Kaitie makes an interesting point, although pointless. Cryoed tubes don't perform any better than other tubes, don't necessarily last longer, and the myth that extreme freezing and thawing of grid screens and tiny wires improves anything is sales propaganda that's not based on reality.
Impressions of the Re-issued Genalex Gold Lion U77/GZ34 Rectifier Tube
First some qualifications. I only have ears to judge. I have little knowledge of circuit design etc. But I have spent about 15 yrs putting a very good system together which I would be happy to show to anyone. I have also learned that synergy is the key to success in putting together the magic that we all are looking for. I am not totally new to tubes. But if my system sounds good, I generally leave it alone. Okay, so that's not completely accurate... I leave it alone longer than many others. My point is that I have not all the different GZ34 tubes. But I have some. I tried SS as recommended. (Weber Copper cap) It sounded awful to me and my wife.
My system is listed in my profile. The amp is a Bob Latino VTA ST-70 with all upgrades offered. Bob built the amp in "09. I didn't realized the importance of a good rectifier tube until I got the Genalex Gold Lion. I've had this in a little less than a week. First impression.....WOW!!. The attack of the plucked strings on SRV's "Tin Pan Alley" was fantastic. Extremely sharp. Plenty of air. I was spell bound. But I wasn't expecting what came next. the bass kicked in and was at least an octave or more deeper than it was the previous day when I listened to it with a different rectifier tube.(Sovtek) It hit me in the chest more than it has ever done. I have fought hard to get the adequate amount of bass in my room for years. The room is 5000 cu ft which is a lot to fill. So this is welcomed. If you have a bass heavy system it may not be your cup of tea unless you can tame it. AAMOF, I turned back my sub last night. I've never done that before.
At first I thought my new cartridge (Zyx 4D) may be playing a big part since it digs out more bass than my previous cartridge. Its been in the system about 6-8 weeks. However, putting on a CD showed the same tendencies as what I had heard on vinyl, though maybe not to the same extent.
I am very happy with the Genalex GL GZ34. The price is $40 which puts it at the top price for the re-issued GZ34's. I had a GL in the amp before which had a very short life span
https://forum.audiogon.com/discussions/genalex-gl-gz-34-rectifier-did-i-just-get-a-bad-one-five-mont...
However I suspect it may have been due to a weak tube being cryoed and used in a demanding amp. This one is not cryoed and was hand picked by Jim McShane. The sound is good enough that I would be willing to buy a new tube each year because the sound is that good. Certainly I hope that isn't the case. However, Jim (& I) believe that a good GZ34 should handle the ST-70, though that has been pointed out as the short coming of this amp. However, I got at least 3 yrs out of the original GZ34 tube. Maybe I'll get a good life from this one. Like the previous one, I will enjoy it while it lasts. Its a winner.
My system is listed in my profile. The amp is a Bob Latino VTA ST-70 with all upgrades offered. Bob built the amp in "09. I didn't realized the importance of a good rectifier tube until I got the Genalex Gold Lion. I've had this in a little less than a week. First impression.....WOW!!. The attack of the plucked strings on SRV's "Tin Pan Alley" was fantastic. Extremely sharp. Plenty of air. I was spell bound. But I wasn't expecting what came next. the bass kicked in and was at least an octave or more deeper than it was the previous day when I listened to it with a different rectifier tube.(Sovtek) It hit me in the chest more than it has ever done. I have fought hard to get the adequate amount of bass in my room for years. The room is 5000 cu ft which is a lot to fill. So this is welcomed. If you have a bass heavy system it may not be your cup of tea unless you can tame it. AAMOF, I turned back my sub last night. I've never done that before.
At first I thought my new cartridge (Zyx 4D) may be playing a big part since it digs out more bass than my previous cartridge. Its been in the system about 6-8 weeks. However, putting on a CD showed the same tendencies as what I had heard on vinyl, though maybe not to the same extent.
I am very happy with the Genalex GL GZ34. The price is $40 which puts it at the top price for the re-issued GZ34's. I had a GL in the amp before which had a very short life span
https://forum.audiogon.com/discussions/genalex-gl-gz-34-rectifier-did-i-just-get-a-bad-one-five-mont...
However I suspect it may have been due to a weak tube being cryoed and used in a demanding amp. This one is not cryoed and was hand picked by Jim McShane. The sound is good enough that I would be willing to buy a new tube each year because the sound is that good. Certainly I hope that isn't the case. However, Jim (& I) believe that a good GZ34 should handle the ST-70, though that has been pointed out as the short coming of this amp. However, I got at least 3 yrs out of the original GZ34 tube. Maybe I'll get a good life from this one. Like the previous one, I will enjoy it while it lasts. Its a winner.