5ar4 rectifier tube

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

I sort of remember Uncle Kevin saying (on his site) that Prima Luna had some special 5AR4s that they liked for the Prima Luna Prologue 8 CDP.  Are those the only rectifier tubes that they are saying to use with that preamp?  If I remember correctly (and it is quite possible that I don't) aren't those 5AR4s for the Prima Luna a bit taller than the average 5AR$?

First thing you need to do is realize that Uncle Kevin is a salesman, and a business owner. That doesnt mean that he is dishonest, which I dont beleive that he is, but he does steer his customers to what he has on hand. And that isn’t always your best option.

Since Uncle Kevin sells GL 5AR4s I kind of doubt that's why he is advising not to use it in that preamp.

https://upscaleaudio.com/products/gold-lion-u77-5ar4-new-production-rectifier?_pos=1&_psq=5ar4&_ss=e&_v=1.0

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.