Portable 2- or 3- channel dimmers

[gibbothegreat]

Hi Folks, I'm looking to expand the number of dimmers in my theatre, and one possible solution would be to run the FOH perch positions off local dimmers powered by 13A: currently, they are fed by patch leads from the stage dips, but as we don't have that many of these, it would be good to find a different solution. Typically, we only use 2 circuits at these positions. There are both mains and DMX outlets available locally.

 

An Alphapack a side would be ideal except for the limit on its DMX start address, I need them to be somewhere in the 100s. Does anyone know of a similar dimmer, ideally with 15A outlets? Alternatively, is there a way of 'renumbering' DMX information, so that where the desk is talking to chs 101 - 106 the Alphapacks think they're being addressed on chs 1 - 6? Final and least favoured option might be to convert to analogue and run Alphapacks off that, can anyone see any pluses or minuses in going that route?

 

 

[indyld]

There might be options, but you don't mention the rest of the system numbering or the desk you are using. One option could simply be to run another universe. Or renumber the current dimmers to allow for the restrictions of Alphas.

 

I'm pretty sure I've used 3 or 4 channel portable dimmers that don't have the numbering limits, but can't remember what they were.

[gordontech]

I have a box full of multidim 2's. Their IEC portable dimmers with paired outs, 3 pin DMX and a choice of channels on them. Cheap and easy to use, they are always my get out of jail free card for small things. Made by showtec and they are reliable as an alphapack. Make up some IEC-15a jumpers and you should be away.

[gibbothegreat]

There might be options, but you don't mention the rest of the system numbering or the desk you are using.

 

Ah, apologies, it's a Leapfrog 96 with 96 dimmers plus houselights. The desk has (IIRC) two universes with an option for two more.

 

 

 

 

One option could simply be to run another universe. Or renumber the current dimmers to allow for the restrictions of Alphas.

 

I've no experience of running separate universes, is it easy to address more than one simultaneously?

 

Renumbering existing dimmers had occurred to me, but it would be a bit of a bore changing all the labelling...

 

 

[Brian]

I've no experience of running separate universes, is it easy to address more than one simultaneously?

You sort it in the patch on the desk.

[CallumP93]

We use dimmers very similar to this without issue, cost £80 ex VAT from CPC at the moment (cpc.farnell.com/transcension/bote27/DMX-dimmer-pack-4-channel/dp/DP2908317?Ntt=DP2908317)

Including the making of adaptors you are looking under £100 ex VAT each. Full 512 addressing, and you can set it up as either a 1,2 or 4 channel system.

 

Or when they are back in stock http://www.stagelighting.co.uk/control/dimming/budget/4-channel-iec-dimmer-5-pin-DMX, as these use 5 pin instead of 3 and work in the same way.

 

Callum

[jonhole]

I've no experience of running separate universes, is it easy to address more than one simultaneously?

This is really easy on the Leap Frog 48 & 96 - if you want to go down this route we can easily talk you through it over the phone if you would like

[indyld]

I have a box full of multidim 2's. Their IEC portable dimmers with paired outs, 3 pin DMX and a choice of channels on them. Cheap and easy to use, they are always my get out of jail free card for small things. Made by showtec and they are reliable as an alphapack. Make up some IEC-15a jumpers and you should be away.

 

That's the ones!!! IEC jumpers, plus 3 - 5 pin XLR sets, they are a bit of mess with all those odds n ends hanging out of them. But I'm sure they were more flexible on the DMX address front.

 

With a second universe on the Leap Frog, the issue is likely to be how to get that universe to all new dimmers. If DMX is available nearby, then I'd assume that this installed feed is sent from a DMX splitter. Depending on the layout, it might be easy or hard to send Universe 2 to additional dimmers, harder if only one splitter is available - and needed for Uni 1. Also, if the nearby DMX outlets are already being used for Uni 1 duties. But there will be a way.

 

Alternatively, is there a reason why your 96 dimmers need to start from 001? (This is ignoring the fact that you already have 96 dimmers plus H/L so not entirely clear where you will find the additional desk channels for the new stuff without pairing up dimmers to handles, presumably different each time depending on the show)

[Stuart91]

I have a box full of multidim 2's. Their IEC portable dimmers with paired outs, 3 pin DMX and a choice of channels on them. Cheap and easy to use, they are always my get out of jail free card for small things. Made by showtec and they are reliable as an alphapack.

 

That certainly hasn't been my experience.

 

We owned some much abused Alpha packs for many years. They were much abused, dry hired to all and sundry, and I'm sure were overloaded on occasions. Over a period of roughly five years, we only had two failures. One pack failed when someone stood on it, and shorted the casing onto the main PCB. Can't complain about that really. Another time somebody supplied a 15amp plug with a loose connection, and the heat welded the plug into the socket. A replacement socket was supplied by Zero 88, so no problem there.

 

On the other hand, every Multidim I have come across has broken. We bought a few, and they blew triacs the first time a bulb failed. A batch of dimmer bars with the same electronics were nothing but hassle. I have had at least a dozen broken Multidims (or similar units rebadged by other importers) brought in for repair by hapless customers.

 

In addition to the triac problems, the physical build quality is poor. It's very easy for the buttons to break, the IEC sockets are not the greatest, and the whole thing feels quite cheap.

 

Admittedly, I'm coming at this from the angle of a reasonably busy hire company, with many customers who are novices and probably put above average wear and tear on equipment. Maybe if you keep a Multidim to run birdies and treat it with kid gloves it will behave all right. But I'd far rather you bought something else rather than allowing such a poor, cheap-ass design to continue in the marketplace.

 

 

Alpha packs are great, but a little out of reach of many budgets, and the limitations in DMX addressing can be annoying.

 

A good compromise is the Lite-Puter 4 channel packs - the DX401and 402. They are available with IEC connectors on them, and have dual mains inputs so you can, for instance, run 4kW of lamps without overloading your supply. I now own a bunch of these and have installed several dozen. Only one problem, which I think was down to gross overloading by a clueless user, and we were able to get a new board which was a straight swap out.

[gibbothegreat]

This is really easy on the Leap Frog 48 & 96 - if you want to go down this route we can easily talk you through it over the phone if you would like

 

Thanks Jon - if I acquire Alphapacks I'll certainly take you up on it. Much appreciated.

 

 

With a second universe on the Leap Frog, the issue is likely to be how to get that universe to all new dimmers. If DMX is available nearby, then I'd assume that this installed feed is sent from a DMX splitter. Depending on the layout, it might be easy or hard to send Universe 2 to additional dimmers, harder if only one splitter is available - and needed for Uni 1. Also, if the nearby DMX outlets are already being used for Uni 1 duties. But there will be a way.

 

Alternatively, is there a reason why your 96 dimmers need to start from 001? (This is ignoring the fact that you already have 96 dimmers plus H/L so not entirely clear where you will find the additional desk channels for the new stuff without pairing up dimmers to handles, presumably different each time depending on the show)

I do have 2 separate splitters specifically so I could offer the option of distinct universes to visiting shows who are touring their own inteliigent fixtures, so no problem there.

 

Renumbering the existing dimmers is certainly possible, just would require something of an investment in time to manage it, and we don't get any dark period in our year, so when we do get gaps of a few days, lantern and cable maintenance is the first priority.

 

 

 

.

 

Admittedly, I'm coming at this from the angle of a reasonably busy hire company, with many customers who are novices and probably put above average wear and tear on equipment. Maybe if you keep a Multidim to run birdies and treat it with kid gloves it will behave all right. But I'd far rather you bought something else rather than allowing such a poor, cheap-ass design to continue in the marketplace.

 

 

Alpha packs are great, but a little out of reach of many budgets, and the limitations in DMX addressing can be annoying.

 

A good compromise is the Lite-Puter 4 channel packs - the DX401and 402. They are available with IEC connectors on them, and have dual mains inputs so you can, for instance, run 4kW of lamps without overloading your supply. I now own a bunch of these and have installed several dozen. Only one problem, which I think was down to gross overloading by a clueless user, and we were able to get a new board which was a straight swap out.

 

They would be effectively permanently installed, so hopefully wouldn't suffer too much mechanically. And they would only run (typically) 2 x 650w lanterns each, so again electrical stress shouldn't be sever either, although I'm dismayed by what you say re bulbs blowing taking out triacs

 

 

 

 

 

However, those Lite-Puters look ideal, I'll certainly investigate sources for those, although any recommendations gratefully received.

 

 

 

 

Many thanks for all the input, I was sure someone here would come up with a viable solution, and you didn't let me down!

 

 

[gibbothegreat]

A good compromise is the Lite-Puter 4 channel packs - the DX401and 402. They are available with IEC connectors on them, and have dual mains inputs so you can, for instance, run 4kW of lamps without overloading your supply. I now own a bunch of these and have installed several dozen. Only one problem, which I think was down to gross overloading by a clueless user, and we were able to get a new board which was a straight swap out.

Hi Stuart,

 

Do you have a recommendation for a UK source for these? I could only find one online, and they didn't list the DX402, which would be my preferred option...

 

 

 

 

 

Many thanks,

 

 

 

 

 

[Nicktaylor]

I have scanned this list of posts. the one thing no one appears to have mentioned is mixing phases. While I appreciate people dont seem so concerned now days, it is quite likely the 13A supply will be one phase and the stage kit another, so a risk of 415v between phases. Just a case of labelling I think unless there are local rules?

[gibbothegreat]

I have scanned this list of posts. the one thing no one appears to have mentioned is mixing phases. While I appreciate people dont seem so concerned now days, it is quite likely the 13A supply will be one phase and the stage kit another, so a risk of 415v between phases. Just a case of labelling I think unless there are local rules?

 

Fair point, Nick, but the 13A is infact off the same phase as the existing patches, so even if we end up using both (unlikely as there simply isn't space for more than three lanterns) then there wouldn't be a problem, and they're not within anyone except a contortionist monkey's arm's reach of the nearest other fixtures. Good to be reminded of that, though my understanding is that it isn't a strict requirement anymore, still good practise. Additonally, all our mains and dimming outlets are RCD protected, am I right in thinking that would protect against a cross-phase problem?

[themadhippy]

though my understanding is that it isn't a strict requirement anymore, still good practis

the need for labeling were stuff was on seprate phases but wiothin reach of each other was last seen in the 15th edition

Additonally, all our mains and dimming outlets are RCD protected, am I right in thinking that would protect against a cross-phase problem?

nope it will sit there all day letting the fault current pass until either it melts or a fault to earth occurs

[indyld]

Additonally, all our mains and dimming outlets are RCD protected, am I right in thinking that would protect against a cross-phase problem?

nope it will sit there all day letting the fault current pass until either it melts or a fault to earth occurs

 

I think that the "connection" between individual RCD protection and phase to phase potential faults is cited by some, only being that "people protection" is readily available at 30mA on individual circuits. This doesn't make a 415V shock any safer, but is held up as the reason by many show sparks and why they are a lot less concerned about such phasing considerations, including different phases on a bar and even the sending down a single multicore for some it seems.

 

I'm not saying it's right, just reflecting on current practice in the business. Strangely enough, doing power distro for a temporary kitchen the sparks will usually plan coherent phasing at the various cooking stations, whereas will be more, er, flexible when it comes to, say, a lighting truss.