Community Theater Green Room Discussion Board: DMX control cables

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Dudecar101
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Topic: DMX control cables
Posted: 9/16/05 at 3:41pm

OK, first off, im a lighting designer this year at my school and have been asked to choose a light board for our theatre. SO I chose the ETC Expression 48/96, but supposedly the board has DMX inputs, and i am working in a 19 year old theatre. I doubt we have the DMX inputs, upon looking at the present lightboard (an analog lightboard) I noticed it is a cord that has a screw end and a whole bunch of pins...

AM I srewed or is there a series of adapters I can use to solve my dilemna, or am i an idiot and this is a DMX cord

Im a great 11 student whose a lighting designer...if you got ideas...send em!

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dougb
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Posted: 9/18/05 at 12:11pm

The question is what input your dimmer packs need. As soon as you know that, you can search on the internet for converters. There are lots of DMX to CMX converters and even DMX to AMX converters. The last time I bought one was several years ago and a DMX/CMX converter was around a couple of hundred dollars but I think they have probably dropped in price.

I think you are going in the right direction with the ETC Expression - it seems to be a very popular board - provided you can interface it to your dimmer packs. ETC can probably help you too - this is not the first time this question has been asked.

P.S. DMX uses five pin XLR connectors.

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Dudecar101
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Posted: 9/18/05 at 2:18pm

In the event that the old 20 year old dimmers needed to be replaced, how much do you think that would cost...there are 48 channels and we like to double up the channels so we have two lights on the same channel to give a feel of symetry.

Not to mention the hours of running new cables...

Im a great 11 student whose a lighting designer...if you got ideas...send em!

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dougb
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Posted: 9/19/05 at 11:49am

Dimmer packs are the expensive part of the solution - I have never bought new packs and used ones go for $100 or more per channel. On the plus side, a good dimmer pack lasts forever. Since DMX 512 has been the standard for several years, you can mix and match dimmer pack manufacturers if you have to.

The wire called for in the DMX 512 spec costs over 50 cents a foot. We have had very good luck with Cat 5 computer wire to run our signals 100 feet and slightly more.

Many theaters do what you are doing - replace one component at a time. We are a super low cost operation. I let other nearby theaters know what we need and we are usually successful although sometimes we have to wait for it. Our seats were donated by a nearby theater. We bought a used 24 channel light system (light board, dimmer pack and wiring) for $2,000 from a theater that was upgrading and we just bought a five year old velour curtain exactly the size we wanted in almost perfect condition for $200.

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Shatcher
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Posted: 9/19/05 at 3:28pm

the dealer you buy the board from should help you solve this problem. ETC will help as well. You will like this board. programing is pretty easy to use and ETC makes adapters for everything.

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dougb
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Posted: 9/20/05 at 11:10am

Just a thought:

The DMX specification calls for five pin connectors and wiring (four wires plus ground) but as of today only three wires are actually used (two wires plus ground). You could get 5 to 3 pin adapters (or just wire the 5 pin connectors with shielded two conductor) and use two conductor shielded cables (mike cables for example) realizing that some day you will have to replace them when the spec writers can agree on a use for the other two wires.

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Dudecar101
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Posted: 9/20/05 at 9:34pm

The ETC is a very nice board, i actually learned how to program and run one this summer at a theatre camp i attended. I like this board and that is actually a pretty good idea, because XLR 3 pin wire is much less than the 5 pin...

How does this Category 5 cable system work...cuz your right dimmers are expensive

Im a great 11 student whose a lighting designer...if you got ideas...send em!

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dougb
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Posted: 9/21/05 at 11:25am

Cat 5 is wire used for ethernet computer networks. It is unshielded, has 8 conductors (four twisted pairs) and has a surprisingly wide bandwidth that seems to work well for our lighting system.

For what it is worth, I am beginning to see ethernet based lighting networks - the signal is sent as an ethernet signal (generated by a computer rather than a light board) and not converted to DMX till the last few feet.

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Author	Message
Dudecar101 Walk-On Joined: 9/16/05 Location: Canada Online Status: Offline Posts: 0	Topic: DMX control cables Posted: 9/16/05 at 3:41pm
	OK, first off, im a lighting designer this year at my school and have been asked to choose a light board for our theatre. SO I chose the ETC Expression 48/96, but supposedly the board has DMX inputs, and i am working in a 19 year old theatre. I doubt we have the DMX inputs, upon looking at the present lightboard (an analog lightboard) I noticed it is a cord that has a screw end and a whole bunch of pins... AM I srewed or is there a series of adapters I can use to solve my dilemna, or am i an idiot and this is a DMX cord
	Im a great 11 student whose a lighting designer...if you got ideas...send em!

	IP Logged

dougb Celebrity Joined: 3/30/04 Location: United States Online Status: Offline Posts: 148	Posted: 9/18/05 at 12:11pm
	The question is what input your dimmer packs need. As soon as you know that, you can search on the internet for converters. There are lots of DMX to CMX converters and even DMX to AMX converters. The last time I bought one was several years ago and a DMX/CMX converter was around a couple of hundred dollars but I think they have probably dropped in price. I think you are going in the right direction with the ETC Expression - it seems to be a very popular board - provided you can interface it to your dimmer packs. ETC can probably help you too - this is not the first time this question has been asked. P.S. DMX uses five pin XLR connectors.
	IP Logged

Dudecar101 Walk-On Joined: 9/16/05 Location: Canada Online Status: Offline Posts: 0	Posted: 9/18/05 at 2:18pm
	In the event that the old 20 year old dimmers needed to be replaced, how much do you think that would cost...there are 48 channels and we like to double up the channels so we have two lights on the same channel to give a feel of symetry. Not to mention the hours of running new cables...
	Im a great 11 student whose a lighting designer...if you got ideas...send em!
	IP Logged

dougb Celebrity Joined: 3/30/04 Location: United States Online Status: Offline Posts: 148	Posted: 9/19/05 at 11:49am
	Dimmer packs are the expensive part of the solution - I have never bought new packs and used ones go for $100 or more per channel. On the plus side, a good dimmer pack lasts forever. Since DMX 512 has been the standard for several years, you can mix and match dimmer pack manufacturers if you have to. The wire called for in the DMX 512 spec costs over 50 cents a foot. We have had very good luck with Cat 5 computer wire to run our signals 100 feet and slightly more. Many theaters do what you are doing - replace one component at a time. We are a super low cost operation. I let other nearby theaters know what we need and we are usually successful although sometimes we have to wait for it. Our seats were donated by a nearby theater. We bought a used 24 channel light system (light board, dimmer pack and wiring) for $2,000 from a theater that was upgrading and we just bought a five year old velour curtain exactly the size we wanted in almost perfect condition for $200.
	IP Logged

Shatcher Celebrity Joined: 2/21/05 Location: United States Online Status: Offline Posts: 251	Posted: 9/19/05 at 3:28pm
	the dealer you buy the board from should help you solve this problem. ETC will help as well. You will like this board. programing is pretty easy to use and ETC makes adapters for everything.
	IP Logged

dougb Celebrity Joined: 3/30/04 Location: United States Online Status: Offline Posts: 148	Posted: 9/20/05 at 11:10am
	Just a thought: The DMX specification calls for five pin connectors and wiring (four wires plus ground) but as of today only three wires are actually used (two wires plus ground). You could get 5 to 3 pin adapters (or just wire the 5 pin connectors with shielded two conductor) and use two conductor shielded cables (mike cables for example) realizing that some day you will have to replace them when the spec writers can agree on a use for the other two wires.
	IP Logged

Dudecar101 Walk-On Joined: 9/16/05 Location: Canada Online Status: Offline Posts: 0	Posted: 9/20/05 at 9:34pm
	The ETC is a very nice board, i actually learned how to program and run one this summer at a theatre camp i attended. I like this board and that is actually a pretty good idea, because XLR 3 pin wire is much less than the 5 pin... How does this Category 5 cable system work...cuz your right dimmers are expensive
	Im a great 11 student whose a lighting designer...if you got ideas...send em!
	IP Logged

dougb Celebrity Joined: 3/30/04 Location: United States Online Status: Offline Posts: 148	Posted: 9/21/05 at 11:25am
	Cat 5 is wire used for ethernet computer networks. It is unshielded, has 8 conductors (four twisted pairs) and has a surprisingly wide bandwidth that seems to work well for our lighting system. For what it is worth, I am beginning to see ethernet based lighting networks - the signal is sent as an ethernet signal (generated by a computer rather than a light board) and not converted to DMX till the last few feet.
	IP Logged

Topic: DMX control cables( Topic Closed)