I am looking at getting some new speaker cables as I have a set of chord rumour 2s the longet run is about 3.5 metres .My amps are custom built tubed mono blocks, speakers are Dali Zensor 3s. I love the bass but the treble is a touch bright and from what I have read silver can do this on a cable, *please correct me if I am wrong*.
So I am looking for some new cables I am looking at the Van Damme range and just wondering what diameter would be the best?

I forgot to say I find the bright treble is when streaming my dac is a Beresford tc7530 it is fed with a Raspberry Pi3 that runs to thedac via a five metre toslink lead, all my interconnect`s are Klotz mc 5000 at present but I do have a few sets of other make interconnect’s, could that be the issue ??