Do balanced/symmetrical phono cables really exist?

Hi,

I play, or try to play, with a balanced Blue Amp 42 with symmetrical inputs so I need a symmetrical phono interlink to get the best result (playing with a non-balanced interlink would mean a loss of 6 dB gain). So I go look look for a symmetrical interlink. I mail a well known cable cooker in the Netherland, where I live, and ask him about his balanced phono interlinks. The answer I get is roughly as follows:

'to be honest, my symmetrical interlink isn't really symmetrical. It has the same construction as an RCA/ cinch cable. The only difference is that it has xlr-connectors.

At he moment I'm using a Kimber 1230 phono cable with xlr-connectors and I am pretty sure that this one is non-symmetrical as well, just xlr-connectors because I don't seem to get enough gain from my phono-pre.

What's your stand on this, do symmetrical phono interlinks exist or are we all being fooled bij the manufacturers?

Jos