5ar4 rectifier tube

NOS Mullard GZ34

Like most others I normally stick to the  Mullards in my 5ar4/Gz34 positions. They are reliable. I have bought a couple modern tube preamps that use 5ar4's for rectifiers. They both came with modern China made tubes. I would leave them in while "breaking-in" the device & both died within a month. I'm not exaggerating. The last one didn't make it a week & when I pulled it out pieces of the pins were gone. No sign of any remnants..it's like they just disintegrated to nothing. 

Even though mullards are tried & true I have experimented with a few modern 5ar4 rectifiers. One that has worked well for me is the Mesa Boogie low sag tube. When I pop them in my preamp the sound becomes lighter, airy, nice sound. Makes my mullards sound darker in comparison. I even ran one for a few months in a ST-70 power amp with no issues. My Dynaco will chew up lesser quality rectifiers. Killed a brand new JJ instantly. 

I've bought & used 2 Mesa's  over the last two years. They are both still strong.  That doesn't exactly prove they have great quality control on all their rectifiers but so far they have worked for me. 

I love the mullard big base on my Allnic phono stage.  Surprised me what a difference it made verses stock.  Great sound and reliability.  

Here's another tube vendor that I have not checked out yet (recently discovered them).

http://www.vacuumtubes.com/5ar4.html

DeKay

@dekay , I like that he specifies that some of the tubes he sells are used. . . .