how to best a/b cables


Ok, I admit it: I have serious doubts about the claims of those who believe in cables. But I am willing to take their challenge - let my ears decide. So I went to a local dealer (who is probably reading this thread - Hi!!) and got some Transparent speaker cables and interconnects to audition. My setup: Linn LP12 turntable, Linn Linto phono stage, Linn Ikemi CDP, Plinius 8200 integrated, B&W N804 speakers and 10 year old Audioquest cables & inters (I believe they are the "Ruby" models.)

My question: my Linn Linto has dual outputs. Can I connect my old cables into one output and the Transparents into the other and then run them into two different inputs in the line stage pre and thereby get a good way to a/b the cables? My dealer says it is not a good way to get an a/b comparison because the two sets of cables will affect eachother and it will muddy the water. Does this make sense? If I hook one into the tape1 input and the other into the tape2 input and if I'm switched to tape1, then tape2 is an open circuit and should be completely inert and vice versa. Any comments?

PLEASE!!! I DO NOT WANT THIS TO BE ANOTHER DISCUSSION ABOUT WHETHER CABLE QUALITY AFFECTS SOUND QUALITY!!! JUST HELP THIS LOST SOUL TO FIND THE TRUTH!
gboren
If both the Linto and the line stage have selector switches, then it is an open circuit. If the Linto does not, and both output terminals are always hot, then the presence of the second set of cables presents a slight load at the Linto output, which is different for each cable set and can result in small differences in the total Linto output. You can test whether any of it is audible by listening to one pair of cables w/wo the other set plugged in.
As to the minor difference in pathway between two different sets of input posts or output posts which are switched on the inside of the box, I think you'd have to be very golden-eared to hear the difference (assuming good build quality), but the strict rules of A/B'ing say that you should use the same terminals. I suspect the cable differences will greatly exceed the minor differences from this source. After all, A/B switching boxes are built this way, though admittedly they should be built carefully.
I think your approach will work just fine--much better than switching cables in and out, which introduces a time delay that will be far more confounding than any minute increase in load from having a second set of cables attached.

As long as you're going to this trouble, get a friend to help you do the listening blind. He can switch back and forth between A and B (at your instruction, so you can listen to them for as long as you like). Then let him flip a coin to decide which is "X," and see if you can tell which it is. If you can't score 80% on a reasonable number of trials this way, you can be reasonably certain that the two cables are sonically indistinguishable.
Also be carefull as to 'when' you flip the switch. If a loud passage is coming up just as you switch, you might belive you heard a tonal shift. Its actually very hard to switch between small sements of music, but if you wait for a whole track you will have forgotten what you just heard.

One weay or another this will be educational for you. Your dealer sounds 'closed minded':).

steve
I find quick switches back and forth do not work for me. I like to listen to a long passage of music, then switch and replay with the other cables. It takes many switches back and forth to really get a good handle on the all the differences between the 2 cables. I miss things when it is a quick switch back and forth. We listen long, so you should compare long. The negative fatigue factor won't become apparent with a quick switch. Neither will the good musical toe-tapping factor.
I agree with Sugarbrie and will go one further to say that quick back-and-forth switching actually obscures sonic differences between cables (or components). But try it both ways and see for yourself.