Shuguang Treasure Series CV-181Z ( 6SN7) SOLD

Selling a pair of the above near new 50th Year Anniversary Shuguang Treasure series CV 181-Z, 6SN7 equivalent. This treasure series tube is the best ever current production tube ever produced. Sonics rival the best of costly and hard to find NOS 6sn7s. Refer as below:


Shuguang is the oldest and largest
tube manufacturer in China, established in 1958 by engineers educated
and trained in the United States during the late 1930's and early
1940's. Today, Shuguang's vacuum tube production accounts for 40% of
the world's total tube output, either under their own brand "Shuguang",
or under various OEM brands. Generic
Shuguang tubes come in clear glass bottles. However, the Treasures
series have a carbon compound coating applied inside the tubes making
them appearing to be "black bottle" or "black glass". The first
Shuguang Treasures tubes were released in December of 2008, to
celebrate both Shuguang's 50th anniversary and to highlight a variety
of important technological advancements in their tube production, such
as:

• High
  Polymer Compound Carbon (HPCC) coating is for the first time used on
  vacuum tube production. Compared to traditional carbon spray
  technology, HPCC coating will allow greater concentration of electrons,
  enhance and maintain stability of the electron flow, maximize
  "secondary electron emission suppression" from the glass enclosure, in
  turn reduce effects of electron swirl which generates internal noises
  from the vacuum tube itself.
  
• "Super
  Alloy" technology is for the first time used in constructing vacuum
  tube. 'Super Alloy' technology was invented and first used in aviation,
  aerospace, military and other high-tech market segments. After 3 years
  of testing under extreme conditions, Shuguang has successfully adopted
  such technology in vacuum tube construction, to achieve directional
  solidification and single crystallization, greatly improving the
  ability of electron emission and electron current stability.
  
• Improved vacuum technology during production process, to further improve the signal background
  
• Unique triple mica insulating spacers and four independent supporting poles to all but eliminate microphonic effects
  
• Gold coated grid and gold coated pins, plus white ceramic base
  
• Key
  assembling processes are manually completed by a small number of senior
  technicians with 30+ years of experience. These tubes are truly
  handcrafted.
  
• An
  additional sixty part selection and matching processes are adopted to
  ensure premium quality tubes, compared to the Shuguang generic clear
  glass variety.
  

Perfectly matched pair used hardly over 40 hours, perfectly near new, asking for SOLD.