peter Posted January 15, 2003 Share Posted January 15, 2003 Hi A thought just occured to me as I've been asked to DSM a show where they want cast calls and headset calls, is there a way of converting (cheaply) between Beltpack 3pin XLR output from the master station to the 3pin XLR input on the mixer feeding the dressing rooms? I have a funny feeling the answer will be 'no' but I thought I'd ask anyway - might save me having to switch between headsets and fixed mics. Cheers Peter Link to comment Share on other sites More sharing options...
richard Posted January 15, 2003 Share Posted January 15, 2003 I don't think you can go via the three pin XLR, but I did once years ago make a bodge to link out of a 4 pin XLR (using a spare beltpack), you need to watch the gain on the desk and I don't know how much of a good idea it was, probably could do with a DI box somewhere, but I am not that good with sound so you might want to ignore me? Link to comment Share on other sites More sharing options...
Bryson Posted January 15, 2003 Share Posted January 15, 2003 I reckon that it probably be simpler just to bung a *separate* gooseneck mic into the mixer - with a switch, too. You really don't want to send the cans feed inadvertantly to the dressing rooms (or worse, FOH). That way, you can discuss the actors and audience without fear of reprisal. I know there's a technical joy in making one piece of technology do everything, (you should see my mobile...) but in this case, it's fraught with danger... PS: "Edit Post" is a joy - I can correct my spelling... Link to comment Share on other sites More sharing options...
Guest lightnix Posted January 15, 2003 Share Posted January 15, 2003 I'm not a noise boy either, but I asked this question once and was firmly told, "No !". The reason being that there's about 45 (?) volts on one of those pins, which would fry the input stages of the mixing channel. You might be able to 'pad' it, but Bryson's point is also spot on. It's best to keep the crew cans separate from everyone else, so there is no danger of any embarrassing cross talk. Link to comment Share on other sites More sharing options...
Rob Posted January 15, 2003 Share Posted January 15, 2003 You could put speaker stations in the dressing rooms if necessary and keep them on a separate ring of the comms system. Link to comment Share on other sites More sharing options...
Paul J Need Posted January 17, 2003 Share Posted January 17, 2003 Hi A thought just occured to me as I've been asked to DSM a show where they want cast calls and headset calls, is there a way of converting (cheaply) between Beltpack 3pin XLR output from the master station to the 3pin XLR input on the mixer feeding the dressing rooms? I have a funny feeling the answer will be 'no' but I thought I'd ask anyway - might save me having to switch between headsets and fixed mics. Cheers PeterI have actually done this with reasonable success for an outdoor Shakespeare festival - the dressing rooms where 300 yards (sorry Metres) away from the stage. and using a combination of Programme output from the comms PSU, a DI and a line balancing box it worked!!! Ok The cast could hear the chat on cans - which was not very often as the SM was within earshot of the audience.... so ...... the DSM was able to call the actors through her headset. Link to comment Share on other sites More sharing options...
Bob in Derby Posted January 17, 2003 Share Posted January 17, 2003 Just to stick my two euros worth in... Like Richard I knocked up something using the 4 pin connector from the headset - it wasn't exactly pretty and I've been meaning to tidy it up - maybe I will. The idea is to make up a box with 4 pin input, 4 pin output, but take a tap out from the 2 mic. channels, via a switch to a 3pin XLR (or jack if that is the system). The headset can then plug into the box, the box being plugged back into the beltpack and also the mixer / tie line as required. You could be a bit flash and make a lovely silent switch but it depends if you have the inclination I suppose! HTH - if it doesn't make sense I blame the wine, mail me and I'll try and send you a .jpg of some wiring Bob Rushton Link to comment Share on other sites More sharing options...
peter Posted January 17, 2003 Author Share Posted January 17, 2003 Thanks guys - I'll give the box building technique a try - probably have to be after this show though. You don't happen to know which pins carry the mic signal, do you? Cheers Peter Link to comment Share on other sites More sharing options...
Ben... Posted January 18, 2003 Share Posted January 18, 2003 This web page might be of interest;Tecpro interconnect specs;http://www.dmx512.com/web/comms/tecpro/tptech.htmAnd some other random circuit diagrams;http://www.dmx512.com/web/comms/tecpro/tptop.htm And if you're feeling really brave, the schematics for the standard beltpack are herehttp://www.beltpack.com/tec-bp1-schematic.pdf Link to comment Share on other sites More sharing options...
Andrew C Posted January 20, 2003 Share Posted January 20, 2003 You should be able to take a feed from the 3 pin, but as has been said above there are volts on one leg. (24 or maybe 48) Just don't connect that leg and treat the screen and remaining leg as an unbalanced source. I'm not sure of the top of my head what the level is or which leg is which and it may well be worth sticking a transformer in to isolate the two systems preventing hum. A pad may also be needed, but I don't think so. I've always wanted to do a show with the "talent" miming and the audience hearing the calls, cues and "technical descriptions" of the actors abilities/love lifes! Link to comment Share on other sites More sharing options...
Ben... Posted January 21, 2003 Share Posted January 21, 2003 You should be able to take a feed from the 3 pin, but as has been said above there are volts on one leg. (24 or maybe 48) Just don't connect that leg and treat the screen and remaining leg as an unbalanced source....just watch out for people pressing the call button - it raises the signal by 12v, which a lot of audio equipment won't like. Link to comment Share on other sites More sharing options...
Peter Russell Posted January 31, 2003 Share Posted January 31, 2003 Quite a few master stations or rack mount user outstations will have an output for a paging system that uses the headset microphone. It is turned on via a switch on the front panel, while this is active it mutes the mic through to the comms circuit, this may be more useful than an adaptor box as it will also have a volume control, Peter Link to comment Share on other sites More sharing options...
NickLee Posted February 2, 2003 Share Posted February 2, 2003 This is no use to you if your house system doesn't have this - and by the sounds of things it doesn't - but the Canford base station I usually use has a couple of lineouts for just this purpose, and I have linked that (3pin XLR) into a mixing desk before, and relayed it through to an auxiliary output on that desk (in this case, an amp connected to a monitor speaker backstage). It's a great feature if you ever need it, and it gives you that extra leeway - given the choice I'd always get a base station with this on even if I didn't need it at the time as inevitably it will come in useful sooner or later... Link to comment Share on other sites More sharing options...
James Posted February 4, 2003 Share Posted February 4, 2003 What you realy want is probably the AD903, the tecpro 2 wire to 4 wire interface, gives you line in/out and you can hire it from canford for £6 /wk. James Link to comment Share on other sites More sharing options...
Pete Alcock Posted February 5, 2003 Share Posted February 5, 2003 Peter, It's pretty straightforward. The standard intercom is an unbalanced system with ground on pin1, audio on pin 3 and power on pin2. The nominal audio level is around 100mV (about -20dBu). When you press th call button it puts 12V on the audio line. So, we need an attenuator to pad the level down to around -40dBu (mic level - to match the input of the amp), a capacitor to block the 12V DC when someone presses the call button, and so as not to load the intercom line the circuit must present a high impedance. From pin 3 of the beltpack circuit, put 1uF (DC blocking) in series with 47k as part of the attenuator, 4k7 to gound as a shunt to complete the attenuator, and feed this to pin 2 of the Amp's mic input. Circuit attached. Pete. Circuit Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.