Here's the link to the DD factsheet: http://www.etcconnect.com/docs/docs_downloads/datashts/DimmerDoubler_vF.pdf
Here's the link to the manual: http://www.etcconnect.com/docs/docs_downloads/manuals/DimmerDoubler_User_Manual_revA.pdf
The S4 Jr is a compatable fixture type, so you need X amount of HPL550/77 lamps, and X amount of dimmer doublers.
The rest assumes you have an ETC console as well as Sensor dimmers.
Essentially what you are doing is putting a 77 volt lamp into a fixture, with one 77v fixtures on ea half of the DD 2-fer (so they work in pairs, though you don't have to load both sides of a DD), you then assign specific Sensor dimmers to run in DD mode, which has one half of the dimmers sinewave output split by the DD, the upper half to one fixture, the lower half to the 2nd fixture. You then tell the console that you are running in DD mode. It splits a universe of DMX addresses into 1-256 as DD 1-256A, with DMX addresses 257-512 as 1-256B.
77v lamps run about $17, the DD is currently available as used from 4Wall/UsedLighting.com @ $89 ea., they say they have 35 available, and as they come from a reputable source, it's a steal. It's a good idea to maybe buy extra lamp caps for ea. fixture you want to DD, so the caps used for DD will have a twistlok plug as used by the DD 2-fer. Keeping the DD 2-fers at twistlok helps prevent damage and blown lamps. Or buy adapters.
Steve B.
[edited by: Steve Bailey at 8:30 PM (GMT -6) on Thu, Mar 26 2009]
Essentially what you are doing is putting a 77 volt lamp into a fixture, with one 77v fixtures on ea half of the DD 2-fer (so they work in pairs, though you don't have to load both sides of a DD), you then assign specific Sensor dimmers to run in DD mode, which has one half of the dimmers sinewave output split by the DD, the upper half to one fixture, the lower half to the 2nd fixture.
So, I know I am necroposting, but since Steve B. mentioned it in this post I thought it would count as related. :) I've done a fair amount of work with dimmer doublers in the past, but always counting on my ME (who really knows his sh**) to be the one to really have to worry about them. So, recently I was working on another show with DD with a different ME and the idea came up that you have to load both sides of the multiplexer. I was like, I've never heard of that or have had to do it in the past. They said that they had heard if you don't have a load on both halves, they wont work properly, like they wouldn't dim all the way, or wouldn't be as bright at full, or something. I argued that I didn't think that was true because I had never seen that before and I have done shows where I only put a load on one half of the multiplexer, but I don't really have the science to back that up. Is there any truth to this? If so, why?
There is no requirement to load both branches of the dimmer doubler. Essentially half the waveform goes to either branch of the doubler; the positive half of the waveform goes to one branch, the negative half to the other. Since the Sensor rack is upstream of the doubler, it always sees the full waveform, knows where the zero crossing is, and is, for all intents and purposes, immune to the presence or absence of a load on either side (or both sides) of the doubler.
The manual says there IS a safety requirement that load connectors be installed on both branches a dimmer doubler. This might be confusing your ME. It's the same as saying you should not have exposed wires sticking out of a receptacle.
There is no requirement to load both branches of the dimmer doubler. Essentially half the waveform goes to either branch of the doubler; the positive half of the waveform goes to one branch, the negative half to the other. Since the Sensor rack is upstream of the doubler, it always sees the full waveform, knows where the zero crossing is, and is, for all intents and purposes, immune to the presence or absence of a load on either side (or both sides) of the doubler.
The manual says there IS a safety requirement that load connectors be installed on both branches a dimmer doubler. This might be confusing your ME. It's the same as saying you should not have exposed wires sticking out of a receptacle.
