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#1
Posted to rec.audio.pro
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Balanced output to two inputs, one of which is unbalanced
From Rane Note 110, the archives of this newsgroup, and dim memories of
other things I've read, I've pieced together a partial understanding of cables to send a balanced output to an unbalanced input. As far as I can tell, unless the output is transformer balanced, "floating balanced", "cross-coupled", or "servo balanced", then I use: balanced Hot to unbalanced Hot balanced Cold is not connected balanced Shield to unbalanced Shield If the output is differential balanced, I lose 6 dB of level; if the output is impedance balanced, I do not. My question is this: suppose that the balanced output is also multiplexed to a second input using a wye cable, and the second destination is balanced. Is this going to cause problems, for example because the load impedance now differs between the hot signal and cold signal? (The hot signal sees the combined inpedance of two inputs, while the cold signal only sees one.) Or because of something else I haven't thought of? Thanks in advance for your help! --Bob Richard |
#2
Posted to rec.audio.pro
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Balanced output to two inputs, one of which is unbalanced
Bob Richard wrote: My question is this: suppose that the balanced output is also multiplexed to a second input using a wye cable, and the second destination is balanced. Is this going to cause problems No, as long as the balanced input is OK being fed from an unbalanced source. for example because the load impedance now differs between the hot signal and cold signal? Once you unbalance a source, it's always unbalanced. Tie the "cold" side of the balanced input to ground and pretend it's unbalanced. |
#3
Posted to rec.audio.pro
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Balanced output to two inputs, one of which is unbalanced
On 3 Jul 2006 17:54:30 -0700, "Mike Rivers"
wrote: for example because the load impedance now differs between the hot signal and cold signal? Once you unbalance a source, it's always unbalanced. Tie the "cold" side of the balanced input to ground and pretend it's unbalanced. The nature of his question seems to imply he intend to run the balanced device off of plus minus ground and the unbalanced off plus and ground. Unbalancing both signals as you suggest does seem to be a possible good solution. Julian |
#4
Posted to rec.audio.pro
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Balanced output to two inputs, one of which is unbalanced
"Julian" wrote in message
... The nature of his question seems to imply he intend to run the balanced device off of plus minus ground and the unbalanced off plus and ground. Yes, exactly. But Mike's response appears to say that it doesn't matter how I wire the two destination devices; the circuit as a whole will be unbalanced regardless. Correct? Thanks again for you help. --Bob Richard |
#5
Posted to rec.audio.pro
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Balanced output to two inputs, one of which is unbalanced
"Julian" wrote in message
... The nature of his question seems to imply he intend to run the balanced device off of plus minus ground and the unbalanced off plus and ground. Yes, exactly. But Mike's response appears to say that it doesn't matter how I wire the two destination devices; the circuit as a whole will be unbalanced regardless. Correct? Thanks again for you help. --Bob Richard |
#6
Posted to rec.audio.pro
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Balanced output to two inputs, one of which is unbalanced
Bob Richard wrote: Yes, exactly. But Mike's response appears to say that it doesn't matter how I wire the two destination devices; the circuit as a whole will be unbalanced regardless. Correct? "Balanced" (in the electrical context) is one of those words like "square" or "pregnant." Either it is or it isn't. If you have a bipolar output with equal voltages of opposite polarity with respect to ground and at the same source impedance, and connect this to a differential input, you have a balanced connection. If you then tap off the "high" side and connect that to another input, you've unbalanced your connection. The reason for this is that you've put the input impedance of your unbalanced input in parallel with the output impedance of the "high" side of the source, therefore unbalancing that path. You might be able to get it back to being balanced by connecting a resistor equal to the input impedance of your unbalanced input between the low side of the source and ground. But unless it's very accurately matched to the unbalanced load, you'll still be unbalanced. However, it might not be any worse than the balanced connection that you get with a single ended "impedance balanced" output. However, unless you're running long cables and have a lot of EMI, you're better off just treating your source as single-ended and hooking it to the two inputs accordingly. |
#7
Posted to rec.audio.pro
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Balanced output to two inputs, one of which is unbalanced
"Mike Rivers" wrote in message
ups.com... [...] If you have a bipolar output with equal voltages of opposite polarity with respect to ground and at the same source impedance, and connect this to a differential input, you have a balanced connection. If you then tap off the "high" side and connect that to another input, you've unbalanced your connection. Thanks! The new (to me) lesson here is that it is the whole circuit that is balanced or unbalanced, rather than any given output or input by itself. --Bob Richard P.S. I apologize for the duplicate post an hour or so ago. Outlook Express is not being my friend. |
#8
Posted to rec.audio.pro
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Balanced output to two inputs, one of which is unbalanced
"Bob Richard" wrote ...
Thanks! The new (to me) lesson here is that it is the whole circuit that is balanced or unbalanced, rather than any given output or input by itself. An individual input or output can still be capable of being balanced (by its inherent design), but once somebody grounds one side, nobody gets the benefit of a balanced circuit. P.S. I apologize for the duplicate post an hour or so ago. Outlook Express is not being my friend. More likely your NNTP server is not being your friend. OE (or any other news client) likely has nothing to do with it. Postings I make to the NNTP server here in the office show up *instantly* in OE. Postings I make to Supernews take many minutes to show up in the same OE. |
#9
Posted to rec.audio.pro
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Balanced output to two inputs, one of which is unbalanced
On Wed, 5 Jul 2006 18:46:42 -0700, "Bob Richard"
wrote: Thanks! The new (to me) lesson here is that it is the whole circuit that is balanced or unbalanced, rather than any given output or input by itself. --Bob Richard Not necessarily Bob. I suggested a way that you could run one device balanced and the other unbalanced, but I like Mike's idea better. Julian |
#10
Posted to rec.audio.pro
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Balanced output to two inputs, one of which is unbalanced
These are much a better idea and handle level control between +4 and -10
as well http://www.audiotelex.com.au/contractor.html#sc2 Cheers Goaty -- _--_|\ John Lamp - in beautiful downtown Highton / \ DoD#:1906 Ulysses#:10185 Vulcan Nomad \_.--._/ Phone: 0409 512 254 v Hear no Evo, See no Evo, Fear no Evo Militant Agnostic - I don't know and you don't either |
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