ShowMagic & Analogue Dimmers

[mikeburnie]

I'm just getting into lighting so my knowledge is very very poor on the subject at the moment.

 

In our theatre we have a ZERO88 Sirius 24 lighting desk and what looks like one Zero88 dimmer and a few Furse EDM 6103 dimmers. They are all as far as I am aware very old analogue dimmers and I believe they run from 0 to 10v signals.

 

I would like to make lighting simpler for newer users and have been investigating the ShowMagic product. It looks like it would do everything we need for our small amateur theatre.

 

The problem I have is that the ShowMagic product appears to work with DMX only. We only have the anaolgue stuff and we cannot afford to replace our equipment.

 

Our Zero88 Desk seems to plug into our dimmers via a 25 pin connector (looks like a computer serial connectior)

 

Are there any small cheap boxes that would plug into a laptop to convert the DMX from ShowMagic to normal Analogue signal ?

[Cuelist]

Are there any small cheap boxes that would plug into a laptop to convert the DMX from ShowMagic to normal Analogue signal ?

 

Yes, you need a 'demultiplexer' or 'demux' for short. This is a device that recieves DMX512 and turns it into a number of analog outputs. There are many to choose from, one that would work directly would the "QDeMUX" from Lightprocessor. It has the 8-pin DIN connectors that matches the ones on the Zero 88 dimmer connections.

 

The brand/make of the demux does not need to match that of the controller or dimmer(s) as demux are general purpose devices.

 

You might be able to pick one up second hand as well, try some local lighting rental companies.

 

 

Mats Karlsson

[dirkenstein]

Indeed, what Mats says is exactly right. You need a demux.

The cheapest demux generally available right now is whatever the current guise of the Botex ME-72 is. This tends to be sold by companies like Thomann for about £110 (£115 from stagelighting.co.uk). It is significantly cheaper than the equivalent equipment from Zero 88/Strand and so forth. It supports up to 72 channels of analogue 0-10V dimming.

 

We have two and are very happy with them. Now we'd just like to acquire another 100-odd channels of dimming and we'd be able to use them to their full potential...

 

However, it has two major disadvantages:

 

a) The unit can be switched to perform both 0 to 10V and 0 to -10V dimming, but only for the whole unit at once. This means that if you want to run a mixture of Zero 88 (betapacks autoswitch between 0 to 10V and 0 to -10V analogue) pulsar (0 to 10V positive only) and strand dimmers (0 to -10V only) you need separate units for positive and negative analogue dimmer signals. By your description, this problem wouldn't apply to you as you've not mentioned owning any strand kit. I would be deeply surprised if something made by Furse could auto-anything (except possibly auto-destruct) so I suspect they'll be 0-10V positive only.

 

b) The ME-72 demux does not come with pre-made cables, and the 25-pin outputs on the back have a totally counterintuitive (if perversely logical, from an engineering perspective) pin-out that is completely different to the one used by the 25-pin connectors on your Sirius desk. You need to either be competent with a soldering iron and low-voltage electronics (or find somebody who is) to make up appropriate 25-pin to 8-pin or 25-25pin adaptors. I would generally recommend siting your demux as close to the dimmer rack as is possible to keep the runs of analogue cable short. Which means you will need to run DMX cable from your control booth to your dimmer rack. I don't know of a commercial source of the appropriate adaptor cables pre-made. I have this memory Strand may make some for what I believe to be their rebadged model of the ME-72 but I heard the price was in the realms of the ludicrous ( over £100 for the cable).

 

However, before you follow my recommendation, have a look at this thread where various forum members describe their trials and tribulations with this equipment, before you take my word for it.

 

Previous Thread on the ME-72

Another more detailed thread on the same topic

 

Also, be aware that unless your Sirius is also equipped with a DMX output you'll want to leave whatever analogue cable you have in place, so that you can continue to use this as a back-up should you need to (specifically, should your funky new show control PC go the way of all PCs and crash at a deeply inopportune moment. You would only be a quick cable re-patch away from at least throwing some light on stage).

 

 

Dirk

[tokm]

Yes, must agree, the downside to all these high output number demux's is that the spiders are hard to get hold of or make..

 

Does anyone on BR know of a place where these cables are available from.. other than strand/genlyte?

 

Tom

[Don Allen]

I suspect that the Botex ME-72 is made in the same factory as the Showtec Multi Exchanger and maybe the Strand demux ?

 

The difference is the sex of the db25 connectors. The Strand and Theatrelight (NZ) demux and others ? have male db25 connectors which is probably not a good idea as the pins can be shorted out, but the output circuit should be able to handle it.

 

The Showtec Multi Exchanger has female DB25 connectors and I presume the Botex ME-25 so the pin numbering is REVERSED, which is why confusion reigns when people try to work out connecting cables.

 

On a male DB25, looking at the pin from the front of the connector, top row has pin 1 on left and pin 13 on far right.

On a female DB25, looking at the sockets from the front of the connector, top row has pin 13 on left and pin 1 on far right.

 

You can use a male db25 to male db25 gender changer (thanks to David for that one) and they have screws to lock them into place or if you are very good with a soldering iron, swap the sex of the db25 connectors. No need to make up a breakout box.

[musht]

Yes, must agree, the downside to all these high output number demux's is that the spiders are hard to get hold of or make..

 

Does anyone on BR know of a place where these cables are available from.. other than strand/genlyte?

 

Tom

 

As suggested easiest breakout is getting an all pins wired parallel printer cable, some of the thinner ones aren`t all pins wired, and chop one end off.

 

Strip back and tin all the ends, hold the cable to the bench with a generous blob of blu-tak and fan out the ends, apply the iron and solder to each bared end in turn leaving all the ends generously coated in solder. set aside.

 

Clamp connector in small vice or embedd in blutak facing up, sparingly tin all the connector pins, not too much that you fill in the solder buckets but enough to coat the pins so they are shiny silver.

 

Hang cable over connector, tend to use spare anglepoise for this myself, so that tinned ends are hanging down over connector.

 

One at a time hold tinned wire into tinned connector pin and apply iron. The solder will reflow between wire and connector pin and make a joint. Make several joints and then examine for signs of dry jointing, dull rather than shiny silver joint. If any joints look like this apply iron and solder briefly to touch up joint with fresh flux.

 

Because you`ve made several connections the wire will be held whilst you retouch the joint, if it still goes dry after re touching , uses solder sucker and remake joint. Again because your cable is hung over connector and several joints are in place you can do all this without needing to grow extra arms.

[Tomo]

The advice given so far is spot on, and would be a good investment on general grounds - you'll be able to use a DMX > analogue demux with almost every lighting desk currently in production.

 

One thing that I do find strange is that you think that moving to ShowMagic from a Sirius 24 will make things simpler.

 

Obviously the right desk for you depends on a great number of things, but in your situation I wouldn't even consider moving from a fader-per-channel desk like the Sirius 24 to a PC-based desk.

 

You already have one of the easiest desks for an inexperienced operator to use - you push a fader, a light comes on.

Recording shows on that desk is also fairly easy - it was the first memory desk that I used, and it was extremely easy to pick up.

I do remember that editing memories was rather fiddly, but that's not exactly a major problem for an inexperienced user as the only problem was that you had to re-make the memory completely - this takes time, but it's an easy concept to wrap your head around.

 

PC-based systems (like ShowMagic) don't have this tactile user interface - everything has to be done through a computer keyboard and mouse.

 

Would you care to explain why you think this is the best move for your venue?

 

It may help you to decide the best course of action if you take the time to discuss it with some outsiders.

[mikeburnie]

We are a small amateur theatre (only 142 seats). We have some people who may be able to sit in a very small lighting box but who have no comprehension of the concept of lighting and be able to run a show. The showmagic product seems to be able to allow you to SCRIPT a show and integrate sound cues into the script as well. We have major problems getting anyone to help backstage (like a lot of other theatres) and some people find the lighting desk very daunting not to mention the concept of lighting. It would be easier to find ONE person to run the lighting and sound by pressing a space bar rather than finding two people to commit for two weeks, one for sound one for lights. Its a sad fact that getting people to commit to a production seems to be very difficult for a lot of theatres at the moment. My thoughts were if a show could be scripted on a laptop (which we already have) it would at least help us over this lean period until such time as we have more interested people in lighting. We have a couple of people who can rigg lights but cant commit to lighting productions

[dirkenstein]

The Showtec Multi Exchanger has female DB25 connectors and I presume the Botex ME-25 so the pin numbering is REVERSED, which is why confusion reigns when people try to work out connecting cables.

I think you're right. The male and female connectors are mirror images of each other and people always go and solder things for pin 1 to pin 13 and vice-versa.

 

However that isn't the only problem.

 

PCB mount right-angled DB connectors can break out all individual pins onto one 'plane' on the PCB. Notice the pins and in the top and bottom row are offset by half the spacing between adjacent pins, so you could imagine 'flattening' the whole connector into one tightly packed row. If you put all the tracks to the connector pins on one side of the PCB, tracks from alternate pins from the top and bottom row wind up in order.

This means, looking at the PCB, you pins will break out into a 'bus' of tracks with the following numbering for a female PCB mount conector, viewed from the front and counting from the left.

 

pin 13, pin 25, pin 12, pin 24, pin 11, pin 23 ..... pin 15, pin 2, pin 14, pin 1

 

You can use a male db25 to male db25 gender changer (thanks to David for that one) and they have screws to lock them into place or if you are very good with a soldering iron, swap the sex of the db25 connectors. No need to make up a breakout box.

Yes this would probably work with a Strand demux adapter cable (with a female D-connector on it), but it would't work with a Zero 88 25-pin desk to 8-pin demux cable, for the following reasons:

 

Lots of gender changers are designed to preserve the correct pin ordering, so that pin 1 does not wind up being pin

13 and vice-versa.

 

Zero 88 use the 'standard' pin-out for channel ordering on the Sirius:

 

pins 1-24 are channels (pin 1 = channel 1, etc) and pin 25 is common. The pin numbers here are the 'official' numbers found on labels next to the pins, as Don described in his post.

 

Botex actually uses the 'flattened' ordering I described above.

 

Checking aginst the diagram in the ME-72 manual:

 

Channel 1 - pin 13

Channel 2 - pin 25

Channel 3 - pin 12

Channel 4 - pin 24

...

Channel 22 - pin 15

Channel 23 - pin 2

Channel 24 - pin 14

 

Common/0v - pin 1

 

A gender changer won't fix that for you!

 

Unless you can find a source for this particular cable type you'll need to build a 25-pin breakout box or make your own cable.

[pritch]

We are a small amateur theatre (only 142 seats). We have some people who may be able to sit in a very small lighting box but who have no comprehension of the concept of lighting and be able to run a show. [snip]

I see your point Mike, and agree to an extent.

 

Running off a PC is all very well and good, until something goes wrong. And I'm not just talking about the PC going wrong, either, in fact I'd say that it's the least of your worries.

 

What if a fuse / trip goes and takes out a dimmer channel? What if a lamp blows? What if the talent unexpectedly moves to an unlit area of the stage (something which amateurs are very good at, in my experience)?

 

These things are easy to busk with a desk, especially one where there's one fader per dimmer such as the Sirius. I'm not sure I could come out with a hasty fill-in on a computer based system quite so easily.

[edark]

I use show magic at my theatre and I think its great. It is very easy to use yet powerfull enough to do almost anything when you really get to know it.

 

I have PCI DMX card in my PC which gives me an DMX out and a DMX IN to the PC. Show magic can merge the DMX line in with its own DMX. This means I can have a fully functional Zero 88 Serius 48 for hands on control, flashy buttons, faders etc. but the power of the pc for the Cue stack. You can even use the flash buttons as a GO button for you rcue stack on showmagic, it really is very powerful.

 

I may have a zero88 DMX to analouge convertor coming up for sale soon. I shall prob pop it on ebay, but I'll certainly let you know when I do.

 

Pritch: I understand your concers about running a PC based system, but I can honestly say in the 2 years that I have been using show magic, it has crashed twice, and that was due to me trying to run dual video files with the wrong codecs (user error!) and not enough ram. Plus the application starts up in about just 2 or 3 seconds.

My Zero88 sirius 48 crashes more often!

I may be wrong but I think many lighting desks these days, including the hog2 run on XP operating system.

[johnhuson]

I may be wrong but I think many lighting desks these days, including the hog2 run on XP operating system.

 

You are right, however hardware based controllers use Embedded XP and not your standard XP you find on your average PC. I don't want to go into too much detail about the difference between the two as it's been covered here before and would be quite off topic. But to sum up briefly Embedded XP enables software developers to use the parts of the OS they require and nothing else that can clog up processor etc. Briefly on that note, anyone that is considering a PC based controller and the PC is to be used purely for this function (as it should be!). Then I would recommend XPLite Software, it enables you to remove all the components that you don't need like help, screen savers etc. that you don't need, which is bound to increase the speed/stability of a system.

[dbuckley]

The points raised about the suitability of consoles over PCs are only really relevant if your experience is in running shows using a console.

 

If you start from scratch, with no lighting experience, and you are a competent PC user, then a PC system is a fine tool. Its not perfect, lack of faders and bumps is a problem for some genres, but for scripted shows, a console is altogether a less appropriate tool than a PC. Consoles continue to get used, however, 'cos thats what lighting people use and earn their money knowing how to use.

 

Using your exisiting desk as an input device for a computer can give you the best of both worlds, as edark mentions above.

 

The other thing I would mention is that there are a number of decent PC based controllers that are affordable, and a shedload which are crap. Show magic is good, but fairly expensive. I'd suggest you also have a look at the rest of the usual suspects, There's a list in the lighting FAQ