Today we install a midi out feature without drilling into the Volca to add an extra midi plug, the midi out “hack points” will be connected to the unused 1 and 3 pin of the midi plug seen in the picture. These pins were soldered to ground however, so cutting the tracks on the circuit board was necessary. The two current limiting resistors are 220 Ohms. Note that the boards are quite dirty from soldering flux from the factory, the flux is not removed cause it actually protects the board.
Here are the cable schematics and a picture of the volca and the cable. I think this hack should work on the other volcas too! The only thing that is not transmitted is playing the keyboard directly, but it will send sequenced notes!
With Dexed you can upload sounds to your volca from a DAW/VST environment, but with midi out you can also send your sounds to the computer! you just enter the edit sound mode and then hit the export button, your beloved sound will then appear on your dexed VST.
Here are some High resolution pictures of the internals for those interested:
Ivar A. blog 
Very Clever! I assume this non intrusive mod can be done to all volcas, right? Also, are the sequencer and arpeggiator data sent through the MIDI out as well? Thanks
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The sequencer is sent over midi yes, both key play and motion rec. The arpeggio will not send 😭. It should work on every volca, however volca kick has some wierd note system.
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what a shame about the arpeggiator!!! How did you cut the ground traces?
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it is a tradeoff, my jdxi has the arpeggiator connected to the keyboard section which means the arpeggiator will not work with external keyboard. But the volca will cause the arp is in the voice section.
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I bit the bullet and did the mod exactly as you show (cutted the traces and added 220ohm resistors). I did not tested it yet, before I wanted to check something. I am getting some resistance between each of the Midi out pins (1&3) and the Midi jack collar (the part that touches the midi cable´s sleeve), 1k between pin1 and the outer ring and 11k between PIN3 and ring. Is this normal? Can you check on yours to see if these resistance values are similar (or if there is any resistance at all)? After cutting the GND traces from both pins and before soldering the resistors I checked for continuity between GND and said pins and there was none (meter read OL), so that´s why I find this weird, but maybe after installing the resistors it makes a path on the circuit that gets me those reading on my DMM…
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Good news for you! I get the same values, approx 1kOhm and 11kOhm. 🙂
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Sorry for late reply, been busy working for the last months. When you connect the resistors the pins will become connected to the logic and the powerline Vd of the volca, you will probably not get infinite ohms to ground wich is the shield connected to pin 2 if im not wrong (it may depend on the midi cable/plug). but Ill do the measurements when I come home today.
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hi, could you show more detail on where to cut ground traces?
also, how do those pins then connect to #5 and #4 on a MIDI out
cable? is there something to know about MIDI cables?
i’m about to do MIDI out on a stereo minijack, find DIN very stiff,
and considering possible damage if force is needed to insert/remove
cable (?)
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Hi. Everything you need to know should be in the pictures if you go through them. You can see the traces with a loupe, they should be at 3,6,9 o clock. Measure after cut to veriy. I buy soft midi cables from thomann, and had no problems with those. I dont think you can break the plug unnless you have kids or go to busy gigs etc. You can also buy 90 degree midi cables that fit better and is more safe. I bought these.
Midi cable
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lol ! i’m looking at it with a magnifying glass ,now !
i can see ‘tags’ coming off those main solder points,
for those 2 pins – i’m not sure i can see 3 for each one,
and it looks *really tight* – one slip and you’re toast.
you do mean those? how do you cut them? with a craft
knife? i think some of mine are out of sight.
it is on that side of the board, that you cut?
i would much prefer to use your method, because i’d
like to do a good midi out to Keys and Bass too.
i don’t really trust a custom-installed DIN, for it to be
solid (i have a load of MIDI cables – didn’t mind the idea
of chopping one to add a stereo minijack to it).
cheers!
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btw, doing volcaBeats – suppose it’s the same ?
what am i removing by cutting these ground plane
connections? these pins are unused, are they ?
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The traces is marked with red dots in the picture with the installed resistors. They are on that same side of the board, not the other side. Cut them with a scalpel or a little knife, or scrape off with a small flat head screwdriver with a good flat edge at the tip (if not you sharpen it). I suggest you practice on some junk circuit boards from computers etc if you can find some.
Also see this link
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ok thanks – do you have a Beats, and is it the same there?
i will try to get a good picture of what i’m looking at here
(no guarantee i can zoom in that far with what i have).
i can see some connection (trace/tab..) on the left-side
connection – maybe all 3 – but on the right side, i can only
see one ‘trace’, at 9o’clock, maybe something at 6, but at 3,
i don’t really see anything, and there’s a group of traces
running up that side that i don’t want to damage. i can’t
actually see any ‘traces’ in the pcb there – do i have to scratch
away to get at them?
what are the 220ohm resistors doing? protection? how do
you select that resistance?
and: any danger putting this output on a minijack? can it
short if you insert the cable while the unit is on? something
i saw on one youtube..
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Traces are hard to see, im not totally shure how it is done on the beats. 220ohm resistors are for current limiting into the photocoupler diode on the receiver side. 220ohm was used based on other volca midi mods that is exactly the same only with a jack plug. With those resistors you can also shorten the midi signal without any damage due to current limiting effect.
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I am very happy with the mod, I´ve made the splitter cable with female ends. After doing this mod is it safe to use a regular midi cable for midi in only? generally I build my own midi cables and just wire the 3 center pins needed. But some branded cables have all 5 pins wired, can I fry something if I use those?
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Hello! On your diagram of the wire, i’ve noticed what on MIDI out pin 2 is not shielded, while MIDI in pin 2 is shielded: https://123fixblog.wordpress.com/2017/06/30/volca-fm/midi/
While in the spec is written the opposite: https://www.midi.org/images/easyblog_articles/414/Screen_Shot_2020-07-18_at_12.20.08_PM.png
And also i’ve noticed what these guys are using 10r and 33r resistor (as in MIDI spec told to do for 3.3V) while you are using 220k (as in spec told to do for 5V).
I will be very grateful if you’ll be able to clarify some of these questions.
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the third link didn’t attached (“And also i’ve noticed what these guys are using”): https://www.usbtri.be/usbtribe_volca.html
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i continued my investigation 🙂
and apparently (http://www.ksadhu.niezba.org/sajty/korg_volca_bass_sm.pdf) at least on volca bass those resistors are already present on original board
also, totally from a different direction – using panel-mountable DIN, which is mounted not inside the panel, but outside of the panel (something like “Lumberg KGV 50”) would allow to fit it between MIDI IN and program (since it’s mounted outside, it need drastically less vertical space)
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Hi! sorry for answering late. I used 220Ohm cause I copied from another guy doing the mod. The resistor is there to limit the current to the diode in the optocoupler at the receiver. I had no problems with my setup so I did not think of the value more in depth. Lowering the resistance adds risk and in my opinion only needed if it is not working. And if doing so I would most likely have studied the circuits in the volca more in depth to see if the resistor was already there from the factory.
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Hi really nice! the resistors are not needed as there are already 2 47 ohm resistor on the board (and they are ok with the 3.3 v supply)
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