ThomJ Posted January 11, 2006 Share Posted January 11, 2006 any ideas on this one - this is an input cable from twin phono to single XLR. I have tried verious configs some give different results with different kit? any diffinative answer? :unsure: Thom Link to comment Share on other sites More sharing options...
dbuckley Posted January 11, 2006 Share Posted January 11, 2006 any ideas on this one - this is an input cable from twin phono to single XLR. If the definitive question is "I need a cable that I can connect from the stereo line outputs of something like a CD player which has a medium impedence output (say 1K) at approximately line level to a device with an XLR unbalanced input (pin 2 hot) or mdeium or high impedence" then the definitive answer is: Purchase cheap phono-phone cable, chop off one end, common screens and connect to pin 1 of XLR, on each inner core add a 2k2 resistor and common the other end of both resistors to pin 2 of the XLR. Although not part of the definitive specification, you will find it all goes much easier if you use small resistors, and get some heatshrink that goes over the resistors so that the end of the inner, the solder joint, and the resistor become a single unit after shrinking. Even better, get some silicon sleeving to go at the other end so that solding the resitor to the XLR doesnt melt the heatshrink. Link to comment Share on other sites More sharing options...
paulears Posted January 11, 2006 Share Posted January 11, 2006 and link pin one to pin three else it doesn't work. Link to comment Share on other sites More sharing options...
dbuckley Posted January 11, 2006 Share Posted January 11, 2006 Good point Paul, there may well be a tranny in there which wont work without that link. And what I really forgot to say was "and make dammed sure that wherever that XLR plugs into doesnt supply phantom power" You have been warned Link to comment Share on other sites More sharing options...
Jivemaster Posted January 11, 2006 Share Posted January 11, 2006 Then there is the option to connect the screens to XLR pin 1 and both phono outers to pin 3 and both centres to pin 2. Then there are the off stsndard configs 1 - ground. 2 - left 3 - right If in doubt CHECK. Mis-applied phantom will destroy output stages Link to comment Share on other sites More sharing options...
valooz Posted January 12, 2006 Share Posted January 12, 2006 this is a link I used quite often when I started making my own cables... there are most of the regular cables there too.... http://www.mediacollege.com/audio/connection/XLR-rca-2.html It's worth adding to your internet fav's, it comes in handy.... Link to comment Share on other sites More sharing options...
Simon Lewis Posted January 12, 2006 Share Posted January 12, 2006 Then there are the off stsndard configs 1 - ground. 2 - left 3 - right Which when connected to a balanced XLR cancels out anything present on both channels ;-) Link to comment Share on other sites More sharing options...
Andrew C Posted January 12, 2006 Share Posted January 12, 2006 Then there are the off stsndard configs 1 - ground. 2 - left 3 - rightWhich when connected to a balanced XLR cancels out anything present on both channels ;-)But dead usefull if you need a CD player some way from an amp. Pair of phonos to XLR, long mic lead, XLR to phonos. Only important thing is to keep the screen on pin 1. Link to comment Share on other sites More sharing options...
paulears Posted January 12, 2006 Share Posted January 12, 2006 The biggest snag is labelling the damn things so you know what they are for. The version that allows stereo down a standard XLR is really useful, but damn annoying when you want the 'mono from stereo' version! I have started to use coloured Neutrik glands to identify my 12V power cables (4 pin XLRs), so I can pick them out of the rest in the cable box. Maybe I should use a different colour for audio non-standard cables? Link to comment Share on other sites More sharing options...
Simon Lewis Posted January 12, 2006 Share Posted January 12, 2006 But dead usefull if you need a CD player some way from an amp. Pair of phonos to XLR, long mic lead, XLR to phonos. Only important thing is to keep the screen on pin 1. I see your point... although this isn't a situation I've needed to handle, as I'd usually have the CD next to a desk.Do you encounter any problems with the CD player's medium impedance output driving a long line? The stereo to mono cancellation issue is one I come up against with church installs.... Church adds a CD player to its system, plugs a stereo jack into a balanced mono line in, then complain that the system is no good because it "sounds funny". Simon Link to comment Share on other sites More sharing options...
bruce Posted January 12, 2006 Share Posted January 12, 2006 Do you encounter any problems with the CD player's medium impedance output driving a long line? I've seen this done fairly often - one of our "favourite" applications for this is when installing a data projector in a lecture theatre, with simple inputs for laptop and DVD/VHS. If we want to avoid using an AMX/Procon/etc controller, what we tend to do is use the projector as an audio switcher, and cable both the laptop audio and DVD audio, stereo unbalanced, back to the 2 corresponding audio inputs on the projector, and then from the audio out to an amp - often little more than a domestic hi-fi amp. So you've got unbalanced audio lines, being driven from a DVD output, which are perhaps 10m long. Sometimes much longer, maybe nearer 30m, although we would normally only use this method in small installations. This means that you don't need to worry about a separate switcher or mixer for the audio - it just "follows" whatever video source you select with the projector remote. Yes, I know it's bad practice. Yes, I know it's not the best way of doing things. But it works surprisingly well, as long as you use decent quality cable, and for many of our applications, it's more than "good enough". Bruce. Link to comment Share on other sites More sharing options...
StevieR Posted January 12, 2006 Share Posted January 12, 2006 http://www.mediacollege.com/audio/connection/XLR-rca-2.html Had a quick look at this link and realised that this really isn't good practice. If, from what they are suggesting, the input is coming from the XLR end and being split to 2 x Phono AND also assuming that the input is balanced then the output on the Phono's will be out of phase. Connect them up to a pair of loudspeakers and you'll get some strange results. Similarly, reverse the signal path with the Phono's as inputs and you will get some strange cancellation effects at the other end. I would recommend that XLR's NEVER get used for Stereo signals- only for Balanced ones. TRS Jacks are a different matter and cables need clear labelling to indicate whether they are a Stereo Split or a Y-Split. Steve Link to comment Share on other sites More sharing options...
Andrew C Posted January 12, 2006 Share Posted January 12, 2006 AND also assuming that the input is balanced It states quite clearly that it isn't! A 3-pin XLR with a stereo signal can be split into left and right by wiring pin 2 of the XLR to the tip of one RCA plug, and pin 3 of the XLR to another RCA tip. Pin 1 of the XLR connects to the sleeve of both RCA plugs. Link to comment Share on other sites More sharing options...
paulears Posted January 12, 2006 Share Posted January 12, 2006 I can't really see the problem - an XLR is a tough reliable connector, certainly much better than 3 circuit 1/4" jacks, which have always been used for both stereo or balanced connections. You just have to make sure you plug the right kit onto the ends. In fact one of the daftest installations was where all the desk mic inputs ran through a jack patch. Made patching multiple sockets around the venue easy, but idiots often plugged equipment in to them and shot 48V up the spout. Many did not like it up 'em, as the old saying goes. Link to comment Share on other sites More sharing options...
valooz Posted January 12, 2006 Share Posted January 12, 2006 I hadn't actually realised that the idea was to sum up the L and R channels... I use this cable as a trick for small events like a conference, where the organisers hadn't warned me that they wanted a cd player on stage.. I just use a 2 phono to XLR, then an ordinary mike cable as an extension, then a XLR / 2 jacks to hit the desk at line level... it's not textbook, but it's saved the day a couple of times...I must add that I have thes cables clearly marked, and I keep them in my Personal case, to avoid anyone plugging them into wrong places... Link to comment Share on other sites More sharing options...
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