AudioQuest CarbonPrices: $695 per 1.5m (Diamond); $159 per 1.5m (Carbon).

Website: www.audioquest.com

Doug said: While the degree of sonic improvement wasn’t large in absolute terms, it was just the sort of improvement that keeps audiophiles on the upgrade path. Kudos to the AudioQuest Carbon cable for bang-for-buck performance, and to AQ’s Diamond cable for cost-no-object performance. 

Read the Ultra Audio review.

The gist: We know, it makes no sense.