Why 6H30 Tubes?

Curious why so many manufacturers have gone with the Russian 6H30 tubes in their designs?
(http://www.balanced.com/) Click on, "The 6H30 Tube - One Designer's Perspective" for some info. That was dated before the tube was readily available in the market. I still personally prefer the upper crust of the NOS 6922 family(ie: Siemens CCa or E188CC). They just sound more natural to me.
My 2 cents - I have owned several products with 6h30s during the last years:

1. They last between 5000-10000 hours
2. They are rugged and reliable
3. The 6h30 has low plate resistance
4. Good quality ones are easily available and inexpensive.
I'll add my 2 cents worth also. I have owned many, many preamps, (and still own 2 phono stages) that use the 6DJ8/6922 tubes and enjoy them very much, but on the line stage side of the preamp, I really like what the 6H30 tube does.

The 6H30 still sounds like a tube, but has better bass control, more detail, (without sounding sterile or cold). It also provides a cleaner, crisper soundstage without being too solid state sounding.

I concure that they are almost bullet proof and last a VERY long time. Seems like preamps that use 6H30 tubes only use a few, unlike some others that use upwards of 10 or more tubes.
Mmm, there are 8 x 6h30 tubes in my BAT. For an amp without a phono stage that seems way like a lot.

Metralla, I didn't say ALL or EVERY preamp. Sorry I stand corrected.
From SoundStage! review of C/J Act 2

"Conrad-Johnson’s adoption of the 6N30P for use in the ACT2 appears to signal the company's long-term acceptance of this tube as a replacement for the 6922. The 6N30P is a high-current/low-voltage device whose very low plate resistance requires no cathode follower. It makes for a nearly ideal preamp tube. Whereas the ART used five 6922s per channel (ten triode sections in composite), the ACT2 only needs two 6N30Ps (four sections) per channel to yield its 20.5dB of gain. Indeed, Lew Johnson commented to me, "The 6N30P has some unique advantages -- mainly exceptionally high transconductance, allowing it to substitute for three to four of the 6922s. However, it has commensurately high current demands on main B+ and heater supplies, so costs are roughly comparable to a unit using three to four 6922s for each 6N30P."
>However, it has commensurately high current demands on main
>B+ and heater supplies, so costs are roughly comparable to
>a unit using three to four 6922s for each 6N30P.
Shure, and using 4 tubes in the ACT2 compared to the 10 of the ART increased reliability and tube maintenance.
I owned (and loved) an ART series 2. But sometimes one of the 6922 intermittently became noisy and the only solution was discarding all the tubes or spending one week listening for noise, not to the music!
It's a no-brainer really, and one has to get really creative to attempt to support any argument against this tube's suitability for high single stage pre-amp gain. High gain/low impedance, high reliability and low noise. We all know that some guys will find fault with anything but come-on! What's not to like. And to put the cherry on the top of this fine confection, unlike many of the typical Russian small signal tubes such as the ubiquitous 6922, it actually sounds pretty darn good instead of leaving us feeling like we were left outside in the soulless Siberian Winter with the typical Sovtek tube signature sound,- hard, cold, uninviting and analytical. Why 6H30 tubes? Because it is the right tool for the job and fortunately we just happened to find it lying in the bottom of our toolbox! DEVIN