unbalanced to balanced


2018-04-17 6:50 pm
This was posted a short time back.


  • quasi-balanced interconnections.gif
    quasi-balanced interconnections.gif
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A balanced cable carries 2 identical signals out of phase. This is often the exact same signal as on an RCA cable but with only one phase present.

So... with TRS and RCA connectors...

Balanced output to RCA input
Sleeve ---> RCA Shield
Ring ---> not connected
Tip ----> RCA Center

RCA out to Balanced input
RCA Shield ---> Sleeve
RCA Shield ---> Ring
RCA Center ---> Tip

These are not ideal connections --it is always best to connect like to like-- but in a crush they do work.
The best "enginerical" way is to use any of the fully-differential amplifiers (FDA). This will provide you with a couple of benefits, but will demand to have a supply.
Having a proper source, without dramatical rise of THD at comparatively low load, you can use datasheet connection of THS4131 like first attached, while badly designed sources could demand for high-input impedance instrumentation amplifier to be placed instead of the FDA like last attached. IMG_20191226_083055.jpg IMG_20191226_083525.jpg


Disabled Account
2002-12-22 2:13 am
Calgary, Alberta
I can't believe how many threads are on this topic and how they continue to include misinformation all the time.
Balanced and Differential
"Balanced signaling is two conductors (with an optional shield) that have equal impedance to ground.

Differential signaling is two conductors (with an optional shield) transmitting the same signal at opposite polarity."
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