DMX/analogue

[timtheenchanteruk]

Hi all, bit of advice please.

 

Where I work is council owned, but rented by us.

 

current setup is, really old lights (Patt45s, 123, 23, floods)) run form 2 Strand Mini II racks, and a tempest desk)

 

We want to get a new desk, and are investigating this, would the best(cheapest) way be? to get our own racks, and desk, or to look at DMX to -10V converters? and what would be the drawbacks to each method?

 

The only power avaliable is 2 32A Single Phase Sockets, and whatever 13A ring sockets we can find.

[gareth]

Sorry, old chap, but there's far too little information in there to enable people to give you useful advice. Who is "us"? What sort of shows do "we" do? Are "we" permanent tennants at this venue, or occasional hirers? How much funding is available to "us" for this project? How big is the performing area? Are you looking to install an infrastructure into the venue, or get something totally portable? And a hundred other questions ....

[Paul Roberts]

Regarding the DMX/Analogue conversion - might be tricky. The input to Mini II's is an octal connector; getting a demux thats outputs analogue to that will be near to impossible (someone please correct me if I'm wrong, but with octal connectors not having been used in lighting for many years I'm guessing I'm right on this one).

[musht]

Odd shaped octal and DIN plugs can be bodged around by

using pins out of plug that are appropriate fit, solder up pins to cable,

apply cling film/polybag to mystery socket

poke pins through plastic into socket.

Use some epoxy putty,JB weld etc to form ergonomic plug around pins in socket.Extra points for using sawn off pipe for plug housing or sculture skills....

Allow to set, remove custom plug and discard plastic film.

 

Only for use on low voltages.

[maeterlinck]

There are ways around any problem, it just depends on what you are trying to achieve. You setup sounds fine (assuming it's fully working) given the right sized space and programme. Tell more and perhaps we can give you some worth while advice!

[themadhippy]

. T

he input to Mini II's is an octal connector; getting a demux thats outputs analogue to that will be near to impossible

really? If the system is already in use its a fair bet theve already got the connectors to plug into the dimmers,cut the cable off at the desk end and connect to a suitable connector for the demux.

A 72 channel demux will cost around £100 for a 72 channel model,the only drawback I can see in doing this if you add dimmers in the future you'll either have to get dimmer with a DMX input,or anolouge - volt as the demux dosnt give different polarity's for different channels

[bruce]

Regarding the DMX/Analogue conversion - might be tricky.

The DMX/analogue conversion will be straightforward - just make sure you've got a demux that can do -10 output.

The input to Mini II's is an octal connector; getting a demux thats outputs analogue to that will be near to impossible (someone please correct me if I'm wrong, but with octal connectors not having been used in lighting for many years I'm guessing I'm right on this one).

 

Most of the "old hands" in the lighting business will have a few octal connectors lying around their junk boxes... and probably some converters from octal to din/bleecon.

 

Take 1 plug, 1 din/bleecon/whatever, some wire and 5 minutes with a soldering iron, and hey presto...

 

The plugs are difficult to source new, but turn up regularly on Ebay for a couple of pounds (check the "old valve-based radios" adverts). The sockets are available from RS, CPC and all the rest. You can even bodge an adaptor using an 8-pin relay base. Search this forum for "octal" for more clues.

[springgrove]

This all does depend what your budget is. In a similar situation with an am-dram group, because the Mini II dimmer packs needed a bit of attention, I decided to go to +10V analogue, gradually buying kit on eBay as it became available at a good price. There's quite a lot available. if you are prepared to wait. The Mini IIs will have some resale value.

 

It is possible to get voltage converters (positive/negative) or, if you are interested in electronics, they are easy (if a little tedious) to make, using quad opamps configured as inverting amplifiers with a gain of -1.

 

As someone has said, most demuxes will give a -10V output (though check before you buy). This will mean that you can make the first step into the wonderful world of DMX, although I am not sure that this is a big advantage in a 12 channel situation. Just remember that you can do a lot of fault-finding on analogue with nothing more complicated than a voltmeter!

 

If you are going to keep the Mini IIs, my inclination would be to fit them with 8-pin DIN sockets - a relatively easy job with a hole punch and a soldering iron. It is possible to find the octal plugs on eBay (and Lancelyn used to stock them, but they are very annoying when the locating pin breaks off, as it usually does!

 

Nigel

[boatman]

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If you are going to keep the Mini IIs, my inclination would be to fit them with 8-pin DIN sockets - a relatively easy job with a hole punch and a soldering iron. It is possible to find the octal plugs on eBay (and Lancelyn used to stock them, but they are very annoying when the locating pin breaks off, as it usually does!

 

Nigel

 

You can make an octal plug from one of these and one of these. Total cost <£2

[Paul Roberts]

really? If the system is already in use its a fair bet theve already got the connectors to plug into the dimmers,cut the cable off at the desk end and connect to a suitable connector for the demux.

 

I stand corrected. Thanks for clearing up my dodgy information.

[dbuckley]

Some advice also to be found here.

[mbthegreat]

Sounds a very similar setup to where I volunteer, except we have an analogue sirius (joy) and 4 betapacks. When we upgrade (soonish hopefully) we are just going to go for DMX dimmers at the same time we get the desk (especially as one of the dimmers is only working intermitantly).