Mainbow Video Synth DIY kits back in stock!

I have nothing to do with the company. But have been waiting to buy one of these kits for like a year.

very fairly priced for such a cool module.
it will probably sell fast, over half gone within 24 hours

my bad if posted in wrong area, I kinda lurk here randomly.
keep making art!


Dang, just missed it!

Been trying to get a Mainbow for a minute!

Oh well, next time.

I was lucky enough to score one of these excited to mess around with it nervous about building it

Have you built much before? This kit seems fairly easy, but I have built a LOT of stuff.

If you haven’t built a lot of things what I find really important is using a good tool. Those cheapo $15 soldering irons are trash. Something like a Weller WLC100 at the least is a great option imho. Some decent solder from Kester would also be helpful. Specifically the 63/37 blend is what I use in .031 size for through hole.

If you need to build some confidence it can be really helpful to buy some practice kits for little LED stuff. Sound reactive kits, LED flasher/chaser lights etc. Lot’s of inexpensive practice boards exist too. Or just buy a couple pieces of strip board and soldering resistors to it. You can definitely build confidence that way without worrying much about messing stuff up.

Also, so long as you can take good photographs with natural lighting people should be able to help you troubleshoot in the event you get a failed build.

Soldering is an awesome skill to learn, best of luck with your kit!

…the Chroma Cauldron kits that i saw/worked on until now were extremely well prepared - nothing left to chance!..

…each part of the kit was separately glued to a page with the description of the part below it, there were printed build-instructions included with the kit (no searching online for the correct build instructions) and the PCB-layout was generous so that placing the parts and soldering them in was no problem…

the new manual for this kit is pretty extensive too. (80mb file)
lots of tips for troubleshooting, schematics explained and lots of detailled instructions

EDIT: The below issues mostly cleared up after eliminating a group loop between my projector and the synth.

I spent some time with my preassembled Mainbow last night. It is my first analog video synth so it’s quite fun to see how four VCOs can make wild patterns!

I’m having difficulty getting anything close to a circle, however. The demo shows very clean circles should be possible, but mine are more like bumpy rhomboids:

I also have thin diagonal banding and a slow scrolling dim band. There’s some other issues which I am chalking up to noobiness (for now), but these things seem like nothing to do with my patching. I’m going to try a different power supply and maybe get an HDMI capture setup for better footage. Any other thoughts?

BTW, here’s the manual for v2.

…there seem to be a few DIY-kits available on Etsy right now:


I just got one!! SO HAPPY!!

I received my kit and it most definitely looks like a daunting task to build it I have a friend it’s going to help he has a nice soldering gun and has done it before so I’m going to learn any suggestions on a Euro rack I’m thinking the Nifty case and with the extra slots that I have I’m going to get the VGA converter from Lo-Fi future hopefully a Hypno at some point and syntonies 1 and 2

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The Nifty case has a lot of bad reviews, maybe check them out before buying it. Basically a lot of people have had issue’s where all the extra features like midi to CV or the built in power supply crap out and they have to deal with warranty exchanges. Just a heads up -

The case is definitely an expensive part of getting started. It can be a little easier if you DIY the wood box part. Decent rails like tip top z rails will add a bit to the price but they are made very well, nice lip on the edge of rail which keeps the module in place. Got one of these cases in a trade with all the electronics removed, because the seller ran into that issue.

It’s possible that the company updated the design but it all looks kind of inexpensively manufactured (the case is super solid, but the modules probably extremely bare bones design wise).

Good luck on your build with the friend, awesome skill to learn!

Hi!! Just built mine and I have to say to those who are looking for a case. 4MS does well!

Can’t wait to make something beautiful with this fucken incredible piece of gear!

Thanks to ChromaCauldron for helping out with the build and thanks to @hugdealer for letting us all know!

I finished assembling my Mainbow kit last weekend after 4 sessions of ~1.5hr each. It was a hefty kit but incredibly well documented and easy enough to assemble in the order provided, if tedious for all the parts. No big deal on that, but it’s good to be aware how much time you will spend on this!

I’ve been enjoying the result greatly. With 4 function generators each able to generate 1 of 7 wave forms on the X or Y axis, or to scroll, or use an LFO, which are patchable into themselves or each other, it seems very versatile. I spent hours last night messing with it and could have easily gone longer. I have a lot to learn here about how to patch this, as there are quite complex outputs possible it seems.


I love your cat

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Thanks! His name is Pixel. He’s my music buddy.

I had fun making some crazier visuals the other night, with some camera feedback as well.


As of now there are two mainbow kits left in stock.