Mainbow + recurBOY issues

I recently purchased a Mainbow and I’m having a bit of trouble feeding video into it from a recurBOY.

When I plug the output of the recurBOY into the video input on the Mainbow it shows the video correctly. However, when I turn up the Alpha Symmetry instead of the generated pattern all I see is a grey/white overlay. See video below

What I should be seeing is demonstrated in the demo video. I have feeding video in from other devices and it worked fine, so I’m guessing it’s something to do with the recurBOY/Raspberry Pi? Both the recurBOY and Mainbow are set to PAL (I’m in the UK).

I don’t think Russel Kramer/Chroma Couldron is on here but I’ve also reached out to him via e-mail but any insights anyone here can give (paging @cyberboy666) would be warmly received.

1 Like

Somewhere else in these forums there was a signal issue with the output from a Mainbow that was fixed using a Kramer 104L Proc Amp… Maybe be the Mainbow would play nice with the recurBOY signal if you used a Proc Amp to amplify the signal from the recurBOY into the Mainbow. Just a thought if you have one laying around to try it with and report back.

1 Like

Hi, I have both a Mainbow and a recurBOY, so I tried your test. I do not have this issue… recurBOY into the Mainbow input works fine.

Good to know someone else with a similar rig. Lets stay in touch and trade notes.

1 Like

hi @hellocatfood - thanks for reporting this issue you are observing. having never used a mainbow myself i cant be sure exactly why this is happening, however here is the previous post mentioned about b/w issues with mainbow output into v8:

although this is other way around i guess could be mainbow having trouble locking on to the recurboy sub-carrier…

one thing you could do is test putting something else (like a distribution amp or tbc) between rpi and the mainbow to see if that makes a difference.

it could be that this issue is unique to pal if other users are reporting these two working together ok - so could be worth testing both with ntsc if possible.

finally another (slightly round-about) option could be to take the hdmi output from recurboy and convert this to composite with an hdmi->composite adapter and see if this would solve your problem

i would like to build a mainbow one day (and am also in PAL land) so if i ever do will be able to test this for myself also

1 Like

@looseopinions are you using PAL or NTSC?

@cyberboy666 thanks for the tips! At the moment I don’t have any of the devices you mentioned so I can’t test it but I probably will need a hdmi > composite adapter soon so will purchase one and let you know.

It’s not all that urgent anyway, just looking forward to when I can do most of my visuals without the ol’ laptop!

I’m on NTSC. Also I’m the person that had trouble with Mainbow showing up B&W on my Roland V8, and putting a dist amp inbetween those two to amplify the signal fixed that issue. However, I’m able to go straight from recurBOY into Mainbow with no amplifier. Definitely worth a try though. I’ve found a little amplification between things has helped other issues throughout my analog signal chain.

1 Like

I finally found a moment to test and I can confirm that if I put both the Mainbow and recurBOY into NTSC mode it works as expected. Yay, I guess? Would this suggest that the issue appears to be the PAL signal being generated by the recurBOY?

1 Like