My amps ONLY have balanced connections as they are fully balanced and do not provide for single-ended conversion. Prior to my current balanced preamp, I used several single-ended preamps. I also used Jensen input transformers to effect the conversion. Although my transformers were an outboard model requiring an additional very short IC cable, Jensen or Lundahl transformers are used by some manufacturers "inside" of amplifiers for the same reason. The transformers offer the added benefits of a ground break (they can correct hum problems) and I believe they also block DC. However, there are impedance matching issues requiring you to keep the IC cables short'ish and they may not work with amps having low input impedance....like 10-20K ohms.