5ar4 rectifier tube

You might look at Japanese production 5ar4 (Brent Jesse has them for $130/each).

Looks like he's out of them right now, @dekay .  I saw one on ebay for $100 not all that long ago, I think the seller was calling it a "Japanese Mullard," but after my last bad experience, I am personally not buying anymore tubes on ebay. 

Unless I am missing something, the only 5AR4s Uncle Kevin is showing in stock are the reissued GLs and Tung-Sols, which makes me think he is not saying to run the Prima Luna 5AR4 just so he can sell them.  I remember when he had "special" rectifier tubes (I think that they were 5AR4s) for that Prima Luna CDP he used to sell, he had those 5AR4s listed that were theoretically real good in that CDP, but his site was saying he would only sell him to people who had bought that CDP from him.

I use the tubestore "preferred" (Shuguang) 274b tubes in my Had Firebottle because they look so cool. They seem to work very well but mostly...hey...it's the look.

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.