Resources:
INTRODUCTION:
It’s been bugging me for a while now what all of the additional solder points on the Volca PCB are for and surprisingly there is just not a whole lot of information available online beyond the same handful of “traditional” mods (Midi out is really the only one I see mentioned anywhere for the kick… I was kind of shocked no one else has ever done a write up about these other points!). So I decided to venture on a bit of a destructive journey to attach a wire, pot or port to every conceivable point I can on my Volcas (Kick, Sample, Keys, Beats and Bass) fire up the oscilloscope and see what does what at each of these seldom explored points.
Let’s Kick It
I wanted to start with the Volca Kick for a couple of reasons but hands down the most obvious one is that it is simply my favorite of the brood. I picked this guy up as a freebie alongside a Korg Monologue a couple years ago and was honestly not expecting much. It was rarely mentioned amongst the modding hobbyists and the fact that Korg was giving them away for free across all of their retailers didn’t exactly instill much confidence in me but hey, free is free so I figured what the hell? I wanted a monologue anyways so now seems like the right time.
The VK is, as it’s name implies, a Kick Drum creation platform and to that end it is very easy to create some thumping bleeps and thunderous bloops with it’s included recreation of the legendary MS-20 VCF. It can really hit hard with the right settings and also features a very unique touch effects system that allows you to apply, tweak and remove effects on the fly while a pattern is playing. Unfortunately it seems like most Volca enthusiasts weren’t drawn in by the idea of a box that “only” makes kicks and Korg really did miss the opportunity to make it appeal to a broader audience by marketing it the way they did. In practice the Kick is so much more than a one trick pony and spending even a few minutes with it is enough to realize that it can be used to craft some truly monsterous low end bass tones, warm and punchy mids and sparkly bright high end that will find a fit amongst almost any composition. If you own one then you most likely already know all of this but if you are on the fence about what your next box should be, the Kick really does hold its own alongside the Keys, Beats and (in my opinion) is a worthy consideration against the Bass for a low end powerhouse.
As I previously mentioned though, when it comes to modding ,the Kick has not received much love beyond the midi out mod that all of the other Volcas can also be outfitted with. There are some very intriguing access points on its PCB though that deserve to be examined. So without further ado, let’s dive into the Fresh Prince of the Volca line, the VKick:
Volca Kick, The “Fresh Prince”
The Volca kick has two points that really immediately fascinated me the first time I opened it up which are the points marked “Output” and “Input”. I assumed these were for accessing the filter but it also features a point marked as “VCF Out” so maybe it something completely different? I will take this moment to tell you that while I have been doing the twisty twist of the magic knobs for about two years or so now, there is still a ton that I am not very knowledgeable about so if I say something obviously stupid feel free to correct me and I will add any edits to help future visitors not fall into any traps. Also, with that admission of amateurism, please use my findings as a single source amongst many before attempting any of these yourselves!
The Outtie and The Innie
The Output point I wired up to a 3.5mm jack and connected the other end to a ground point on the board. Looking at the signal coming from this port when a pattern is playing shows that it closely matches the signal coming from the headphone jack output. Initially I thought that this might be a line level output but once I determined that it was barely outputting 2v I deemed it safe to plug it into my mixer at low level and was pleasantly surprised to hear, what I am guessing, is the direct output from the filter that is not passing through the other controls on the Kick. I will upload some audio in the next couple days but the sound is impacted by sweeping the filter but it is a very raw signal and does not seem to be affected by any of the other parameters. (Future edit spot for “hey dummy it’s called a $$$$$”)
So that is pretty nifty for when I inevitably make these patch points to use between the different Volcas very soon. The next one I was interested in exploring was the input but this one was a bit perplexing. My oscilloscope has a very rudimentary square wave generator and so I set it at 1v and increased in short increments to see if I was passing an external signal through the filter but it did not seem to be the case. The sound did travel through the Kick and come out the headphone jack albeit not affected by the filter in any way. If a pattern was playing on the kick at the time it would interrupt the sound of that pattern anytime another signal was sent through the input. I also tested feeding a signal through the input and monitoring what came out of the output but unfortunately this does not seem to have any impact at all or pass the input signal through the MS20 filter like may be assumed.
The “Very Careful Frank” Output
Next is the VCF out. This one is self explanatory however my inexperience with modular-ly-ish synth territory shows in that I am not entirely sure what to do with this. I wired it up to a jack and scoped it and it showed a consistent signal matching what the filter was doing outputting around 2v again and upon sending it through my mixer, Korg really nailed the labeling because yep, it’s some post filter goodness but I have not yet had the aha moment with regards to what to do with this in a larger patch scale. Suggestions are definitely welcomed!
Uncle Phil Has More Secrets
There are three other points worth noting. The first are two “reset” points which I have not messed with yet although I would be willing to guess these are either for resetting the internal memory or resetting the unit in general. It’s a little harder to follow the traces on these to tell with any certainty where they end but once I rig up a safe way to test them I will report back. The other one is a 5v point which does in fact output 5v but it seems a little peculiar that Korg went out of their way to call attention to it. It is connected directly to the last mysterious solder point “bias” of which I am also unsure what purpose it serves. Bias certainly leads me to believe I am going to want to connect it to a potentiometer but when I went to grab one from my parts drawer I was tapped out until the Amazon man delivers some more on Monday. If anyone has some insight regarding what bias may refer to in this context I would be very interested to hear what I need to be looking for. Researching online didn’t turn up many clues as to how it might be being used for the Kick.
Let me know of any suggestions or questions you want to know or would like me to explore while I am Frankensteining my way through these little beasts! I’ll share some audio I captured and some more pictures of I get time this weekend and we can investigate together on these!
~~Audio Samples~~
Edit: quick note, excuse the awful soldering job on those midi input pads! A year and a half ago I attempted to do the midi out mod before i had a temperature controlled soldering iron or the correct tips and burnt the hell out of those pads! I don’t have a use for them for this project as I am going to be hijacking the midi input port from inside for something else.