The majority of amps and preamps only have balanced inputs/outputs, but not true balanced circuit topology. I
believe that Krell, Mark Levinson, BAT, Aragon, Jeff Rowland, Pass, possibly Simaudio, Classe, have true balanced
circuit topology in addition to balanced inputs. Most of the others just convert balanced inputs back to single-ended
circuitry. Preamps with single-ended circuitry use a phase
splitter to generate a balanced output. I have a rather limited grasp of electronics, so anybody in the peanut gallery, please feel free to correct me. Two good references
on balanced inputs/outputs are:
Stereophile Vol. 17, No. 11 (November 94)
94)
Stereophile Vol. 18, No. 12 (December 95)
believe that Krell, Mark Levinson, BAT, Aragon, Jeff Rowland, Pass, possibly Simaudio, Classe, have true balanced
circuit topology in addition to balanced inputs. Most of the others just convert balanced inputs back to single-ended
circuitry. Preamps with single-ended circuitry use a phase
splitter to generate a balanced output. I have a rather limited grasp of electronics, so anybody in the peanut gallery, please feel free to correct me. Two good references
on balanced inputs/outputs are:
Stereophile Vol. 17, No. 11 (November 94)
94)
Stereophile Vol. 18, No. 12 (December 95)