From: pfjw@aol.com   
      
   On Monday, November 9, 2015 at 1:17:20 PM UTC-5, Big Bad Bob wrote:   
   > On 11/02/15 03:39, Peter Wieck so wittily quipped:   
   > > The first one immediately smoked its filament. The second one, after about   
   20 minutes, melted into a mess - almost cartoon-like. Everything inside the   
   glass is tilted or rippled. The second one tested marginal before the melt, by   
   the way.    
   >    
   > > Friends don't let friends use Chinese Tubes.    
   >    
   > some are good, some are not, apparently.  I've heard that Ruby buys   
   > (some of) their tubes from China, then tests them before selling as   
   > 'Ruby'.  But that might be a rumor.   
   > need reputable sources, for sure.   
      
   Bob:    
      
   Here is the issue. I remember testing these tubes when they arrived (the amp   
   was well used), and they did rectify. Meaning, any local test will be 'good'   
   until it is not. Of course, this may be written about any tube, irrespective   
   of brand - but Chinese    
   tubes fall into their own category. Most reputable 5AR4 tubes fail fairly   
   gently - not spectacularly.    
      
   BUT, over an 8-year period, one apparently got gassy enough to pop the   
   filament, the other slagged. This was 8 years of NO USE.... not 8 years and   
   hundreds of hours - which would be understandable.   
      
   The going rate on a functional LK150 is up to/around $1,200 these days. I   
   would not risk such a device to someone else's tests. I am sure that Ruby   
   would replace a slagged tube, but would they replace a slagged power   
   transformer? Somehow, I do not think    
   so. And, yes, I do fuse the primary. I only hope the fuse is fast enough to   
   save things under dire conditions.    
      
   And, one of the reasons I am hesitant about re-branded tubes anyway unless I   
   am dead-sure of the provenance.    
      
   Peter Wieck   
   Melrose Park, PA    
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)