Balanced vs RCA between amp/preamp

@atmasphere 

"  You don't need transformers, but without them supporting thebalanced starndard get a lot trickier. We devolopd a means that is direct-coupled and yet floats the same way that a transformer winding does"

     I want to know the detail of your means. Could you please explain. Thanks!

@runwell Yes. We patented the use of a Circlotron output (which is direct-coupled and balanced) with a servo control to prevent DC Offsets from appearing at the output. The Circlotron is a push-pull circuit that allows for entirely symmetrical operation using a pair of tubes to drive the output. In our case we use 6SN7s for that task.

A Circlotron circuit employs floating B+ power supplies and so can have one side grounded or in the case of balanced output, both sides floating with equal impedance to ground, while at the same time not using the ground for anything to do with the signal. In this way it allows a direct-coupled tube output to support the balanced standard, AES48.

@ atmasphere

           Are you talking the connection between RCA preamplifier and XLR power amplifier ? or the circuit inside the amplifier?

          I just want to have a solution between RCA pre and XLR power amp, it seems the transformer coupled is the simple way to go.

    I just want to have a solution between RCA pre and XLR power amp, it seems the transformer coupled is the simple way to go.

It is. A set of Jensen ISOMAX line transformers should do the job. They make one that has RCA inputs and XLR outs.

https://www.jensen-transformers.com/home-theater/audiophile/

They make them to order too- so you can get RCA in and XLR out although you don't see that on their site.

@ atmasphere

        Thanks! I put the order a few days ago and will receive very soon.

So finally it goes down to the transformer isolation,it seems the usual way even the XLR output from the pre,they usually get the rca signal first and use the transformer to get the inverse signal and consist the XLR sigjnal. 

Am I right?