DMX splitter advice please

[attfield]

Can anyone on here recommend a reliable DMX splitter. I’m wanting to add DMX connectivity to 4 hanging bars and to sockets on the sides of the stage. A four to six way splitter so I don’t have to go up and down the bars with cable. Thanks

[sandall]

Lots to choose from, but try to go for one with opto-isolators on all outputs, rather than just one on the input.

[graemeftv]

we Manufacture 2 types DMX Buffers with FULL isolation between outputs, Dual 5 pin and 3 pin outputs

8/16 out  https://ultralightsound.co.uk/product/1-universe-DMX-buffer-ulsplit-16-outputs-in-a-1u-box/

and a 128output version

https://ultralightsound.co.uk/product/ulsplit-DMX-buffer/

[Gerry]

Hi attfield

Welcome to the forum.

I see you are, like me, an Amateur theatre practitioner, so I assume money is tight:

I have a Eurolight DMX splitter, about €100, and an unbranded one of these,https://www.aliexpress.com/item/1005005102820459.html?spm=a2g0o.productlist.main.11.4eeb41b2lnmS6N&algo_pvid=d71cc073-7f96-41ce-aff3-ca1cef33021f&algo_exp_id=d71cc073-7f96-41ce-aff3-ca1cef33021f-5&pdp_npi=4%40dis!GIP!30.31!19.4!!!38.61!!%40211b88ec16912512879615949e1813!12000033424843780!sea!GI!181883461!&curPageLogUid=yJjFDkV9XM9k bought off Ebay.

Both have worked faultlessly.

Cheers

Gerry

[sunray]

37 minutes ago, Gerry said:

Hi attfield

Welcome to the forum.

I see you are, like me, an Amateur theatre practitioner, so I assume money is tight:

I have a Eurolight DMX splitter, about €100, and an unbranded one of these,https://www.aliexpress.com/item/1005005102820459.html?spm=a2g0o.productlist.main.11.4eeb41b2lnmS6N&algo_pvid=d71cc073-7f96-41ce-aff3-ca1cef33021f&algo_exp_id=d71cc073-7f96-41ce-aff3-ca1cef33021f-5&pdp_npi=4%40dis!GIP!30.31!19.4!!!38.61!!%40211b88ec16912512879615949e1813!12000033424843780!sea!GI!181883461!&curPageLogUid=yJjFDkV9XM9k bought off Ebay.

Both have worked faultlessly.

Cheers

Gerry

I have a couple of the cheaper units and agree they have done exactly what is required. They don't have the opto isolation mentioned by Sandall however that has not been an issue.

 

To clarify the point they are fitted with opto isolators (I don't recall if 1 or 8 of them), but the electronics all works off the same supply and negates the isolation.

[david.elsbury]

2 hours ago, graemeftv said:

we Manufacture 2 types DMX Buffers with FULL isolation between outputs, Dual 5 pin and 3 pin outputs

8/16 out  https://ultralightsound.co.uk/product/1-universe-DMX-buffer-ulsplit-16-outputs-in-a-1u-box/

and a 128output version

https://ultralightsound.co.uk/product/ulsplit-DMX-buffer/

Hi Graeme- you may have missed my question to you from May7th. I know you don’t come to the forums a lot; so I’ll post it below. I just had a tech question regarding your amazing 128out splitter. Look forward to hearing from you ☺️ (copy pasted question follows)

 

>>

from your website : 

[quote]

8 DMX Universes 

8 isolated outputs per universe 

3pin and 5pin xlr for each output

Data led for each output

All the outputs are FULLY isolated. optically isolated and dc galvanic isolation. Meaning no matter what the fault on your DMX cabling or fixtures it is impossible for any of the other outputs to be effected 
[/quote]
 

so it appears you’re telling porkies; because 8 universes + 8 outputs per universe is 64; and there’s 128 sockets on this thing; so if you have a fault on output 1a (the 5 pin socket) it could actually affect output 1b (the 3 pin socket)?

of course if I’m wrong, I’d be more than happy to be corrected. Please, do tell ☺️

 

[gareth]

The website also states that the Ultrasplit "(costs) significantly less than 8 x budget 1u buffers" at £899+VAT. It's perfectly possible to find a budget 8-way isolated buffer for under £100 inc VAT these days.

It doesn't say whether it's RDM compatible.

Also, there's nowhere to stick some labels on the front panel to mark up what each output is feeding - I like everything clearly labelled.

Can anyone enlighten me as to what makes eight 8-output buffers in a big box "The worlds most advanced DMX distribution system"?

Edited August 6, 2023 by gareth

[partyanimallighting]

Not UK based but I've gotten great service from Elation splitters/boosters. If an output went down it was a simple repair via replacing an encapsulated transformer or a blown transceiver. The Chauvet Data Streams are fairly reliable too.

[attfield]

Thanks for the advice guys. Yes budget is an issue for us which will dictate which way we go.

A couple of  additional question, can you run splitters in series? i.e. split a line that has already been split.  And, I’ve assumed theatres use 5 pin XLRs but is there any reason why you couldn’t standardise on 3 pin?

[david.elsbury]

Yes you can absolutely daisy chain splitters. No issues with using 3 pin or 5 pin if you wish. It’s important to use proper DMX cable though, not mic cable, for best results- and using 5 pin helps enforce that a bit easier 🙂

[gareth]

As per David's post - you can chain as many splitters as you want, as long as you're chaining from an isolated buffered output and not a DMX Thru. An opto-splitter regenerates the DMX signal, so your device count limit is effectively reset.

Lots of cheaper kit uses 3-pin only, and dual 3- and 5-pin connectors are quite common - it works, but strictly speaking it's not compliant with the DMX standard. And the caveat about using the right kind of cable is important.

[sunray]

2 hours ago, attfield said:

Thanks for the advice guys. Yes budget is an issue for us which will dictate which way we go.

A couple of  additional question, can you run splitters in series? i.e. split a line that has already been split.  And, I’ve assumed theatres use 5 pin XLRs but is there any reason why you couldn’t standardise on 3 pin?

Early advice to me (actually by 3 different people) was to keep the splitters on the main DMX run and try to restrict the main run to the splitters so as little as possible sits directly on the desk. However the cheaper units linked to to by Gerry don't have any unbuffered output.

Assuming the buffered outputs faithfully regenerate (probably the wrong term) the input I can see no reason for doubt and I have successfully used 5 or 6 daisy chained in my tiny AmDram type systems with no perceived problems. Indeed Gareth offers exactly that as the best option.

 

Regarding the type of connector the first question should be; What connectors do you have on your lights? If they are all 3 pin then that is your standard. If you have a random selection of 3 pin and 5 pin you end up with a lot of cables; 3-3pin, 5-5pin, 3-5pin & 5-3pin or a boxful of adapters. In my case I have all 3pin except 2 dimmer packs so I changed those to 3pin and the Swisson which I have to accept as the oddball.

Edited August 6, 2023 by sunray

[Tomo]

3 pin XLR is explicitly prohibited by the actual ANSI E1.11 DMX512A standard, because cross-plugging audio and lighting is very likely to damage the equipment (or worse).

So, anything that is 3-pin (since 1990) was made by someone who either didn't read the standard or deliberately chose not to comply. What else did they omit?
Some 3-pin stuff also uses a different pinout. (Presumably because they didn't read the pin numbering on an XLR-3.)

In general, I would only chain splitter "thru", and not splitter "outputs".

This is simply because if the splitter fails, then everything on its outputs will stop working.
However, the "thru" is passive, so it's likely to still work after a failure.
Thus, if my splitters are connected via "thru" then everything on my other splitters should keep working until I've a chance to replug or swap the bad splitter.

I would also very strongly recommend fully-isolated splitters.
- Especially if you have some 3-pin (nonstandard) equipment, as the isolation should limit the damage if someone crossplugs and you get unlucky.

[Jivemaster]

Beware the odd "balanced mic cable" I've seen several with the screen and -ve signal wire connected by a deliberate solder blob. This really destroys a data + - and screen situation as for DMX across a whole group of lines.

[Stuart91]

On 8/12/2023 at 11:24 AM, Tomo said:

Some 3-pin stuff also uses a different pinout. (Presumably because they didn't read the pin numbering on an XLR-3.)

Some older Martin gear had a pin 2/3 reverse because Martin had their own multiplex standard prior to DMX becoming standard. It was similar enough to DMX that fixtures could use both but kept their own pinout. 

I suspect some other manufacturers chose to match this, caused headaches for me more than once. 

I've also seen som small controllers that have a switch which flips the polarity on the output. Saves a turnaround, but it's another thing for dry hire punters to fiddle with and cause problems.