Using LED kit for stage lighting in a school

[Cobalt]

Hi,

 

I'm wondering if anyone has got any thoughts on using LED kit as stage lighting in a school environment. I've been stalking the forums for a while now and read countless articles about stage lighting, so whilst I'm learning it'd be good to hear from some people in the know with experience. I'll put some background in to make things clearer.

 

I am a technician (IT rather than AV, though the two - and many other roles - are used interchangebly) in a secondary school and we are considering putting forward a proposal to replace the school hall lighting system. Currently, we have a lovely system which was installed by Custom Theatre Services many years before I came here. It comprises of a 24-way Horizon dimmer rack coupled to a same-brand lighting desk. On these we have a variety of lanterns including a couple of Teatro profiles, a handful of fresnels (various old bits of Strand kit I believe), a few floods and so on. Nothing special, but it does a job and most of the fittings are probably perfectly fine if in need of some TLC.

 

Whilst the dimmer and desk have the magic word DMX written on them, neither seem to use the actual standard. In fact, once we created a 5-pin XLR to 5-pin DIN cable and plugged in a true DMX-compatible board and we were left with most full on and partial control over one of the channels - not overly helpful! I've come to the conclusion after much searching that the timing is wrong

 

We had a quote in to replace our dimmer rack with a Chilli model and upgrade the wiring. Whilst the quote was probably about right, it was more than we could really afford to spend and as such no more was done. However, another year on I've been looking into options and came across LED fixtures. As these do not require the dimmer rack, it seems to work out considerably cheaper. We had a local company come in to show us some LED kit and it seemed fairly impressive - They also said they could use the power into the existing dimmer unit with a bit of rewiring so again keeping the costs down.

 

My question is, is LED kit suitable for this sort of use? As a school we have a mix of plays by the Drama department at Christmas/Summer and various music and dance events - Think "Got Talent". It doesn't get a massive amount of use, perhaps two or three shows a year and two or three kareoke/talent competitions which we like to light as well, so hire is potentially an option, though I think we'd rather have something we can use at any time. Additionally, if we had a good, reliable rig, perhaps it'd encourage more use...

 

My real concern is that the Horizons desk we've got is in a poor state of repair, and if anything happens to it, we have no means of controlling the lights and I doubt we'd be able to acquire one of these seemingly bespoke desks at short notice should we need one.

 

Let me know what you guys think and any questions, please ask.

 

Thanks,

John

[themadhippy]

once we created a 5-pin XLR to 5-pin DIN cable and plugged in a true DMX-compatible board and we were left with most full on and partial control over one of the channels -

Silly question but did you try another desk,cable,check the patch,hit with hammer ect.

they could use the power into the existing dimmer unit with a bit of rewiring so again keeping the costs down

Led stuff is a fairly low current draw,and only needs hard power,so a convenient 13A socket will do.

 

finally if you've dimmers left more par cans

[Brian]

I've converted several Horizon systems to 'standard' DMX desks now and they've all worked OK Timing isn't usually an issue. IIRC the master clock in the racks is a crystal oscillator so that should still be OK. DMX break detection might be with an RC timing circuit, I can't remember and my files are 400 miles away.

 

From what you've described it sounds like pins 2 and 3 are swapped.

[Cobalt]

Themadhippy - Well we've tried two cables (though admittedly self-soldered) and another desk. We didn't hit anything with a hammer, though I'm more than willing to give it a go...

 

Brian - That may be encouraging, I will make up a cable and try reversing the data pins from before and see what happens. I'd have thought we'd have tried it at the time - there were plenty of attempts! - but quite possibly not so I'll give that a go.

 

From an equipment point of view the dimmers do a decent enough job and the fixtures will be fine with a bit of maintenance work so I'd much rather be able to use a new desk and maybe buy a few more lanterns to improve the setup rather than replace the lot (I think the bursar would be with me on that score as well) so I'll give it a bash.

 

Thanks for the suggestions.

 

John

[j_b]

You did get the pin numbering right in both the DIN and XLR - they are different sequences....

 

http://www.blue-room.org.uk/index.php?showtopic=18581