to do it:

After doing it, I discovered that this wasn’t really ideal. It may well have allowed you MIDI out, but it meant that the Korg sync out no longer worked. That wasn’t really ideal for what I was looking for. Back to the drawing board… I decided to add in an an additional minijack socket to transmit MIDI, and keep the rest of the Volca’s functionality intact. There was a decent tutorial on this here, and I had some experience of this kind of thing from all my Game Boy mods, so it seemed perfect.

Sadly… this too was not perfect. I had a minijack to DIN cable that supposedly transmitted MIDI, but it turned out that for this option to work you really needed to mock up a custom cable. I was too impatient for that, and given that I knew my track record of losing cables, being tied into a single cable for MIDI output seemed to be a bad idea. Hmm.

To check that the circuit actually worked first, I dug out a panel mount DIN socket and wired it up. It did, perfectly. That left me with the problem of where to put the damn thing. There is literally no space in the Volca series for an extra huge jack, unless you were prepared to drill the top plate… and like I mentioned earlier that wasn’t on the menu.

Taking inspiration from the first pioneering Game Boy modders, I decided to drill a small hole in the Volca’s case, wrap the wires in heatshrink tubing to bind them together, and then connect them up to a female DIN connector that would sit outside the Volca – minimising the need for case modification.

Here is what the wires looked like before being hot glued into place:

And here is the final product, with the Volcas happily dancing together via MIDI out:

So there you have it, an alternative to obtaining MIDI out from your Volca without having to resort to defacing the case too much. This is a stupidly easy mod to do electronically; it’s just the case modification that’s a bit of a pain.

For the technically curious, I used stranded wire for the individual connections (for flexibility), and got the female MIDI connector from eBay somewhere. My version could definitely have done with being tidied up a bit, but it does the job. I may do the same thing to the Volca Sample at some point, as it’s exactly the same – just with the solder points positioned slightly differently.

Transforming a Gameboy

One of my work colleagues read about my Gameboy fiddling and kindly posted up one of his old grey DMGs that was destined for the charity shop to see if I could do anything with it. I decided to document its transition.

It was in the kind of standard condition for a used Greyboy of its age. The case was a bit roughed up and the LCD screen had vertical lines of dead pixels at either end. You can make them out below.

First things first was to see if I could fix that, as if the screen was dud, it would only really be worth spare parts. Luckily, it’s a pretty simple job, and before long the screen was as good as new.

With that, it was time to set about preparing the screen to put a backlight in. The old Gameboy screen was always a nightmare to see, so installing a new LED light source is a must. It’s also a tricky process, involving removing the foil back off of the screen itself. One wrong move and you can trash the whole thing. As it turned out, the adhesive on this particular Gameboy hadn’t corroded away, meaning it was a pretty smooth and simple process.

Then I put the Gameboy guts into a new case: transparent orange, which is a colour that was never available for the DMGs back in the day as far as I’m aware.

Next up, I installed a hex inverter chip to ‘bivert’ the screen. The new backlight polarising filter inverts the screen already, and so this step inverts it back to the regular display type, increasing the contrast in the process. It’s fiddly, but drastically improves the clarity. I’m pretty blind, so any picture improvement is a win.

It took a while as I didn’t realise that the backlight kit was missing a crucial resistor, and I had to go through each step to test it all again. A good lesson in not trying to do too many things at once.

Here’s the screen all lit up and biverted.

Next was installing a pitch oscillator that I had had lying about for ages. In other words, a small knob that changes the clock speed of the Gameboy to run faster or slower. What’s the point in that? For games it helps speed up boring parts that you can’t skip, but for music it lets you slow down or speed up things with the corresponding pitch change. Pretty damn cool.

The potentiometer fits into the space where the speaker sits, so it had to go.

I included a switch to turn the pitch oscillator on or off, which turned out to be a bit too big for the case…

I also wired up two RCA jacks for line level audio output. This wasn’t the ideal place to put them, but space was tight because of the other mods. I had begun to install a 3.5mm line out in the same position, but realised that the plastic seemed to be much thicker than in the other model I had done this on, and so the barrel was too short to fit through. RCA it is!

There was a lot of wires in there by this point. Just for fun, I decided to throw in some orange LED lights to give the case a nice glow. By the end of that, it was a bit tricky getting the case to go back together neatly.

At least I used appropriately coloured electrical tape…

So after a good few hours working on this beast, spread across a few days, here’s the finished result:

The case cutting and drilling leaves a lot to be desired, with rough edges obscured by the buttons and pots… But you can’t really notice. Despite that, I’m pretty pleased with the end result. Everything works, I learned a fair bit, and an old Gameboy has a new lease of life.