Don Allen Posted December 20, 2013 Share Posted December 20, 2013 I cannot see how an interfering signal would come in on one of the paired sockets and go out on the other. The 75176 is set to transmit direction only, so it would have a high attenuation to any interference. It is true that there is no voltage isolation between each 3 and 5 pin output pairs, so a high voltage on one socket line could damage the other socket line, whereas there is voltage isolation between the four pairs. In the cases of switch mode power supply noise from one led par affecting other units, it is because the DMX in and out sockets of the units are wired in parallel. What I like about these units is that they save costs in adaptors as both 3 and 5 pin DMX outputs are available. Link to comment Share on other sites More sharing options...
Brian Posted December 20, 2013 Share Posted December 20, 2013 ...so it would have a high attenuation to any interference.Only to any differential signals; anything that causes causes a common-mode signal to appear on one set of connectors will cause it to appear on the others. Link to comment Share on other sites More sharing options...
timsabre Posted December 20, 2013 Share Posted December 20, 2013 ...so it would have a high attenuation to any interference.Only to any differential signals; anything that causes causes a common-mode signal to appear on one set of connectors will cause it to appear on the others. Such as stray voltages, e.g. wiring loom rubs through in moving head, puts +24V on the chassis which then puts +24V offset on the DMX signal. This will pass through onto both sides of the DMX output if you are using the 3 pin and 5 pin. Link to comment Share on other sites More sharing options...
Nicktaylor Posted December 20, 2013 Share Posted December 20, 2013 Its purely the paired sockets we are talking about and any signal interference would not get back as far as the 75176 to worry about it being one way, it would go up the other path and corrupt that DMX. Its all a bit theoretical but better safe than sorry. Whether a tiny amdram show with cheap movers or the biggest concert your credibilty falls off the cliff if things go wrong. Especially if you are cutting corners at the cheap end! Link to comment Share on other sites More sharing options...
dbuckley Posted December 21, 2013 Share Posted December 21, 2013 Here a dirt simple DMX buffer buried in a prop. A smoke machine we have seems to annoy other devices on the DMX line, so normally I just give it its own output off one of those Chinese 4/8 way splitters, and all is well. In a prop with just a single (wireless) DMX feed and half a dozen DMX devices, it was a little harder, and sure enough it didn't want to play ball, so I knocked up this ugly (non-terminated!) buffer, which worked a treat. It is no more than two SN75176s "back to back".. http://davidbuckley.name/pix/simples_dmx_buffer.jpg Link to comment Share on other sites More sharing options...
DanSteely Posted December 27, 2013 Share Posted December 27, 2013 The Thomann Stairville splitter is pretty much identical to one I got from BlueAran under the Soundlab brand. http://www.bluearan....de=manufacturer All of our DMX distribution at school is via 3-pin XLR and have made 5-3 pin jumpers so regularly use all 8 outputs on the splitter without issue. When I bought the Soundlab splitter a few years back it was over £100 but I now notice it's half that price.. IMO It's not worth the aggravation and cost of a home brewed solution.. Link to comment Share on other sites More sharing options...
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