[Charles Calkins]

My preamp does not have balanced output but my amp has them. Would there be any advantage getting cables made that would be balanced going into the amp and unbalanced coming out of the preamp.

                            Cheers
                            Charlie

[Glen B]

My preamp does not have balanced output but my amp has them. Would there be any advantage getting cables made that would be balanced going into the amp and unbalanced coming out of the preamp.

                            Cheers
                            Charlie

There would be no benefit.   The signal going into the amp will still be single-ended, same as with RCA connections.    You would just be wasting money on adapter cables.  In fact, depending on whether your amp is truly balanced or not, you could actually get worse performance by using the balanced inputs.

[Rivendell61]

Charles,
Your intuition is right.  Use the differential input to create a balanced connection.  (assuming your power amp input is truly 'balanced': ask the manufacturer).
Do not use an XLR adapter on an RCA cable.
The correct way is (Blue Jeans Cable can do this) have a shielded twisted-pair (like Belden 1800F) terminated at the RCA (preamp) end with the cold lead and shield tied together.  Terminate the XLR/balanced end as appropriate (again, check with manufacturer).  You now have an essentially balanced connection--
(Also, make sure you have appropriate low impedance output of pre vs high input impedance of power amp.)

Mark

[oris98]

Hi Mark,

What is the difference between your suggested way compared with a RCA-> XLR adapter ?   Will your method provides the advantage of balanced configuration even though one end is terminated with RCA plug ?   For left and right channel, are both channel should tie the cold and shield together ?  Someone has suggested one side should be cold and shield and the other side should be hot and shield for the RCA termination.  Also at the speaker connection one side should be black and red reversed.
Is this ture ?

Many thanks in advance..

[art]

I have made this suggestion here before, but let me do it again.

There is a guy, that can be found on another forum, that sells Jensen transfomers in a wooden box (sometimes called a "canary coffin"), that would work well for this. He is not a friend of mine. In fact, I can not stand the guy. But, that would be the best solution to get balanced performance out of a single-ended preamp.

OK...better still.......make your own, and save $$$. The transformers are around $70/each. But worth it.

Pat

[Rivendell61]

Hi oris,
Yes, the cable I described acts as a balanced cable (at least re noise rejection).  Keep in mind that the common audio description of a ‘balanced cable’ as carrying two audio signals is not true.  A balanced cable is defined as simple having equal impedance on both conductors (and that is what provides noise rejection).

The reason for my suggesting not using an XLR adapter on a RCA cable is simply that it wastes the functionality of the balanced input—you get no benefit: zero noise rejection when using the adaptor.

Art’s suggestion of a transformer would also work.  Although the default preferred choice seems to be the cable modification.  If you use the modified cable and find you still need more noise rejection you might try a transformer (I believe a Faraday shielded input transformer is what to look for).

Mark