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Genalex GL GZ-34 Rectifier...Did I just get a bad one? Five months seems

like a terribly short lifespan. I bought it in May and spent the extra money to get a "good" tube. It sounded good while it lived. But it went in a fiery inferno last weekend.  Fortunately it only took out a fuse.

It was running in a Bob Latino VTA ST-70 Dynaco amp. It's a great amp but runs the rectifier a bit hard from my understanding. However the original tube lasted at least 3-4 yrs IIRC. I tried a SS rectifier. YUK!! I put the tube (a spare Sovtek) back in place I've had good luck with the KT-66 Genalex GL's and they have a good reputation (I think). Is this just the luck of the draw. IOW, even a new tube can have a short life span? Or is this odd? Is there any way to avoid it? I'd buy another Gennalex GL if it will last. But I can buy 2 Sovteks for the price of one GL. Sovtek sounds good too.

FWIW, The tube that failed was cryo treated. Could that make a difference in a rectifier tube? As always, Thanks for your help.
128x128artemus_5
hifiman5's avatar
hifiman5
1,832 posts
 
@artemus_5 You didn’t mention where you sourced your Gold Lion from. I have had great success with Gold Lions sourced from Cryoset. I have been using their 12AU7’s for many years with great results and long life. I just recently replaced the 5AR4 rectifier tube in my SACD player power supply with a Gold Lion GZ34 from Cryoset. I also added a Herbie’s Audio Lab HAL-O III-30 Stabilizer to the GL. The sound is a bit warmer than what I was getting with the Sovtek and the soundstage has opened up a bit. All is good. If you haven’t tried Cryoset, you may at least want to give Ron Sheldon a call and discuss your situation with him.

Good luck!
jond's avatar
jond
5,923 posts
 
I believe the OP is talking about a current production Genalex since he mentions the tube being cryoed. As others have stated sometimes a tube is just bad old or new.  A rectifier generally should last a fairly long time. I had a NOS Philco 5ar4 go out with a flash and a bang a few years ago and at the suggestion of my dealer got a variac. For around $100 off eBay it has a 2k transformer and ramps the voltage up slowly. I’ve used it ever since haven’t lost a rectifier.Look for good deals on rectifier tubes on here, I picked up some NOS RCA 5ar4 60s era tubes from member aztubes. They sound fantastic and have been perfectly reliable.
artemus_5's avatar
artemus_5 OP
1,992 posts
 
Trelja
It was not a NOS but a new production Genalex GL.

Hifiman

I bought the GL with a quad of 6p3se/6n3ce from Cryoset. First time I’ve dealt with him but his service was outstanding. And he was very friendly. I didn’t name the vendor because I didn’t believe it to be his fault and didn’t want to give a false impression.
I have some thoughts about it and conclude that cryo treatment is not a good thing for the rectifier tube which is under more stress than the other tubes. There are articles which address this issue of super cooling a fragile tube made of different materials which expand and contract at a different rate. I read this after I posted.
hifiman5's avatar
hifiman5
1,832 posts
 
@artemus_5  Good point about the thermal issues with a hot running rectifier.  I leave my system on 24/7 so there is no thermal shock experienced by the tube.
artemus_5's avatar
artemus_5 OP
1,992 posts
 
Hifiman
Do you leaveyour amp in standby mode? IOW, How do you keep from running through tubes quickly?

Jond

The Variac is an interesting idea. Thanks
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