Hi! The school where we perform has a Horizon rack as described. Unfortunately during lockdown the dimmers either drifted or were tweaked so the pre-heat was too high, and it was impossible to get a blackout (you got a red glow instead). I asked the school to have this corrected when their tame PAT tester came in, but unfortunately he's now set it totally wrong, and some dimmers don't come on until 50 or 60%. Although I've built my own dimmers in the past, and am fairly familiar with what's going on, not surprisingly I'm not allowed inside the box. However, I'd like to know as much as possible before trying to get the man back to fix it (hopefully while I'm there!). So: (a) if acooper is still around and sees this, would it be possible for you to post or put in, say, dropbox, a higher resolution image of the internals? (b) does anyone have any technical information on the Horizon, or know where I might find it (Googling only yielded this page); and (c) failing that, does anyone know what the trimming entails (I'm kind of assuming there's either one pot or two which control a base level and possibly tweak the top end so you can get maximum brightness).
