Best currently available rectifier tubes for Mark 3 amps

Have a pair of recently "re-done" Mark 3 amps. Stock board with all nos carbon comp resistors Clarity Caps. SDS cap board to replace quad cap. Gold Lion reissue KT88s , RCA 6AN8 , teflon sockets. What is generally considered to be the best choice for rectifier tubes? I have a pair of Sovtek 5AR4/GZ34 , and a couple of boxes of NOS 5R4 , 5U4 tubes. Can't really afford to lose any power as I am trying to push a set of Magneplaners. Are the re-issue Mullard or Gold Lion tubes any good or should I skip lunch for a month ant find a set of vintage Mullard tubes ($$$$$) ?

I've heard good things about these little guys ...

http://www.nostubestore.com/2016/10/reflektor-54-gz32-gz33-5z4gt-ussr.html

stevenally wrote:Have a pair of recently "re-done" Mark 3 amps. Stock board with all nos carbon comp resistors Clarity Caps. SDS cap board to replace quad cap. Gold Lion reissue KT88s , RCA 6AN8 , teflon sockets. What is generally considered to be the best choice for rectifier tubes? I have a pair of Sovtek 5AR4/GZ34 , and a couple of boxes of NOS 5R4 , 5U4 tubes. Can't really afford to lose any power as I am trying to push a set of Magneplaners. Are the re-issue Mullard or Gold Lion tubes any good or should I skip lunch for a month ant find a set of vintage Mullard tubes ($$$$$) ?

Both the Genalex/Gold Lion U77/GZ34 and the Tung-Sol current production 5AR4/GZ34 are FAR better than any other current production rectifier I know of. The new Mullard may be as well but I have no experience with it. Be aware that a lot of the people who pass judgment on these new rectifiers have no experience with them so don't take everything you read as fact.

Here's the list of what I have used thus far on my M 125s: Genalex/Gold Lion U77/GZ34, PrimaLoona 5AR4 pulled from my Pre-Amp, was really surprised with this one, guess it's an expectation game...Chinese Shuguang...sorted before getting the PrimaLoonie tag, Mullard GZ33, and the copper Weber. To be totally honest, I think the Weber sounds the best, GZ33 a close second, and then the other 2 about the same. But, you have to really push them (crank it up..get the Led out..) all to hear a difference because at normal listening levels (when I'm not alone in the house!) they all sound about the same.

cci1492 wrote:Here's the list of what I have used thus far on my M 125s: Genalex/Gold Lion U77/GZ34, PrimaLoona 5AR4 pulled from my Pre-Amp, was really surprised with this one, guess it's an expectation game...Chinese Shuguang...sorted before getting the PrimaLoonie tag, Mullard GZ33, and the copper Weber. To be totally honest, I think the Weber sounds the best, GZ33 a close second, and then the other 2 about the same. But, you have to really push them (crank it up..get the Led out..) all to hear a difference because at normal listening levels (when I'm not alone in the house!) they all sound about the same.

The difference in voltage drops from one rectifier to the other can cause some sonic differences in the circuitry it powers. That voltage change is what accounts for the vast majority of tonal difference from rectifier to rectifier.

Has anyone here tried a Matsushita 5AR4/GZ34? I'm curious about this one, I bet they're at least as good as the reissues available today. There's a guy on eBay that's been selling them for a while just wondering if anyone here tried one on Bob's amps.

I have a good experience with the Sovtek 5AR4. I bought these rectifiers through a trusted source so I think that factors a lot. I have not used them in a Mark III, which I understand that stresses out the rectifier. My experience is limited only to the Dynaco ST70, and a few guitar amps (BFSR, Bassman 59, and SFPR). Again, my experience is limited, but me personally have no problem continuing to use the Sovtek 5AR4 as long as I can trust the seller. The price is just a marginal higher but well worth it. I should also note that I used the Ruby 5AR4 for the same application. I switched to the Sovtek more out of curiousity and not as a necessity. The Ruby performed just as good. But I did not put the same amount of hours on the tube as I have on the Sovtek.

I'm not sure what you mean by "best"...

I have been running the same pair of SOVTEK 5AR4 in my Mk IIIs for 4-5 years and these amps are my favorites. I think I paid $26 for the pair from guitarcenter.com. I always pre-rectify B+ with a pair of 1n4007 or 1n5408 so the 5AR4 is providing HV delay and voltage drop.

I have been running the same Tung-Sol 5AR4/GZ34 in my VTA120 for more than a year and probably have 1000+ hours on it. I am biased at 55mA/Tube + whatever the driver board uses so this tube takes a pretty good beating. I have yet to find one last this long. Well worth the extra $$ as I have never gotten more than a couple hundred hours out of the 20 dollar rectifiers I got at the guitar stores.

Replaced a Ruby, I think it was, 5AR4 with an NOS Mullard GZ 33 (or was it a 37?). An unmistakable improvement in the sound.

Tube Nube wrote:Replaced a Ruby, I think it was, 5AR4 with an NOS Mullard GZ 33 (or was it a 37?). An unmistakable improvement in the sound.

I've been running Mullard GZ 37s in a pair of M125s for almost 4 years now, played every night. No issues at all. You get what you pay for.

stevenally wrote:Have a pair of recently "re-done" Mark 3 amps. Stock board with all nos carbon comp resistors Clarity Caps. SDS cap board to replace quad cap. Gold Lion reissue KT88s , RCA 6AN8 , teflon sockets. What is generally considered to be the best choice for rectifier tubes? I have a pair of Sovtek 5AR4/GZ34 , and a couple of boxes of NOS 5R4 , 5U4 tubes. Can't really afford to lose any power as I am trying to push a set of Magneplaners. Are the re-issue Mullard or Gold Lion tubes any good or should I skip lunch for a month ant find a set of vintage Mullard tubes ($$$$$) ?

NOS Mullard GZ37 (old NATO stock) can be had from Watford Valves (UK) for 59,5 £ (excl. VAT 20%) which comes to 97 $ all-in except shipment.  This is quite some $$$ since you need 2.
BUT...… they will serve you for many, many years…..and….. you are assured to have the best tube rectifier.

I use one in a ST120.


For the record, I once bought a new issue Genalex GZ34 that did not work from day one. Maybe some bad luck…… I do love Genalex (KT88)