dbuckley

Very handsome looking product...

I can't e the only member who already has access to enough intercom kit so doesn't need to build "ordinary" comms, but sees the blue clone boards as a way of building something around them, something different hat suits my needs, but with the difficult bit of the interfacing done.

Either end will do. You are doing what I thought you might be doing, and in large buildings the concept of "earth" is a bit variable, so keeping audio and earth separate is a wise thing to do. I'd put the transformer at the receiving end, but one at each end even better. Desk line outputs are quite hardy and so will drive line quite happily over the cat5, with the transformer just cleaning the earth at the receiving end. Neutrik make nice line transformers which have affordability on their side, as such things go. If quality not so important then Jaycar MA1512 just fine, and I use something even cheaper and nastier on my stage relay box. The only thing with transformers is they can saturate, and generally, cheap transformers saturate before more expensive transformers, particularly lower frequencies, so trade level for LF response and distortion, or buy more expensive transformers. Compare the Neutrik NTE1 and NTL1 specifications for level, -3dB versus +19dB at 50Hz, so if you want to transmit 30Hz you'll need a lower level again. Apply HPF for 75hz, and the handle-able levels go up. E2A - with balanced and transformers, you can use all four pairs.

If line level, no earth will be ok most of the time, particularly with transformers at one or both ends. Mic you probably want he earth.

Paying more is God's way of telling you that you are not ordering in big enough quantities :)

This is a problem by design; ClearCom and Technical Projects decided upon different levels for mic insert signal, and so anytime you mix packs, you mix philosophies.

Suggestion: could audio in and out be provided on unpopulated pads on the PCB so as to make the incorporation of the PCB into non-conventional applications easy, sort of a halfway to the AD903?

Me to a tee... Well done guys. And its very cool you've stepped up beyond a copy of someone else's design.

Its worse than that, I'm afraid. The software author ceased development some time ago, and although he's alive and well, and enjoying himself (I stalk him from time to time), he appears to have no interest whatsoever in PCStage. Until recently you have been able to buy the interfaces from the UK manufacturer and distributor. The current situation is that these interfaces are - today - no longer available for sale, however the distributor hopes that they will be available again one day. I have several emails and web site form contacts from people who want to buy interfaces, including Mr Dean the OP, which I from time to time pass on to the distributor.

The other possibility is to note that one can make gobos out of brass or copper, and the process for doing it is no different to making a PCB, except that one has to coat the metal with resist oneself, unless someone knows of a source of pre-sensitised brass or copper sheet. Schools often have the kit to make PCBs, especially the hard stuff like etching tanks with evil chemicals in them and a decent UV exposure box. One can get spray-on resist such as Electrolube PRP (usually part number PRP200 for the 200ml spraycan) from the usual suspects, which was intended for coating non-presensitised PCB material, but that stuff went the way of the ark. Rather than double-side coating the metal blank with resist, it should be possible to coat the non-exposed side with paint, lacquer or something similar. The secret to making good PCBs (and by extension, gobos by the same method) is have a good master film, and Mega Electronics LaserStar film and a 600dpi laser are the right things to use. If anyone has a go at this, do report how you get on.

+1

Certainly not the "Only". TheatreLight here in New Zealand have done 120 channel boards with fader-per-channel for decades, and they are still in production, should you feel the need to manhandle all those faders... For rock and roll busking with parcans, this kind of board is still unbeatable :)

'Course they wouldn't. 'Cos that would be awesome :) What a lovely, simple piece of engineering. E2A - 25 videos in the channel... that's my morning gone...

Absolutely need to check - the RTS standard for intercom signals is different to the ClearCom Party Line and very non-compatible. However, the old RTS company got bought, so who knows, their newer kit may be able to operate with PL lines. 'tis a real pity about signal incompatibility, 'cos RTS kit rocks. The telly boys love it to death...

<stunned>...

Yes, you can, I think there is such a breakout lead in the ClearCom product range somewhere to go on the end of the cable with six pin XLRs. ClearCom is compatible-ish with TecPro, but the levels are a little different, but I cant remember which way! But it works. I use a ClearCom master station with Production Intercom beltpacks and no-one complains! Note that if you have a fifty station party line then impedence differences between the different manufactures make stability a problem, but at the dozen station level its all fine. BEWARE - there are two different sorts of six pin XLR that are non-interchangable!!!

You may not like or choose to use the correct terminology, but its what the intercom and IFB industry calls what you call an auxilliary input. Products: ClearCom Encore 602 in the modern range. Many older ClearCom beltpacks with six pin XLR have been able to do programme in, though prior to the modern stuff it was a hardware mod. Now its a software "mod". Yes, these packs also have a 2.5mm jack for an extra headset but thats nothing todowith programme in. If you fancy something that sits on a desk rather than on your belt then most of the master stations allow individual programme in. I commonly use an older (cant remember the model number, the predecessor to the CS222) ClearCom two channel stage managers console that has programme in which can go to any combination of places, including just my ears. I also have a 1u 2 channel rack station with programme in. Alternative options include the AB-100 announcers console, which can do what you want (and more besides) or if you want the best audio in the intercom universe then have a look at the Studio Technologies 230 announcer console. Surprised Mac hasn't chimed in here, although I know the intercom stuff pretty well, he's about fifty times better than I am at this stuff!

The AD903 is exactly what the OP doesn't want, it puts external audio onto the comms line, but the OP wants external audio to his ears only. To the OP - you've not found what you want because you dont know the right magic words to describe "auxilliary input" - it is called a programme (or program) input. Many intercom beltpacks have this feature, look at ClearCom for examples. Sadly, the UK most popular Production Intercom and TecPro systems dont, so either a hacking or a bodge box is called for.