5AR4 rectifier tubes - Chinese or Russian?

Your rectifier tube will have a marked effect on the overall sound of your unit. By going cheap there, you'll be ripping yourself off for a lot of music. If you went with a pair of NOS Mullards (GZ34/CV1377, from the Blackburn plant), they'd probably outlive your ownership of the unit, and would definitely improve the unit's presentation(compared to ANY new production tube).

I use the Japanese tubes which Kevin Deal carries.Two in my Prologue 8 CDP .And one in my SLP-05 Cary Pre amp power supply...Great bang for the buck..You won't be disappointed.

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).