Average Predictied GZ37 Lifetime?

These are big tubes, are they like power tubes where 3000 hours is a reasonable assumption?

I don't count hours here, but I can say I got several years of hard rockin' on the current one. That's also driving a quad of KT120's most of that time. Also picked up on a spare while I had the chance before the price bloomed a bit back.

sKiZo wrote:I don't count hours here, but I can say I got several years of hard rockin' on the current one. That's also driving a quad of KT120's most of that time. Also picked up on a spare while I had the chance before the price bloomed a bit back.

I'm still highly impressed with your work on this amplifier!

More importantly ... so am I !! ;-}

I've also got a Mullard GZ34 here that racked up quite a few miles before I scored the GZ37. At the same time, I ended up smoking a couple Chinese tubes fairly quickly. Lot depends on how well built (or overbuilt?) the tube is.

sKiZo wrote:More importantly ... so am I !!    ;-}

I've also got a Mullard GZ34 here that racked up quite a few miles before I scored the GZ37. At the same time, I ended up smoking a couple Chinese tubes fairly quickly. Lot depends on how well built (or overbuilt?) the tube is.

My Mullard GZ37 is still going strong, about a year of playing hours on it now after not using the VTA-120 for a while. I checked the bias the other day and the bias is still at .50Vdc just like I set it back when I first installed the GZ37. I wanted to say Thank You again SkiZo for that recommendation.

Drummerboy2 wrote:

sKiZo wrote:More importantly ... so am I !!    ;-}

I've also got a Mullard GZ34 here that racked up quite a few miles before I scored the GZ37. At the same time, I ended up smoking a couple Chinese tubes fairly quickly. Lot depends on how well built (or overbuilt?) the tube is.

My Mullard GZ37 is still going strong, about a year of playing hours on it now after not using the VTA-120 for a while. I checked the bias the other day and the bias is still at .50Vdc just like I set it back when I first installed the GZ37. I wanted to say Thank You again SkiZo for that recommendation.

My GZ37s have been in my M125s for 4 years and they are played a lot. you get what you pay for.

10-E-C wrote:

Drummerboy2 wrote:

sKiZo wrote:More importantly ... so am I !!    ;-}

I've also got a Mullard GZ34 here that racked up quite a few miles before I scored the GZ37. At the same time, I ended up smoking a couple Chinese tubes fairly quickly. Lot depends on how well built (or overbuilt?) the tube is.

My Mullard GZ37 is still going strong, about a year of playing hours on it now after not using the VTA-120 for a while. I checked the bias the other day and the bias is still at .50Vdc just like I set it back when I first installed the GZ37. I wanted to say Thank You again SkiZo for that recommendation.

My GZ37s have been in my M125s for 4 years and they are played a lot. you get what you pay for.

Yes you do! I have been happy with this GZ37 and got a lot of crap over on the AA for using one in my amp when I ask for help about my amp making popping noise on power up. Others were saying that it was not the right rectifier for my amp even tho I had told them it has been used for a long time with no other problems, finally I quoted what Bob wrote about the GZ37 being safe to use in the VTA-120. I appreciated their help but some just harped on the GZ37. Well it turned out to be the driver tube which may have gone bad due to the sockets needing tightening and cleaning. My amp has been running for two months now without any more issues and I'm still using the GZ37. My Biasing is still holding strong and I check it every two weeks since I use this amp almost every day for about 4-5 hours. Very Nice rectifier! I do have a Weber WZ68 rectifier for the amp just in case I do want to really crank it up.

If GZ37s weren't so expensive, I'd have a few. I've been running the same 5V3A since October '15. No way does it have the cool factor of the GZ37, but it works. I had a WZ68 and gave it away...

I have quite a stash of Mullard GZ-33s and -37s; bought them just before NOS went through the roof. I use the -37 in my ST-70 and the -33 on my ST-120. Dunno why; I've never had to replace the original GZ-33, even after a spectacular red-plating incident. And those big Mullards are as studly as they are sturdy: I even have a socket-saver under each so they absolutely lord over all they rectify.

If guitar amps are anything to go by and the Mullard GZ 33 and GZ 37 are anything like the Mullard GZ 34, it wouldn't surprise me to see them last 40 or 50 years.

I have been running a Tung-Sol 5AR5 that I purchased from Mr. Jim McShane 3 years ago. A rough estimate is 700+ hours on it. It is in a Latino St-120 with KT-120 tubes biased at 55mA each. I keep waiting for it to fail when the TDR board turns on the high voltage! (hopefully not jinxing it now). I think I paid 35 bucks for it.

deepee99 wrote:I have quite a stash of Mullard GZ-33s and -37s; bought them just before NOS went through the roof. I use the -37 in my ST-70 and the -33 on my ST-120. Dunno why; I've never had to replace the original GZ-33, even after a spectacular red-plating incident. And those big Mullards are as studly as they are sturdy: I even have a socket-saver under each so they absolutely lord over all they rectify.

“Let there be rectification” sayeth the Lord of Mullard. And his sweet soul sounds have been stirring my soul, discernibly better than the Ruby 5AR4, for a couple of years now.