Kulp K32A-B Differential Receiver Flickering

[jrlapeters]

Hi everyone, describing an issue that flummoxed me the entire 2025 season.  I expanded the use of differential receivers this year (ran 2 with no issues during 2024) and most ports from the 4 receivers had random flickering during both musical sequences and using FPP port test mode.  There was no flickering coming from the main controller outputs, only those on the receivers.  It appeared a bit random and the flickering seemed to sync among the receivers even though props were in different places.

Here's my setup:
- Kulp K32A-B with BBB, running latest FPP (v9)
- 4 Falcon receivers, 2 V4 and 2 V5

What I tried:
- Upgraded all 4 network cables
- Removed V4's to run only V5's and vice versa
- Switched between daisy-chained to independent from each of the 4 expansion ports on the Kulp
- Replaced (yes completely) the Kulp K32 and BBB
- Reduced frame rate of all sequences to 25fps (helped but didn't eliminate)
- Confirmed proper grounding for all power, swapped power supplies for Kulp
- When flickering was really bad, a power cycle of the Kulp would stop it briefly, and then it would start to come back during the first sequence played

In the end, I'm putting together my original Kulp into a separate box and will just use both Kulps for the whole show, but it's a shame I can't make the diff receivers work.

Has anyone else seen this, or have any suggestions?  I may have missed a few steps I followed since I was troubleshooting from early October at show start through end of December, and it's been a few months since I've thought about this.  But now I'm getting everything out to prep for this year and figured I'd ask the community.  Thanks all!  - Jeff

[jnealand]

I do not have an answer for you, but although I own a couple of receivers I never use them unless I need another port or two with a particular controller and  usually right near the controller.  My observation is that I see way, way too many posts of folks having problems with recievers or even finding information out on which receiver to use and how to configure for using them.  I prefer to use smaller controllers as an FPP remote.  That gives me more flexibility to move things around in my yard and I have no data cables in my yard.  It also minimizes the amount of things that quit working if a controller fails or just starts acting up.  YMMV

[Yffej]

FWIW..
I use FPP remotes and I have no data cables in my yard, but I also use differential receivers for the puck lights on my house and can drive anything on the home.

I also use them to drive for anything near the street. I want to keep the controllers away from the street out in front of my house.

I drive them from an fpp remote via Experience Lights controllers with an ethernet data cable underneath hedges along the edge of my property. This allows me not to run a cable across the yard. I am using Experience Lights RX as well.. They are Mattos Dragon RX, but I see they are not selling them anymore.

I haven't had any issues. They seem to work well for me.  But I have never used Falcon RX.