Recently, I upgraded an Anaconda SPDIF coax to a Sigma SPDIF coax from my N10 to the DAC. Very impressed is an understatement. (tho' I do fret why I didn't buy the Sigma XLR digital, but...)
So, I saw a great price on a lightly used set of Sigma RCA interconnects and I bought the single pair they had.
I replaced the Anaconda ICs from the DAC to the ET5 pre with the Sigma ICs. Wow. Who knew there was so much music in there! Performance jumped quite a few notches...more detail, sound more independent from the speakers, each instrument more distinct, no harshness at all, bass has improved tone and detail....
The very next day I bought a second pair of Sigma RCAs to run from my pre to my amp. They arrive next week along with a new Sigma PC for my DAC.
I had been quite happy with the Anacondas until I heard a few Sigmas in my system. Luckily, I have a second system for the hand-me-downs so I can continue to enjoy the Anacondas in the office.
As folks have said many times, don't try unless you're willing to buy. (I will not try Sigma SCs, I will not try Sigma SCs...
)
Expensive yes, but they are that good...replacing just the SPDIF and RCA IC was easily as significant as my last component upgrade (and better in some ways) in improving the sound. And another IC & PC arrive next week!
Highly, highly recommended.