timsabre

Correct termination for audio as well has a 200R resistor + 10uF capacitor in parallel with the 4K7 resistor. You should probably include that to prevent any audio weirdness on your branch line http://www.dmx512.com/web/comms/tecpro/tptech.htm

The perfect height is to put it at the eye height of the person speaking. Anything else will look strange and the further off eye height you are, the stranger it will look. This is why at professionally recorded events you will often see cameras on a platform in the middle of the audience. Obviously you will have a compromise with what is actually physically possible - if you already have the camera, get it into the proposed position and see if you can live with the picture you get. If you don't have the camera, use your phone to get some test shots. If you have an android phone you can use Droidcam-OBS app (free version) to livestream into OBS software (free) from your phone camera as a test.

Might depend on the manufacturer maybe? Normally the call light button puts a DC offset on the audio line. This is ramped up and down fairly slowly to avoid a click on the audio. The DC termination is involved in the time constant of this ramp, without the termination it goes up very quickly (hence the click you heard) and down very slowly, so the call light might stay on for ages.

It doesn't die or anything with 2 terminations. The effect is that the call light doesn't work or only flashes if you hold the button down (normally it would continue for a time after you release the button). And the sidetone settings (how much you hear yourself in your own headset) all become different to what they normally are. With no termination the call light sometimes flashes all the time once the button has been pressed, or flashes by itself, or doesn't work at all. And the sidetone becomes totally unpredictable, lots of headset feedback etc.

This is correct, the double termination would cause problems. The termination has an ac component for the audio and a dc component for the call lights - using a transformer would fix the dc problem but the double audio termination would still be there.

Probably not as most manufacturers use a custom protocol for sound to light mode. But you could try plugging them together and see what happens?

I've not seen one either but I suspect given the statement "80W equivalent" that it is using WS2812 pixel LEDs as the light source, rather than the normal 3W RGB led you get in LED par cans etc (which would be at least 144 "real" Watts). So I think it will not be very bright - think of 80cm of pixel tape...

Perhaps it is time to reveal this secret code in the public domain, if you manage to find out what it is... There can't be many qcommanders out there any more and it sounds like the information is in danger of being lost forever

There's definitely something weird about the order of the connections in that cable. From your pic it looks like the left two pins (which you have labelled Red+Green) are the supply to the opto, the middle one is the decoded+optoisolated DMX data signal, and the right hand two are the isolated supply to the 75176. You've remade that cable, are you sure you have remade it correctly and not mirrored one end?

Thanks all. What they're actually proposing is having bars on the east side of some pillars to make them less visible so rather like pstewart's image. But probably using derig arms to hang fixtures.

Rewinding a bit, when you say it doesn't POST, how are you determining that? Could it be a display output problem or similar?

Hi, I am trying to explain to a group of church people who have never seen lights mounted on a vertical boom what this would look like. My google ability is failing me as I cannot find a photo of lights rigged on a fixed boom (e.g. behind prosc in a theatre or on a FOH wall). There are a couple showing tank traps but I really need a photo of a permanently installed one. Does anyone have such a photo (or is better at Google than me)? Bonus points if it is mounted to a pillar in a church! Needs to show a single pipe not truss.

I've got a Siglent SDS1104X-E but that picture isn't mine, however it looks pretty similar on the screen. £379 in the UK, it is a good bit of kit for the money.

No, having multiple notes together would work, but as you start adding more channels to control, they will not all happen at the same time, as it takes a few milliseconds to send each MIDI command. This is most noticeable with fast flashing, and if you need to do a fade it can look steppy. 12 dimmer channels and 2 LED pars would not be a problem. I still think it wouldn't be very nice to program on cubase in the way you are suggesting though.

DMX through a scope looks like this at pin 1 of the 75176 (the yellow trace). The long "low" at the beginning is the breaktime which is used to detect the start of the packet The differential signal into pins 6+7 looks the same except one of them is upside down. Also the signal may be a lot smaller and have noise / wiggles on it. (picture from https://community.element14.com/technologies/open-source-hardware/b/blog/posts/DMX-explained-dmx512-and-rs-485-protocol-detail-for-lighting-applications which is a good read for DMX background info)

If you have an oscilloscope, trace the DMX through from the sockets to the mainboard. It goes into pins 6+7 as a differential signal and should come out on pin 1 as a normal serial data stream. Most likely, in common with all DMX devices, the 75176 has got blown up.

The conventional way of doing this is to program the scenes/chases on the lighting controller and recall them by midi notes, because (unless you only have a very few lights) if you do what you suggest you are quickly going to end up with a whole load of notes all on top of each other - for one thing MIDI can only send one note at a time so there'll be a perceptible delay, and also it will be horrible to edit on cubase. For your LED par cans you have 3 or 4 parameters per light so you'd have to send a note for Red, par can 1, another for Green, par can 1.... This is how the MIDI to DMX converters work and it was OK when you had 12 channels of dimmers, but now if you have 12 LED pars you're controlling 48 channels of DMX and it isn't practical - I expect this is why MIDI-DMX converters have fallen out of favour. Also performing fades between scenes is pretty much impossible by direct MIDI commands due to the amount of notes you have to send. Personally I'd be looking at DMX controller software to do this since you don't need a live control surface to operate the show and that is the expensive bit. You could probably run the show with the DMX controller software on the same laptop as cubase, though for programming having 2 separate computers would probably be easier.

What lights have you got... and what aspect of the lighting are you wanting to control with your midi controller messages, over and above the note on-off for scenes? The big advantage that control software (and more expensive desks) have over the base level lighting controllers is ease of fixture control and programming using personalities. On the basic controllers you just have a bank of sliders to control each DMX channel of the lights, which is not so bad if you've just got RGB par cans but gets confusing quickly for anything more complicated than that. Most control software, and better desks, will let you set what type of fixture it is, then use a colour picker to set colour and separate controls to set position, gobo etc.

If the fixture is designed with DMX/electronics ground connected to mains earth/chassis then you should not change this. Some power supply modules have floating DC outputs which can result in quite a high voltage on the power supply DC ground relative to earth. This can blow up DMX interfaces if connected with the power turned on (and give you tingly feelings if you touch the DMX). So to get round this they link psu DC ground to mains earth (sometimes via a resistor, fuse or fusible resistor). Removing this link is unwise.

Um. I don't want to sound like an old fart but repairing high power mains electronics like this is a dangerous thing to try with limited experience and an internet forum. The chances of damaging yourself is quite high. If you feel you really must do this, you will need a variac (variable transformer) which allows you to ramp up the mains voltage from zero, this lets you track down problems before everything blows up. Also I'm not sure how your mains is wired but in the UK where our mains is earth-referenced we use an isolating transformer on the test board which reduces the risk of electric shock.

It's double sided rubbery tape on the ones I have seen. Often backed up by a bead of silicone. Something like this https://cpc.farnell.com/pro-power/adsft50x10/tape-double-sided-foam-50mm-x/dp/CB20013

They looked like this... Just a u shaped casting with a bolt closing the open side if I remember correctly (usually a lot less shiny than that...)

If you have some cast onstage for this sequence, I would do it as an acting gag with all of the cast looking towards the "bounce" points on the sound effects cues. Pan the sound effects to alternate sides. Think tennis audience following a ball type of thing. Use dafter sound effects as it goes on like cows mooing etc. Then you could use the normal sprung arrow trick for it to appear in the target at the end. I think that would get a better laugh than a possibly cheesy looking arrow on a string or other attempts to physically reproduce it.

Wow that's a blast from the past. According to google: Master disco has an option for you to regain control of your console even when someone changed your password for the coef masterdisco the password is 16-10-6-8

If no DMX but everything else works then 75176 would be your first bet. It is unusual for a micro to fail. Sometimes you can zap individual pins if something else fails and puts a big voltage into them. If one colour missing this is often an LED failure as the LEDs are wired in series strings. You can find a faulty one by bridging them out one at a time. Also the mosfets sometimes fail but they often fail shorted on which can kill the LEDs by overcurrent. Also the sense resistors (the big ones near the mosfets) sometimes go open circuit due to thermal stress but this is easy to detect with a meter.