KORG volca modular

[petesasqwax]

Thanks, that makes a lot of sense. Ultimately it will definitely allow interactions, then, but the accuracy of them will depend upon the way in which each device processes the voltage (what range is appropriate to each device)?

[DoS]

@hardworking

It was from someone who only seemed to sell on eBay, and who doesn’t seem to be there anymore,

Was that Darenager, who’s very active on the Elektronauts forum and elsewhere and who makes a lot of short-run mod boards for all manner of synths etc? I meant to get one of those.

[hardworking]

This is the one, the eBay account was ‘micro.tech’, though nothing for sale at the moment. It’s a shame, there was some very nicely designed cheap and simple stuff, little passive mixers and such. I don’t know the Elektronauts forum too well.

[chalkwalk]

Just a thought I had: if you are running the Volca from a power adapter, you could daisy chain the power supply (break out adapters like that at common for guitar pedals) and route it to the power rails on a breadboard. This would extend the Volca power domain to your breadboard and give you access to a common ground and the 9V supply. Depending how the voltage regulation works internally the power may be more noisy (so some filtering caps may be I order) but it should work. You could even rig up a little board with a 5V regulator on (to run ICs that need 5V) and provide 9V, 5V and 0V rails. I’d imagine this would open up way more possibilities as far as breadboard experimentation goes in a simple, non destructive manner.

[Hlp]

Somone knows if i can safely route the speaker driver wires to a jack in order to patch things inbetween and put the speaker itself to a jack too to make a connection?

I dont see why it should be an issue but i better ask. Reason is to integrate a transformer and i would like to have it in the path even when noodling on internal speaker/sound but not limited to/not hard wired for situations with proper monitoring.

[Shiftr]

I don’t really understand what you’re trying to do. But since the speaker sounds stops when you insert a cable in the headphones out. I think the speaker is just driven by the headphone output. Inserting a jack just break’s connection to the speaker.

[Hlp]

Thanks, that does help. Means speaker on its on jack. It does help patching after the VM out but still use the mobile monitoring.

[Shiftr]

You can probably modify the output jack with an extra wire to have the speaker always on.

[ohm]

I would like to have something like this mod but I don’t trust my soldering skills to be able to pull it off, and I would want all the inputs/outputs converted to 3.5mm. This person did most of them.

https://www.instagram.com/p/CFFIE5JneFG/?utm_source=ig_web_copy_link

[petesasqwax]

This is what I don’t really get. If a user can do this, why wouldn’t Korg?

[license]

Probably for the same reason that almost all the volcas have MIDI out capability but no jack for it: hitting that sweet price point.

[chalkwalk]

I think the problem is more than just soldering. The panel has 50 patch points, each of which takes up about 2.5mm X 2.5mm. A typical vertical 3.5mm port takes up about 13mm X 9mm on the PCB. This means the jacks take up about 18x the area on the PCB. The board is already dense: no amount of soldering skill will get around this. There may not even be space (depth wise) to insert a jack with the port mounted conventionally. This means that the mod would require specific design and consideration for each port (i.e pin patch points weren’t just to save money: they were the only way to keep it small). In other words you will have to work hard and solve many problems to do this on a per port basis.

If you want access to all the ports and controls my suggestion would be to do it by way of a complete replacement of the case with one about 2x the size. Effectively remove every control, patch point and port, and replace them with a panel mount variant. Running leads from all the original patch points.

[petesasqwax]

That’s an excellent idea. I’d overlooked the fact that they have to fit it into the Volca form factor too - which is obviously related to the depth of the unit as well as the width and length.

[chalkwalk]

As a follow up to this, if you look at a tear down (of a stock Volca), you’ll see the unit is made of two PCBs. The ports and jacks (sync, power, audio) all mount on the lower board to leave enough space between the panel and the PCB. Off the shelf/conventionally mounted jacks almost certainly don’t fit between upper board and the panel. This, combined with the large footprint (Vs the small female headers they use) would probably make layout as 2 boards even more tricky (meaning you’d probably need a different case and overall layout inside). I presume it costing more than the other volcas relates to the additional assembly cost (more than extra parts) and needing an extra PCB and new case design would add even more: manufacturability is a big consideration that one off DIY makers don’t have to contend with.

Without the extra board they would probably have to seriously compromise on the number of patch points available which seems like a poor trade off. Overall I think they did about as well as they could given the constraints, though I’d like to see Korg adopt midi over TRS ports, or even midi in and out on a single TRRS for future models to free a little more space.

[ohm]

yeah, that is way beyond what I have the skills to do. The panel mount jacks and pots, I could do but soldering connections to the pcb…no way, the parts are tiny.

It is amazing how much Korg was able to get into the tiny box. That is one of the main reasons I was drawn to it in the first place; its is so small and cute.

Somebody will probably figure out a cool way to do it.

[chalkwalk]

One possibility I considered was a “hat”. A PCB with male headers/jacks that exactly correspond to the panel that you push on top. This would only need the traces necessary to provide the jacks and would be completely non destructive. This poses a few problems that I can see. First of all: how do you access the pots? They could be make accessible directly, but once placed alongside full sized jacks this would be quite inconvenient. You may be able to add knob caps but I can’t really say for sure. Next would be visibility of LEDs; I don’t know that there are any on the panel, but the pots are illuminated and that conveys information you probably don’t want to lose. Finally it may be very hard to install. Getting a couple of rows of headers to line up is tricky enough: getting 50 disjoint header points plus the 5 ports to all line up at once seems very tricky, no matter how carefully you construct it (maybe it would be made in several pieces?).

You might be able to avoid this by having it stand off and installing a rat’s nest of wires in between, but at this point the type of break outs people have been discussing probably make more sense. I suppose you could make one that more closely matches the layout of the Volca and provides jacks for every patch point which you hook up with ribbons (lots of the patch points are in little groups, so it would make the wiring neater). Even then, all those connections would probably obscure the panel and make it hard to access the pots without a lot of careful routing. This also loses a lot of the charm of the device (compact and self contained).

All in all I think making a new case with all panel mounted controls and ports is the only way to end up with something that retains all the usability and consistency of the original. It might be a fun project for someone, but not something I’d be inclined to undertake.

[Shiftr]

@chalkwalk

First of all: how do you access the pots?

I think it’s not that hard. A PCB with male headers that fits flat on the surface of the VM panel. The PCB would extend a bit on the backside of the VM and there you would have 2 rows of jacks.
The idea makes me want to try out if i could design it.

[chalkwalk]

My concern isn’t if they can be touched, but if they can be used easily. Presently the pots only extend a little above the panel. Though the PCB could stand off by only a few mm, (maybe losing 5mm including the PCB) if you wanted to keep the jacks near the corresponding pots (as the pin patch points are). With a relatively large jacks (I mean the entire box), which is around 9mm tall, adjacent to a pot shaft that’s only extending a few mm above the PCB, I think it would be hard to use. Adding a knob cap or other “pot shaft extending techniques” may suffice but I’d be worried about practical usability once patched. I’d love to hear how it goes off you try it out though!

[Shiftr]

Oh wait! It’s already done!

[ohm]

holy hell that looks amazing! where did you find this?