The Dynaco Tube Audio Forum

Dedicated to the restoration and preservation of all original Dynaco tube audio equipment - Customer support for Tubes4hifi VTA tube amp and preamp kits and all Dynakitparts.com products


    Average Predictied GZ37 Lifetime?

    LeGrace
    LeGrace

    Posts : 320
    Join date : 2016-08-07
    Location : Ontario, Canada

    Average Predictied GZ37 Lifetime? Empty Average Predictied GZ37 Lifetime?

    Post by LeGrace on Sun Feb 10, 2019 3:47 pm

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

    Posts : 1532
    Join date : 2013-04-01
    Location : Michigan USA

    Average Predictied GZ37 Lifetime? Empty Re: Average Predictied GZ37 Lifetime?

    Post by sKiZo on Sun Feb 10, 2019 5:24 pm

    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.

    Average Predictied GZ37 Lifetime? Tube-set-APR18
    bbqjoe
    bbqjoe

    Posts : 96
    Join date : 2018-12-03

    Average Predictied GZ37 Lifetime? Empty Re: Average Predictied GZ37 Lifetime?

    Post by bbqjoe on Sun Feb 10, 2019 10:46 pm

    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.

    Average Predictied GZ37 Lifetime? Tube-set-APR18

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

    Posts : 1532
    Join date : 2013-04-01
    Location : Michigan USA

    Average Predictied GZ37 Lifetime? Empty Re: Average Predictied GZ37 Lifetime?

    Post by sKiZo on Mon Feb 11, 2019 6:56 pm

    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.
    avatar
    Drummerboy2

    Posts : 8
    Join date : 2019-04-28

    Average Predictied GZ37 Lifetime? Empty Re: Average Predictied GZ37 Lifetime?

    Post by Drummerboy2 on Sun Apr 28, 2019 3:44 pm

    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.
    10-E-C
    10-E-C

    Posts : 257
    Join date : 2014-02-12
    Age : 65
    Location : upper east tn

    Average Predictied GZ37 Lifetime? Empty Re: Average Predictied GZ37 Lifetime?

    Post by 10-E-C on Wed May 01, 2019 8:01 pm

    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.
    avatar
    Drummerboy2

    Posts : 8
    Join date : 2019-04-28

    Average Predictied GZ37 Lifetime? Empty Re: Average Predictied GZ37 Lifetime?

    Post by Drummerboy2 on Sun Jul 07, 2019 9:21 pm

    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.


    GreggW
    GreggW

    Posts : 72
    Join date : 2015-07-15

    Average Predictied GZ37 Lifetime? Empty Re: Average Predictied GZ37 Lifetime?

    Post by GreggW on Sun Jul 07, 2019 11:13 pm

    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...
    deepee99
    deepee99

    Posts : 2231
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Average Predictied GZ37 Lifetime? Empty Re: Average Predictied GZ37 Lifetime?

    Post by deepee99 on Sun Jul 21, 2019 6:31 pm

    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.
    Dave_in_Va
    Dave_in_Va

    Posts : 334
    Join date : 2013-04-02

    Average Predictied GZ37 Lifetime? Empty Re: Average Predictied GZ37 Lifetime?

    Post by Dave_in_Va on Sun Jul 21, 2019 8:05 pm

    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.
    avatar
    nmchiefsfan

    Posts : 54
    Join date : 2012-03-21

    Average Predictied GZ37 Lifetime? Empty Re: Average Predictied GZ37 Lifetime?

    Post by nmchiefsfan on Mon Jul 22, 2019 10:43 am

    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.
    Tube Nube
    Tube Nube

    Posts : 690
    Join date : 2008-12-06
    Age : 56
    Location : Calgary, AB

    Average Predictied GZ37 Lifetime? Empty Re: Average Predictied GZ37 Lifetime?

    Post by Tube Nube on Tue Jul 23, 2019 8:45 am

    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.

    Sponsored content

    Average Predictied GZ37 Lifetime? Empty Re: Average Predictied GZ37 Lifetime?

    Post by Sponsored content


      Current date/time is Mon Sep 16, 2019 1:04 am