RCA to balanced

"True, but then you are dealing with the limitations imposed by the transformer"
And the limitations of output coupling capacitors have no sonic consequences? Or OP amp buffers? Personally, I much prefer the "limitations" of a quality transformer to the other alternatives. But then I'm not in the business of selling OTL amps.

John-tracy is correct in that coupling caps have consequences -- don't all circuit parts? Ihe issue is which devices' "consequences" you think di the least harm, right?

For neutrality, I'd personally take today's high quality caps over step-up transformers any day -- but there was a time when SUT's were the only way to go, which I think might explain the huge numbers of them now available used.

Nsgarth, the discussion here was line out transformers, not MC input transformers. Although even here good SUTs are very competitive. For example the new Lundahl silver LL1931AG at $800/unit. That's performance competitive, maybe not price competitive as OP amps cost a few dollars at most. FYI, SUTs supply gain. Capacitors do not. That requires active circuits. That means transistors or tubes or OP amps. All of which have there own issues.

I don't usually think I can catch John in error, but in this case I think it's better to say that SUTs or any transformer, can alter the ratio of current to voltage of whatever is put into it. In the case of a SUT, voltage of the phono signal goes up and current goes down. This enables the cartridge's output signal better able to drive the downstream phono stage. Transformers per se do not supply gain. I am absolutely sure John knows this better than I. But readers can go off with the wrong idea.

Lew, the term "gain" is commonly used to refer to "voltage gain," the ratio of output voltage to input voltage. It is often (although not necessarily) expressed in db, corresponding to 20log(Vout/Vin). So in that sense transformers can supply gain, although as you realize they cannot provide "power gain" (i.e., they cannot increase the product (multiplication) of voltage and current).

Best regards,
-- Al