Four EL34's arrived on my doorstep yesterday morning. Christmas came early this year.
Based on many people's comments on this thread, describing their experience of cryogenic tubes as a waste of money, clever advertising, and providing no measurable improvement over their stock tubes, I was simply hoping the CryoTone tubes were not that obviously inferior to the upgraded Psvane tubes I originally purchased with the amp (Willsenton R8).
I spent about 4 hours listening to them in my system yesterday and 5 hours today. I can say without any reservation this was money well spent.
The difference between the old tubes and the new cro'd tubes is not huge, not it's not small either. It was about 2 minutes in that I realized I was hearing something different. It took another 2 minutes to figure out what the difference was. I noticed textures were more vivid with more nuance. Further listening revealed improved micro details. Details that reside deep in the mix are now more articulate. At the extremes, small almost imperceptible "pop" sounds on electronic tracks, like static from old records take on more character. Some of these "pops" now render themselves as wet, or dry, some have bloom and decay where they used to come and go without adding much to the presentation. I guess what I'm saying is I'm hearing deeper into the music.
When comparing old gear to new gear, we often "listen harder" to the new gear because we are naturally biased and are listening so intently that we can't help but pick up on differences and interpret these differences as improvements. While that may be true I have listened to some of these tracks hundreds of times, if not thousands, and I'm 100% confident I've not heard what I'm hearing now.
I asked my wife, who's not a critical listener what she thinks and she said "the music sounds cleaner".
I hate to put a number to it, because that just doesn't do justice to the overall change to my system, and i's always going to be subjective. But what I'm enjoying now is at least a 10-12 percent more vivid and colorful presentation.
Not all cryogenic offerings are the same. Like a lot of tech in this hobby it's all about the alchemy, the synergy of small differences that make music more enjoyable.
To those that have reservations about measurable differences of cryogenic treated tubes, I recommend watching Decware''s video on CryoTone.
As to the manufacturer's claims about longer life I'd take that with a grain of salt.