Doug Schroeder Method, Double ic

Does multiple parallel transmission lines exist as a cable, of any kind? is there a a history in this area?

This is apparently a nordost cable, in this image.
 
The idea of parallel transmission lines is as old as the transmission line idea itself.
The trick is.... can it be made to work. It depends. On a lot of things.

One last point which I do not believe has been emphasized enough is that the longer the interconnects, the lower the characteristic impedance of the cable. Doubling a cable halves the impedance, and I have been avoiding longer cables (i.e. I have only worked with 1m interconnects to date) in doing the Schroeder Method, as I do not wish to encounter a situation where the output of the preamplifier (whether internal to a DAC or dedicated preamp) is not able to drive the amplifier, and potentially incur damage due to the characteristic impedance being too low. 

Those with more esoteric designs in DACS, i.e. NOS DACs, and preamps should exercise caution and understand the limitations of their gear, and accept the potential for damage if they proceed. At this point in time caution is still to be exercised as regards types of systems in which this can be done safely. 

Doug I have been thinking of puttting this thread, 2weeks ago, and Iam glad You and Tara’s chime in for more clarifications and information..I believe only few are aware about the double ic...

Is this similar to "Shotgun" with speaker cable?  If so, the improvement should be quite audible.

@stringreen

Audible is actually a bit of an understatement. Its easily comparable to an amp or pre-amp change sort of difference. In fact the level of improvement it brings to the table makes it a most effective cable nay-sayer-slayer.