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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
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mars2k
12 posts
 

Ok so I asked Mr. Google and he said, according to the article link, that cryo treament can help certain things. Vacuum tubes is probably not one of them

Cryo takes materials down to at least -190 C.  No barns in the US go down that low. Cryo treating  actually realigns the crystaline structure of steel and other materials.  Untreated steel has  a variety of steel crystal configurations.  Cryo literaly squeezes everything down to one uniform, the most stable, crystaline configuration. This improves strength and electrical conduction. It is assumed that this happenes in other materials but the engineer did not go to deep into that.

Ok so  with a single material cold can be good, everything changes together, no worries. However....tubes are assemblages of several different parts made up of several different materials each with their own physical properties. All of these components are bonded together with various tolerences. If you freeze an assemblage like this everything freezes with differing rates and results. Now try to thaw it out....again with differing results. So this complicated assemblage now at operating temperature may not be bonded together the same way any more.  It is no longer really at the same spec as when manufactured. Makes sense to me!

This guy did offer some hope.  His idea was that after cryo only the strong survive.  Stuff that warms up and is no longer in spec fails relatively quickly so that only superior tubes live on.

I think that opens the door for another question though. What if the thing that cryo breaks is the thing that makes the tube sing?  Remember when the tornado swept up Dorothy's house?  The old bat was still flying.

Now you guys stop fighting😃

 

vinylvalet
895 posts
 

My experience with the Gold Lion reissues have been uniformly good. I have a number of their tube types but have not tried their GZ34. Thanks, based on some of the good commentary above, I'll give it a try.

IMHO and experience, the best place to purchase any Gold Lion tube is from Jim McShane. He always goes the extra yard in his pre-sorting and testing. For example he tests for low noise at no extra charge unlike most of the competition.

jjss49's avatar
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jjss49
6,612 posts
 

yep, old post here

i advise all who ask that when it comes to gz34/5ar4’s it is really best to stick with old stock uk/dutch ones, and then usa ones, even if one has to pay up for them

the old world ones are exceptionally well built and last a loooonnnnggggg time... and because when rectifiers fail, the failure can hurt the device it is powering, so replacing a blown rectifier is often not as simple as just plugging in a new one into the socket... playing with modern rectifier tubes with lower reliability has hidden costs that can sometimes be rather high

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artemus_5 OP
1,925 posts
 

@jjss49 

I have been  told this before and will heartily agree. The fact is that many things were built much better before built in  obsolescence became the byword for mfgs. However, the problem is the $150+ for the NOS tubes.The GL was $40. But I understand the problems it can cause.

At the time I was using a Bob Latino ST-70 which is hard on rectifier tubes. Also I was surprised at how much a rectifier tube could have on the amp itself. This was the shock to me..And it lasted longer than others  Anyway, I now have a NOS  Matsushita (Japanese Mullard). but the amp is a backup now. Great sounding amp.

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mars2k
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Hi guys, I have a fully modded Modwright Oppo UDP 20w with Modwrighr PS 9.0 psu. They shipped with Sovtek 5ar4  the first one blew within a week blowing a fuse in my power conditioner.  The second one blew 5 months later blowing the fuse in the psu.  I'm new to tube world so flying blind a lot.  Upon research I found some supliers with pointers on subbing out tubes and which models do what. audiotubes.com is the most comprehesive list of tubes and descriptions and comparisons. Thanks for the Jime McShane tip

The first substitute fo the 5ar4 was a Tung Sol gz34. which offered a significant improvement over Sovtek (Sovetek from the Russian root word meaning "is crap") . Picked up a NOS Mazda (phillips) 5r4gys which changed everything for the better. Wow!  Just seeing the new tube was a treat. It had an obvious look and feel of a quality object. Amazing what a good rectifier tube can do.

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