Metal-base and non metal-base 5AR4/GZ34?

Sonically, what's the difference between the metal-base and non metal-base 5AR4/GZ34 rectifier tubes, Philips/Amperex or Mullard? Especially as they perform in the Modwright 9.0 SE preamp?
Sonically, whats the difference between the Phillips and Mullard 5AR4/GZ34?
Anyone have any thoughts on the Mullard GZ34?

I think this one is the non-metal base one.
Metal base GZ-34's are really good and really expensive now.....

Hi Electroid

You weren't kidding about the metal base GZ34 tubes. Pricing started around $300 all the way up to $799 for a single tube. I'll pass on those metal base GZ34s. They cost more than the SET amp I got. Those Mullard GZ34 re-issues look like quite the bargain compared to those metal base GZ34 tubes I saw. Thanks for chiming in.
None of the re-issues will compare with a true Mullard(Blackburn Plant) GZ34, either in sonics or lifespan(metal base, or not).
If you listened to the real deal for decades, very unlikely you will find any "re-issue" worthy of listening to.
Wow Schubert and Rodman. Thanks for the feedback. I guess ignorance will be bliss for me. All I have is the Tung Sol Re-issue 5AR4 as the rectifier in my Tom McNally 6BQ5 SET amp and I'm happy with the sound. I won't ever know what I'm missing as I can't justify spending at least $400 on a metal base GZ34 and no one I know as one they can lend me. Whew am I relieved.
I suppose you missed the, "METAL BASE, or NOT," in my post. There are lots of bakelite base Mullard/Blackburns out there, for MUCH LESS than $400, any of which will outperform the reissues. Someone else just might happen to read this thread, that would appreciate the info. But, hey- as long as you're satisfied, HAPPY LISTENING! (
Hi Rodman,

Yes. I missed that part of your post regarding the Metal Base or Not. I feel stupid. Thank you for including the link with those affordable. They are more within my budget and I can score one now and use the Tung Sol as a back up.

Thanks again
The ones with the 'B' in the date code(ie: F32/B6H4), are from the Blackburn Plant. Personally; I found the double gettered type to be some of the most reliable and best sounding. A couple examples: ( or (
I just can tell that when I had Carry SLP-05 and replaced original rectifier with Philips Miniwatt GZ34/5AR4 metal base nos 1957 I could not believe the difference it made. Yes, it was expensive move, but with great result.
I just bought one of these for my Modwright SWL9.0 se
had to cut a hole in the cover to accomadate the size,but Im very happy with it. Got mine from a guy in Holland thru ebay for less $.