The Shuguang Treasure CV181-Z Vacuum Tube
Dick Olsher (August 2021)
It’s not really a British-spec CV-181 but actually a premium 6SN7 in a fancy carbon-coated glass envelope and may be substituted in any circuit that uses a 6SN7. However, what is remarkable about it is its inherent tonal sweetness, image focus, and excellent dynamic linearity. In these respects, it proved to be superior to even my favorite 7AF7 and 7N7 near-equivalents. As of now it has assumed the mantle of my favorite 6SN7 type. And yes, I’ve listened to a host of vintage types. It’s easy to find on eBay, and buy direct from China/Hong Kong. As with most things in audio, performance is context specific, so there is no guarantee that your results will match mine. But in my opinion, you would be foolish to pass it up.