Control/Dimming - DMX to CD-80 control?

[shiben]

At our college, we began renovating our main concert hall. It is getting a full new dimming system by ETC. However, we now have a 120 channel CD-80 rack sitting around. We have a gym that has 10 or more events per year in it, and we would like to include a theatrical system in the facility. Currently, we only have 2 follow spots that can be used in the space. There are 2 200A company switches located at one end of the facility, right next to a closet that would be used to house the dimmers (the power from the switches would be re-routed, or we would install a new main power feed, depending on budget). We would like to use part of our old CD-80 rack to put dimming into the gym. I would figure a FoH pipe with 12 channels, and 2 over stage pipes with 12 channels each, so around 36 channels. Nothing very fancy, but something functional for lectures, conferences, etc. Can you convert a CD-80 rack to DMX for not a lot of money? We know of a full overhaul which would run around 30k, we were hoping for much less than that. Thanks for your help.

[Footer]

What CD-80 rack is it? It will say on the control module.

The Johnson Systems upgrade is a great way to go. I think it runs about 10k, though I could be way off on that.

Heres another option, legality permitting. Sell all the dimmers on ebay or "insert gear reseller here". People are always looking for CD80 modules. Buy some ETC smartbars or even CD80 packs. It costs a good amount of money to install an entire rack just for 30 circuits. IGBT dimmers are pretty solid and great if you just need a handful of circuits in a given area.

[shiben]

We considered selling them, but the theater company needed them, and so we arranged a gear transfer, which left us with 36 of the units left, and the rack and other associated hardware. How much are we looking at to install the entire rig? Money is pretty tight right now, and so really any expense is frowned upon (its extended to new lamps and gel, which is becoming obnoxious). If we can use something that we have, then that is what is going to get used. Keep in mind that the instal would be done by college staff (we have 3 full time Master Electricians (not for the theater, they are sparks)), and any cable would probably come out of the large inventory of cable we already have.

[coldnorth57]

I am sorry but are not all CD-80 systems DMX compatable????
http://www.strandlighting.com/client...ads/CD80SV.pdf

[Footer]

Originally Posted by coldnorth57

I am sorry but are not all CD-80 systems DMX compatable????
http://www.strandlighting.com/client...ads/CD80SV.pdf

The AMX racks are not without swapping out hardware. Most of the AMX racks controller cards and fans have long since perished.

The real money will come from installing all of the conduit and pulling the copper. A lot of copper has to be pulled, each run needs its own neutral. I would get a person familiur with the CD-80 racks in there to help you guys get it going. If you have a liscened electrcian doing all the hot work that is great, go for it. But, wiring a dimmer rack is a completly different beast then wiring a house/building. Also, what do you intend on doing for raceways? Even if you just terminated in SSRC boxes, its not going to be cheap. I don't think you will be able to get it in and working for under 10k.

[derekleffew]

Contact CB member DimmerDotCom at dimmer.com Home Page. He does this for a living.

Other sources for repair/upgrades are listed in the Collaborative Article Service and Repair. DMX to AMX converters are also available, quite possibly used. See DIY DMX: Demux, Protocol Converters, etc. and Sources for Used Equipment.

[FatherMurphy]

Originally Posted by coldnorth57

I am sorry but are not all CD-80 systems DMX compatable????

The original 1980's CD-80 racks predated the development of DMX, and instead used AMX for control (a pulsed analog voltage signal). After DMX came about, retrofit kits were made available to rebrain the racks and convert them to the new standard. Other things were usually upgraded as well, such as fan speed control and architectural wall panel controls. Other than some minor metalwork variations, all CD-80 upgrades work in all CD-80 racks, regardless of vintage. As noted above, very, very few AMX brains are still in use. The format didn't lend itself to large numbers of channels without a noticeable time lag, and the circuit boards themselves became flakey after ten or fifteen years of use. Most older CD-80 racks have been upconverted at least once, if not twice, since installation. I only have two AMX systems left in my area, and one of those is hard-wired touring packs, not the floor/wall rack.

Rebraining, either by Strand or by Johnson, will run you between $8,000 and $12,000 a rack. Nearly all of that is parts cost, labor is only an hour or two to physically swap the modules, barring other problems.

There is something of a market for complete racks, so you might want to check into that before selling off the rest of the modules. You mentioned another department taking some of the modules - do you have blank modules to replace them with, and maintain cooling airflow?

[DimmerDotCom]

Originally Posted by FatherMurphy

You mentioned another department taking some of the modules - do you have blank modules to replace them with, and maintain cooling airflow?

If you are missing that many dimmers it is often easier to have a piece of sheet metal made for about 60-80 bucks and remove the empty trays to maintain the airflow. At least you will have alot of spare conenctors and pins for the dimmer racks side if you should ever burn a socket.

[shiben]

Thanks for the info guys. The rack is an AMX control system, it has been installed in the facility since the early to mid-80s (not sure of the exact date), and has been working really well for us. I had heard of a simple card replacement that would deal with out main issue of having some lights come to full when the console was powered down, but other than that, the dimmers have been great. To answer some questions presented: raceways from the closet to the electrics would probably 3 or 4 inch EMT (or however it needed to be, thats for the spark to decide really), and we have a large amount of copper sitting around (we just built a large new facility, and have a lot of spare wire sitting around that the electrical installer didnt use or something). We have an AMX to DMX converter, so would that be the best option to use? Thanks for the help!

[rschwimmer]

I wanted to chime in on this one if I could.

CD-80 can range from about 20 years +++. I would honestly say that you should move the rack to the gym. You own most of the equipment already, USE IT.

The best thing for you to do is to upgrade the processor to a C21 processor. We have a retro-fit kit that would be perfect for you case.

Kit part number: 76698-0004
Kit includes the following:
CD80/CD80AE Retrofit Kit - Includes: (1) C21 96-Output Rack Processor Housing, wired for Single Electronics, (1) CD80/CD80AE Interface PCB, (1) 96-Output Rack Processor Module, (1) 76695-0003 Architectural Power Supply Kit, New Fan Assembly.

This option would allow you to keep your old modules, dust them off, and have basically a new rack with all new electronics, and then you can run it off DMX. Smartest move to me.