i also got a reply from the creator…
“Hi. Running -5v to +5v signals into Mainbow’s inputs will not damage it, but it was only designed to be controlled by 0v-1v signals. Each input responds differently to going outside of this range. The saturation input will flip the hue to the opposite side of the color wheel if you give it a negative voltage. Function generator’s can stop oscillating if the FM voltage is negative.”
i had a couple more questions but have yet to get a response.
kinda answered my own question…i just discovered the world of LZX scalers for Euro to LZX voltage.
so i ended up designing this after your post!
that MAINBOW - CHROMA CAULDRON is crazy!
does that mean you managed to source both the 5:1 and the curtail?
I’ve got an Mainbow on the way and I’d be interested to know more about how you plan to integrate yours with other eurorack gear. I’m guessing that the 5:1 is placed to support feeding modulation from other eurorack sources into the function generators, and the curtail is placed for driving modulation into the hue, luma, sat, alpha controls.
found a used 5:1 on Reverb and snagged the other two on Perfect Circuit.
so…i kinda set it up with external patching access in mind.
things tend to get overcrowded and bunched up if all the INs and OUTs are in one place.
i tend to spread them out when i am designing things for ease of access.
kinda sorta…but again…its with keeping in mind that a horde of cables will be connected to it and i’m not one for trying to dig through a nest of cables to get to a knob or a switch.
i also wanted to have as many connections as possible with the real estate on hand which is a POD64X
Cheers @SPIKE for posting the rack idea, got me thinking about modules to integrate with the Mainbow.
Looking at some of the patch examples in mainbow manual, it seems that it’s not quite as modulation greedy as it appears because of the built in splitters. So if I patch into 1 mod input the other jack becomes an output so that I can take the same modulation and apply it elsewhere. Do I have that right ?
I’ve ordered some pcb’s of the scaler module from the cadet series. There’s not a lot of parts and the components can mostly be found on mouser. Definitely a good idea to integrate converted euro signals into video format though For my mult I’ve got a visible signals ‘video mult’ to build.
spent about an hour with it today so far.
got it to do quite a few things.
but…sometimes i would get it acting a certain way and then after tweeking things for a while i couldn’t get it back to where i started.
that is mostly attributed to the fact that i don’t know what i am doing.
also…i couldn’t get it to do the first patch example where it just makes a circle.
however i did get it to go crazy and do some neat stuff with the audio input.
be aware it does NOT come with a power cable.
you will need to source or make (like i did) a 16 pin cable that has 16 pin connections on BOTH ends.
I think at least at first ‘this is the way’ with video synthesis
I setup the start of my diy 110hp rack today with after testing, an excalibus power supply.
Everything worked, that is Syntonie 7b. 3b and quadrature osc. Fed a composite signal in and had fun.
How do you get rid of the dark block in the middle I wonder? I don’t know what I’m doing either
Thanks @SPIKE for the heads up on the cable. I have some suitable ribbon cable here somewhere.
I’ll give the vid a watch when I’m relaxing later. Thanks for sharing
Oh here’s a pic of the quadrature syntonie on the scope. Notice how the waveform is above the zero volt line as it’s 0-1v signal… That’s about the extent of my ‘deep scope’ knowledge