Best op-amp so far from Burson. The v6 classic replaced OPA627 in my CD-player. Now it sounds as I want it. Powerful and detailed low frequency, warm and pleasant midrange and silky smooth treble. Recommended! Combination of v6 classic and v6 vivid my Valab DAC. Sounds very much like v6 classic alone, but with a little brighter and vivid treble. Also recommended.