Different lengths of interconnects ??????

Have you ever tried using a pair of interconnects in different lengths to connect preamp and mono block amps? Can it cause one channel delay or any phase problems?

My Preamp is placed on left side behind my active ATC speakers, but I always use a pair of interconnects in same length between my preamp and the built-in power amp of my speakers.

Now I have a chance to buy pair of Valhalla XLR interconnects in different lengths, one 1.7m and another 3.5m, from another city. They are just about the right length from my preamp to left and right channel of my speakers, and price is good. I am not sure if it is OK to use interconnects in this way. Anyone have this experience?

Many thanks!