I have a CD issued by high-end solid-state amplifier company Ayer Acoustics titled "Irrational, but Efficacious System Enhancement Disc". My dealer, now out of business(owner died), let me borrow it. Never returned it. It has white, pink, and 3 brown noise tracks. Brown noise is ideal for breaking in everything that needs breaking in: Cables, speakers, amps, DAC’s, etc. The last track is a 5 minute glide track that goes from 5Hz to 20kHz. Played at a moderate level, it makes your system sound better. It’s available at Ayre’s website. I’ve been using this disc for 20 years. I don't consider AC filtering components tweaks. Not anymore. Every reviewer in The Absolute Sound and Stereophile lists AC components in their gear. I have a long discontinued PS Audio Duet passive filtering device. Their AC Regenerators are bad ass, but Michael Fremer, a reviewer I respect, told me "I'm not plugged a power amp into a power amp." Audioquest has a good article on AC treatment. Of course the writer pushes his own design.
