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.
128x128artemus_5
For the record I had two ‘52 Sylvania Badboys and one ‘42 Tung Sol rectifier tube in my pure tube headphone amp. All were cryo’d by Cryopro. Great sound. Long life. I was one of the very first to employ a cryo lab on a regular basis and also one of the first to employ a humble home freezer for the same purpose. That was about 20 years ago. You’d probably be shocked if I told you what things I’ve had cryod or frozen over the years. Please, no angry emails 😡 demanding that the home freezer isn’t cold enough.
@viridian 
I haven't done the diode mod. Bob said I didn't really need it.  I got the Weber Copper cap SS rectifier. It stayed in about 1 1/2 hrs before I just couldn't stand it anymore. Terrible in my system
@jetter  +1 the Gold Lion KT77 was really a revelation for me. I was having some issues with tube failure so with my last quad paid a bit more for better quality at Upscale Audio. I've had that quad running 14 months now without a hiccup and I listen 6 or more hours per day. Highly recommend that tube to anyone!
The Mullard 5AR4 rectifier sounds best among what I’ve tried. Next up is JJ, but they’re incredibly fragile. So many Shuguang tubes excel, both sonically and in terms of reliability. While I’ve found their 5AR4 rugged, the sound falls a far bit back from the JJ, unfortunately. Sovtek tubes, as usual, sound BAD.

Glad to see you here, Marty, my old friend! Hope all is well
Deep freezing is an unnatural and frankly tawdry thing to do to your poor little tubes. I was warned against those years ago from people who've had them fail, so I avoid previously frozen tubes and only use fresh, un tainted tubes. Some do arrive in the mail kind of cold but I can't avoid that.  I have a JJ 5Y3 (came with my Dennis Had Fire Bottle amp) and didn't know it was fragile but I'll consider myself warned, and the large cool looking Shu Guang 234B seems to work OK (gets points for "best looking" rectifier tube often in tube beauty pageants, and I put a tiny "Miss China" sash on mine which also helps by damping microphonics a little), but so far the GL U77/U34 seems to sound best in this SEP amp. I'm going to try an old Mullard though…I mean…how can I not?