[Mr.Sneis]

This is way more complicated than I want it to be:
 
http://www.rane.com/note110.html
 
Basically methods 4 and 6 are confusing to me -- I have no clue how to tell if my source is a transformer or cross coupled output stage!
 
I dissected a monoprice version and evidently they use glue on the RCA end but it looks like they combine the shield and cold to the sleeve and hot to tip.  On the XLR end it looks like they bridged pin 1 and the the barrel (?), shield to pin 1, hot to pin 2, cold to pin 3.  It works but all of the sudden this cable is starting to worry me.
 
If it helps I'm trying to go from the balanced out of either an Apogee MiniDAC (I'm pretty sure there isn't a transformer in it) and/or the balanced out of a Sony XA5400ES CDP (which I am pretty sure is not a true balanced source).  Any help is appreciated!  If possible I just want to know if I go for method 4 or method 6 or rip off the monoprice method.

 

[Steve Eddy]

If the cable you're using now works and you're not getting a hideous amount of hum and noise, you should be fine.
 
se

 

[Mr.Sneis]

Wellp my goal is to have the two sets for the two sources ideally.  But this info floating around the interwebs seems to be highly conflicting.

 

[Steve Eddy]

Well if you want to play it as safe as possible seeing as you don't know exactly how your balanced outs are configured, go with 4.
 
se

 

[Mr.Sneis]

I wired up using method #4 from the rane note 110 and have some interesting findings.  I have maybe now 3 ways to go from balanced output of the source to unbalanced input of an amp.  I don't see this being discussed much here but I hope this may be an interesting experience.
 
1) Monoprice female xlr -> rca.  On the xlr side this one has shield to pin 1 which is also bridged with the connector barrel, hot to pin 2, cold to pin 3.  I have yet to see somehwere on the web where this is "recommended" wiring.
 
2) DIY female xlr -> rca.  This one I took a 4 conductor cable (diagram calls for 1 conductor), neutrik female xlr, canare RCA.  On the xlr side this one only has the shield to pin 1 and I then took the 4 conductors to pin 2, and nothing on pin 3.  On the RCA end 4 conductors to the tip and shield to the sleeve.
 
3) Hosa female XLR to RCA female stubby adapter (GXF 132) and some cheap off the shelf RCA stereo cable.  "XLR pin 3 is grounded resulting in an unbalanced signal." - what I can determine about the inside; which doesn't immediately compute into any usable info as far as I can tell.
 
Keep in mind my two sources are: Apogee Mini-DAC and a Sony XA5400ES which is a "fake" balanced out source (Sony apparently added XLR out as an afterthought and upon dissection appears that no true balanced output from the DAC exists). 
 
The interesting thing I find is that the Monoprice cable and my DIY cable seem to have a higher noise level than the Hosa female XLR to RCA adapter.  That is with no sound output and cranking the volume knob I have a better headroom until I hear hissing/humming on my amps with the Hosa adapters.  Also I am finding that with no connection to the amp (or an unused input) there is near inaudible line noise; in other words all of the above are creating some sort of line noise.  Luckily all 3 methods "work."
 
This leads me to believe that the way the adapter is wired up is probably the way I need to be making my cable.  The adapters are about $7 apiece and are pretty indestructible unfortunately so I don't think I will be able to dissect it anytime soon.  On the other hand, the fact that all IC's are making some noise has me a little concerned; it's a shame that my testing so far has been pretty unscientific!

 

[Mr.Sneis]

I think I could also try the diagram below (borrowed from another thread)
 
 
 
Quote:

Quote:

Originally Posted by revolink24 /img/forum/go_quote.gif Why does it matter? Get a balanced amplifier with unbalanced (RCA) inputs and you should be set.

Problem is that the C10 is only balanced (and it's a speaker amp FYI).

Are the adaptors really balanced though? Wouldn't something have to discern what the different polarities are and then put them into XLR as balanced?

Like here, the negative is just put into the ground, so it isn't really balanced.


And:
My speakers have a 50 - 300 watt min/max amp power rating, they are 6 ohms and if I get an amp with 375 W at 6 ohms will I destroy them if I don't blast them?

 

[Mr.Sneis]

Oh the plot thickens, but in a very expensive way:
 
http://www.markertek.com/Audio-Equipment/Audio-Processing/Audio-Hum-Noise-Eliminators/Jensen-Transformers/PC-2XR.xhtml
 
http://www.henryeng.com/matchbox.html
 
Seems like these boxes can solve the impedence mismatch causing my line noise.  Not sure I'm ready to take the plunge.

 

[nikongod]

Quote:

Wellp my goal is to have the two sets for the two sources ideally.  But this info floating around the interwebs seems to be highly conflicting.
 

 
 
Can you draw us a picture of what you did here? 
 
Quote:

Seems like these boxes can solve the impedence mismatch causing my line noise.  Not sure I'm ready to take the plunge.
 

 
The transformers arent really there to solve any impedance matching issues but to provide galvanic isolation. 
 
Maybe 3 people on head-fi have ever had an impedance mismatch issue between their amp and source. Stop saying it. 

 

[DingoSmuggler]

Both of those sources have single ended outputs, yes?
Why aren't you using those? That's what they are there for.

 

[Mr.Sneis]

Because I have more amps than sources...

 

[DingoSmuggler]

Maybe building a source-switching-box, or using a pre-amp would be a better idea then? not sure of your exact requirement, throwing ideas out there
 
If you're happy with the "hosa adaptor" performance, no need to dissect it, just plug the rca cable in it, then use a multimeter on it to see what's connected where.
If you don't have a multimeter, buy one, they're cheap and a must have, really 

BUT if the hosa adaptor shorts pins 1 and 3 together, i'd be a bit worried about using that method for your cables. Your sources might not like having their inverted(-) outputs shorted to ground.
 
 
 

On the other hand, the fact that all IC's are making some noise has me a little concerned; it's a shame that my testing so far has been pretty unscientific!

Hooking up lots of gear together can lead to grounding issues. (regardless of what your currently listening to, the grounds are likely to be all connected)
To be a little bit more scientific about it, unplug everything, and try each interconnect method in isolation, check the noise/hum performance of each by itself, then try adding more gear to the mix.