Control/Dimming Dimmer Doubling

[skienblack]

Whats the catch? ETC's dimmer doubling seems like a great idea if you already own their dimmers. And considering S4 are the standard ERSs, why wouldn't these be used more often? From what I gathered the 77v lamp outputs similar lumens.

 

[Footer]

The technology is used heavily in touring situation, especially for broadway shows. It cuts your dimmer rack in half and the amount of cable you have to run in half.

However, it does have a number of drawbacks. You have to purchase dimmer doublers and you SHOULD buy new basecaps with a twislock connector on them. Those basecaps are deamed "dimmer double only". However, many venues just convert their dimmer doublers over to stagepin and do lamp swaps which can get ugly if you don't keep tabs on it. The big thing is you have to completly buy into ETC. You can't use other units on the market and your dimmer doublers.

In new construction, I don't feel depending on dimmer doublers is worthwhile. In a retrofit situation where you are JUST swapping out the dimmers and you don't have the cash to pull more circuits, its not a bad way to go. It does add on more labor and more time. It is just one more thing that can go wrong in the system.

 

[skienblack]

Am I also correct in my understanding that the complete circuit with two 550/77v lights draws less current than two conventional fixtures on two circuits?

 

[Morpheus]

i thought that there was some sort of loading catch with dimmer doubling - wattage?

Anyway, what i basically understood is that it doesn't magically 'double' the number of lights you can have total, it just increases the control over the lights you can already use...

 

[MNicolai]

ETC's Dimmer Doubler Datasheet

That explains the gist behind dimmer doublers. They allow you to control both the positive and negative portions of the AC sine wave, distributing the positive to one fixture, and the negative to the other. While on paper it's an awesome idea that saves thousands of dollars, many people don't want to go through the hassle of it, especially if that means they have to worry about mixing up 120v and 77v lamps.

With that said, I have talked with at least one TD who is proud of what dimmer doublers have done for his venue. His stage is still 120v lamps, but he needed more circuits on his FOH catwalk. Rather than spending boatloads on new wiring and dimmers, he installed dimmer doublers. Because the fixtures [almost] never move between the stage and the catwalk, he has experienced no problems having both 120v and 77v lamps floating around. Now he can put more fixtures on his catwalk than he has room for.

 

[bdkdesigns]

The only catch is that you can't two-fer. I've also experienced two batches of bad lamps now, with different companies. We do not have a high turnaround on lamp usage either so that is not a good sign. Perhaps we have just been unlucky though. Our supplier has completely replaced both batches with new ones and we sent back in the dead ones and the unused ones from the same batch. One of them was confirmed as a fault in the design and we ended up switching companies. This latest batch just went in the mail so I'll never hear the story because I'm leaving in two weeks.

 

[xander]

While I have yet to ME a production utilizing dimmer doubling so I am not a expert, I have loaded in a lot of shows with it. Like others have said, you do have to go all ETC, so it is not something you can just add into the mix. Also been said, it does not magically double your capacity. What it does do though is double your control. It is very useful in smaller spaces where you rent an entire package-dimmers, distro, cable, instruments, etc-so you get all ETC dimmers and S4s. With dimmer doubling you can get the control of a 96 rack with a 48 rack while taking up half as much room (space is gold in NYC) and only running 8 multis instead of 16 (a labor and equipment savings). It is not some hidden treasure waiting to be discovered, but it is another choice that can be very useful in some situations.

 

[derekleffew]

CB Search results for "dimmer doubler."

From the wiki entry Dimmer Doubling :

Here is a thread where this was talked about at length.

 

[Footer]

The only catch is that you can't two-fer. I've also experienced two batches of bad lamps now, with different companies.

You can two-fer, you just have to ensure that you are within the capacity of the dimmer. It is possible to run 4 fixtures on one dimmer doubler.