5AR4 rectifier tubes - Chinese or Russian?

I agree with Rodman99999 .

I have Mullard 5AR4/GZ34 Tubes [ Amperex - Holland are nice also and fall into the same Class ] that were well used when I bought them and have been in service for 7+ years in my System . They still Test as New and will probably outlast me .

If you can find NOS - NIB great , but you will pay big time for them . I suggest buying New Testing Used for $25-$35 . They DO have a better sound than the New Production Tubes that I have tried and have a much longer life-span .

A third knod to Mullard / Blackburn NOS. Expensive, but worth it and will likely last long. Buy from a reputable seller, like Upscale, Vintage or The Tube Store. A rebranded Mullard should be $75-85/tube last time I checked and could be branded as Amperex, RCA, GE or some other companies that had Mullard make their tubes. Mullard branded tubes (labeled "Mullard") will run more expensive so I'd look for the rebranded ones from a reliable seller. Same tube with a different label. Best versions of the 5AR4 are actually metal-based versions but those will cost your first-born, and I'm not sure are worth the added premium (I guess that depends on how much you love your child). If you'd prefer to hang onto your heir apparent you could seek out an NOS 22S22C substitute, for which your soul may be adequate payment. Worth it for the extra bottom end resolution and bragging rights.

If the Mullards are beyond what you'd like to spend, you might look into those Japanese Mullard copies. I've no personal experience with them, but if Kevin gives them his endorsement- that speaks volumes.(http://www.upscaleaudio.com/Japanese-5AR4_p_75.html) I DO know that the Japanese are positively anal when it comes to quality control and consistancy in manufacturing practices(diametrically opposed to the chinese mindset). You might contact him, and ask his opinion with regard to their use in your unit. He's always happy to assist a fellow music lover and tubeophile. It's a shame he doesn't have any Mullard GZ34's(which would still be my #1 recommendation).

About 11 years ago I bought a boutique guitar amp--a Top Hat Club Deluxe, which is all tube PTP wired, and also used a GZ34/5AR4 rectifier. I decided to replace the Sovtek tubes and Chinese rectifier with new old stock US and European tubes. The NOS preamp and power amp tubes were affordable enough at the time (if you knew where to look), but all the US and European NOS rectifiers were well over $100. I decided to compromise and got an RCA-Japan 5AR4 for $25. I'm glad I did. Word from the vintage guitar gear enthusiasts was that a poorly made rectifier tube could kill your amp. My RCA-Japan has been exemplary. Its price sits on the low side between a Chinese tube and a US-Euro NOS, but its dependability is like the US-Euro NOS.

So to me, the Japanese tubes are worth the extra money over a Chinese tube for the peace of mind.

Buy a metal base gz34 and never look back.