Importance of matching 5U4G rectifier tubes.

I've never heard of matched rectifier tubes. As there's no amplification in a rectifier,  there's nothing to match that would cause an issue.

@noromance +1 You are correct!

I don’t know about matching rectifiers, I’ve never had more than a single one is any unit I owned or heard, but I’ll share this:

my friend had Kara make him a preamp

http://www.dehavillandhifi.com/UltraVerve-Preamplifier.htm

She included new tubes, and some alternate used tubes, including a Rectifier.

We listened here, heard subtle changes, then we were both quite surprised by how much the sound changed with the alternate rectifier. I had no idea, both tested ok on both my tube testers.  

Congratulations on getting the WA5. I have one as well. This was the most significant upgrade of my headphone system of all time. Literally jaw dropping (after upgrading the 300B tubes).

First the rectifier tubes are not as important to sound. But might be important to the longevity of the tubes. I would send it in to Ray and ask to buy a matched tube. 

Also, I HIGHLY recommend Takatsuki 300B tubes for that headphone amp. I know they are expensive... but worth every penny... And their typical life is in tens of thousands of hours, These tubes are unreal... especially in this amp. You can see my headphone system under my userID. 

Thanks everyone for the information. Since my original 5U4G is basically new,  I've just ordered another one will use both in my WA5. 

@elliottbnewcombjr , interesting that you noticed a difference in sound from the rectifier. I've read mixed reactions how the  rectifiers affect the sound. I wonder how much the transformers in different ams/preamps affects the rectifier tube making  a difference in sound?

@ghdprentice , thank you. I am fortunate and happy to be able to have it. One of the things I like about it is the versatility with impedance and power options.  The Auris Nirvana was my other choice. I sold my LTA Z10i which has been my favorite headphone amp to date.  I haven't spent a lot of time with it yet, so reserving final thoughts until I listen more and upgrade tubes. Besides the Ray rectifier tubes, I have just installed Ray Reserve 6SN7's for drivers. Thank you for the Takatsuki recommendation. After research and knowing the type of  music I listen to most,  I think I'm going to find either  the Audio Note  4300e or the EML 300b. The Takatsuki and the Elrog are a little more than I want to spend right now.