Don Sach's pre amp

@wig 

In my tests, the NOS tubes walked all over the CV 181-Z. If these tubes were as great as you say, the NOS 6SN7 market would dry up in a New York minute....

@ porscheracer

It's all circuit dependent and my NOS tubes smoked the CV-181Z in my Line Magnetic SET Integrated Amp. A good thing for us is that we do not have to go out and procure these treasures, just choose the ones that best represents our listening pleasure.

The CV-181Z are quite special if used in the right circuit and this has been talked about by some serious tubes critics over the years.

http://www.tnt-audio.com/accessories/shuguang_treasures_cv181_e.html

Wig

I tried them in a preamp and they didn't sound great.....I guess I will see as I have a paired ordered with my Don Sachs preamp.

Those tubes will sound good after 50 hours but will need 200+ hours to fully burn-in. Looking forward on receiving my D2 and Kootenay 120 KT 88 Amp.

Wig

I ordered a pair of the Shuguang Black Treasure CV181z tubes to try out with the DS-2. The DS-2 needs over 100 hours of burn-in time for the capacitors chosen for the build anyway....so I will use them for the burn-in and see how they sound compared to my current 6SN7 favorite, the Raytheon VT-231 with 8 copper rods and flat black plates.