The Dynaco Tube Audio Forum

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


    Weber WZ68 now NOT recommended on Weber website!

    Share

    Bob Latino
    Admin

    Posts : 2415
    Join date : 2008-11-26
    Location : Massachusetts

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by Bob Latino on Tue Jun 02, 2015 11:57 am

    deepee99 wrote:I have two Webers (WZ68s) and two Mullards (GZ 33s), and two M-125 amps. I am going for Holger's 2 holer rectifiers mod.
    Question is, can a Weber and a Mullard live next door to each other, and how would this mess up the bias?
    The obvious answer would be to put both Webers into one of the amps, and the Mullards into the other. But I am looking for the un-obvious. Not wanting to wreck things.


    The B+ will be higher in the amp with the Weber's and, as such, that amp will also have a different bias point than the other amp with the GZ33's. I don't think that the amps will sound any different ...

    Bob

    deepee99

    Posts : 1337
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by deepee99 on Tue Jun 02, 2015 12:02 pm

    Bob, maybe I misstated my question. Could I put a Mullard tube and a Weber side-by-each on the same amp?

    Bob Latino
    Admin

    Posts : 2415
    Join date : 2008-11-26
    Location : Massachusetts

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by Bob Latino on Tue Jun 02, 2015 12:18 pm

    deepee99 wrote:Bob, maybe I misstated my question. Could I put a Mullard tube and a Weber side-by-each on the same amp?

    Hi David,

    I don't know if that would work out well ? Each rectifier has different characteristics that may or may not work well together ? Personally, I don't thing that using two somewhat dissimilar rectifiers in the same amp is a good idea ..

    Bob

    deepee99

    Posts : 1337
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by deepee99 on Tue Jun 02, 2015 12:41 pm

    Bob Latino wrote:
    deepee99 wrote:Bob, maybe I misstated my question. Could I put a Mullard tube and a Weber side-by-each on the same amp?

    Hi David,

    I don't know if that would work out well ? Each rectifier has different characteristics that may or may not work well together ? Personally, I don't thing that using two somewhat dissimilar rectifiers in the same amp is a good idea ..

    Bob

    Bob, I would concur. Let's see if sKiZo has some drama on this matter.

    Kentley

    Posts : 335
    Join date : 2015-03-06
    Age : 64
    Location : Worcester, MA

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by Kentley on Sun Jun 07, 2015 8:33 pm

    An update from the Wilds of Worcester: I received a replacement Weber WZ68 at no cost from the manufacturer recently. It has been operating perfectly for three days of moderate use. I did make one change to my rig - I placed a small "whisperfan" six inches from the front left corner of my ST-120 facing diagonally so that the rectifier area could receive maximum cooling. It seems to be just what the doctor ordered.
    So - heat is apparently the gremlin here.
    I believe this approach is a sound one for the power trannie and output tube heat goblins as well, not that these have been a problem.
    A heckuva lot easier than the arcane mods suggested by some. Those are great ideas for someone with the toolage and patience to perform them. That ain't me.

    tajanes

    Posts : 12
    Join date : 2015-02-07
    Location : Chicago

    Weber WS1 for hi-fi vs WZ34

    Post by tajanes on Mon Jun 08, 2015 4:41 pm

    note: I have a WZ34 in my st-120, no pbs yet,
    interesting however the Weber web page now suggests using their WS1 for hi-fi use
    http://www.tedweber.com/ws1


    pedrocols

    Posts : 64
    Join date : 2014-11-24
    Location : Western MA

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by pedrocols on Mon Jun 08, 2015 7:37 pm

    So who is going to be the guinea pig?

    skriefal

    Posts : 118
    Join date : 2011-09-20
    Location : Utah, USA

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by skriefal on Mon Jun 08, 2015 7:55 pm

    I have a WS1 here if anyone would like to try it. Was going to use it with my ST-120 but never got around to doing much with it. Of course it does lack the WZ68's current limiting resistors...

    deepee99

    Posts : 1337
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by deepee99 on Mon Jun 08, 2015 8:01 pm

    Don't do it. Don't do it. Don't do it.
    UNLESS you've got one of Dr. Latino's slow-start boards. Otherwise, the minute you hit the power switch, all the volts in the world will slam into your stuff. The WS1 is a fine piece of gear, but it and the downstream parts need to date a bit before jumping into the sack together. Learned that in old Collins S-line days when we were all jumping into this new solid-state stuff, and losing those big rectifier tubes was a smart thing to do and saved $50 a month on the light bill. Output tubes need a little seduction before lighting their cigarettes.

    10-E-C

    Posts : 87
    Join date : 2014-02-12
    Age : 63
    Location : upper east tn

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by 10-E-C on Mon Jun 08, 2015 8:34 pm

    I built my M-125s the last of Dec 2014 with the WZ68 as the rectifier. Even tho I never had any problems with them I replaced them with Mullards GZ37s which I had talked out of from a friend of mine (plus a few bucks). When removing the WZ68s the outer casing started to separate from the base. Looks like the bonding agent was weaken by the heat. Since I have the case off of the WZ68s I'll make vent holes and keep them as backups.

    deepee99

    Posts : 1337
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by deepee99 on Mon Jun 08, 2015 8:40 pm

    Yeah, they're not as tightly put together because there's need required for a vacuum. You can pull apart a KT-88 almost as easily, but larger issues come into play. It's fun to watch somebody else's house burn down . . .
    Regarding all things tubes, just keep a fire extinguisher handy. As my source and friend for all tubes NOS is kind enough to remind me, "Don't ever turn your back on the sumbitches."

    tajanes

    Posts : 12
    Join date : 2015-02-07
    Location : Chicago

    venting a Weber WZ34

    Post by tajanes on Fri Jun 12, 2015 3:53 pm

    So, sounds like putting a slot or two at the bottom and top to provide ventilation is a no brainer, but how do you dismantle the Weber Copper Caps without destroying the unit? Are there small tabs / screws along the outside bottom edge (beneath the blue Weber label) or do you just 'work' the bottom off from the copper cap?

    thanks

    deepee99

    Posts : 1337
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by deepee99 on Fri Jun 12, 2015 4:40 pm

    tajanes wrote:So, sounds like putting a slot or two at the bottom and top to provide ventilation is a no brainer,  but how do you dismantle the Weber Copper Caps without destroying the unit?  Are there small tabs / screws along the outside bottom edge (beneath the blue Weber label) or do you just 'work' the bottom off from the copper cap?

    thanks

    Tmadden on this board is the expert on rehabbing your Webers. I think it's a straight pull but ask Troy first.
    Again, you're not preserving a vacuum but I think some hard twisting might dislodge the pins from the guts.
    A little venting (pardon the pun) seems to do the trick for these guys. They work splendidly with some air running through them, at least as long as high-dollar tubes.
    Again, I would consult tmadden for definitive advice. Doggone good pre-amp builder, too.

    skriefal

    Posts : 118
    Join date : 2011-09-20
    Location : Utah, USA

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by skriefal on Fri Jun 12, 2015 5:50 pm

    I was told that it's quite difficult to remove the copper "cap" from the base on newer WZ68s. Something about the type of glue that Weber is using now.

    mazeeff

    Posts : 122
    Join date : 2014-01-06
    Age : 61
    Location : Grand Rapids, Michigan, USA

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by mazeeff on Wed Sep 16, 2015 8:08 pm

    tajanes wrote:note: I have a WZ34 in my st-120, no pbs yet,
    interesting however the Weber web page now suggests using their WS1 for hi-fi use
    http://www.tedweber.com/ws1


    I went ahead and ordered a Weber WS1, and put it in my newly acquired Dynakit/VTA ST-70. It works great, and really tightened up the bass. It also runs very cool, at 109f, due to the lack of sag resisters. I had already been running a double diode full wave rectification on my 1967 ST-70, with no ill effects for many years, via a SDS Labs Cap Board. The WS1 boosted my B+ considerably, but I was able to rebias without issue. I know that a lot of people are concerned with running SS rectification without sag or delay. For me, it seems to work fine!

    Mike

    sKiZo

    Posts : 1312
    Join date : 2013-04-01
    Location : Michigan USA

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by sKiZo on Wed Sep 16, 2015 9:18 pm

    Worth repeating, you can get a bit of delay by installing a CL90 thermistor on the AC line.



    (I've since moved the blue wire UNDER the thermistor. Heat rises, and they get HOT. I also got fancy with the three tab ... not really necessary, but does keep things tidy.)

    That gives you a soft start. Trade off is, they never open up completely, so you DO lose a bit of B+, but that doesn't sound like it'd be an issue with the WS1, and it can be real handy if you're wall supply runs high like many do.

    I've used a bucker to drop the line level to around 117vac AND had the thermistor in place and still made it into the recommended B+ range ... granted, the low side, but close enough for a(n ex) government worker ...  without the bucker, I dead center.

    PS ... why a CL90? Larger surface area and better heat dissipation. A CL80 has a higher current rating, but I've never ever had a problem with the CL90, even with ham gear.

    Guest
    Guest

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by Guest on Wed Sep 16, 2015 9:25 pm

    mazeeff wrote:
    tajanes wrote:note: I have a WZ34 in my st-120, no pbs yet,
    interesting however the Weber web page now suggests using their WS1 for hi-fi use
    http://www.tedweber.com/ws1


    I went ahead and ordered a Weber WS1, and put it in my newly acquired Dynakit/VTA ST-70. It works great, and really tightened up the bass. It also runs very cool, at 109f, due to the lack of sag resisters. I had already been running a double diode full wave rectification on my 1967 ST-70, with no ill effects for many years, via a SDS Labs Cap Board. The WS1 boosted my B+ considerably, but I was able to rebias without issue. I know that a lot of people are concerned with running SS rectification without sag or delay. For me, it seems to work fine!

    Mike

    the concern about running a SS rectifier without some time delay for B+ in a tube amp is quite valid. It may not show any immediate signs, in fact, it may well be fine for a long time, but hitting tubes, especially cold tubes, with a hefty B+ is known to 'wear' tube down and a real possibility of shortening their life span.
    As well, in an amp thats been running for a while and you get one of those 'short' power failures, this can really cause havoc when hitting the power tubes with all the amp has got once power comes back up in a few seconds. If you do not have one of those manual reset GFCI's and no time delay for the B+, it can cause some expensive damage. At least, with a delayed B+ through a start up timer, this will lessen the chance of causing damage once power comes back up a few seconds after you lost it.

    Kentley

    Posts : 335
    Join date : 2015-03-06
    Age : 64
    Location : Worcester, MA

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by Kentley on Wed Sep 16, 2015 9:48 pm

    Well, I'm glad that someone had the courage to try the Weber WS1. Now I can go ahead and order one as a back-up to my cherished Mullard GZ37. Thanks, all. BTW I am running the VTA ST-120 WITH delay installed so I should have no problems.

    mazeeff

    Posts : 122
    Join date : 2014-01-06
    Age : 61
    Location : Grand Rapids, Michigan, USA

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by mazeeff on Thu Sep 17, 2015 5:59 am

    Good points. I do use a manual reset GFCI for all my HiFi gear. Back in the late 60's, I was lucky enough to own a Marshall JTM100 Super Lead amp. These amps were SS rectification, and I do not recall any B+ (560V) delay circuit, other than the normal Standby function. That Marshall was played everywhere, and took quite a beating. In all the years that I played that amp, I don't ever recall replacing the power tubes. That amp saw more power outages and glitches than my Dynaco would ever see. My 67 Dynaco with SS, has been running fine for many years, other than a little 60 cycle hum the power transformer. I may get a little less tube life, but I don't seem to notice it!

    Mike

    deepee99

    Posts : 1337
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by deepee99 on Thu Sep 17, 2015 1:31 pm

    Tube Despot sells what appears to be the same thing as the WS-1, here https://tubedepot.com/products/solid-state-rectifier
    utilizing just a pair of 1N5408 diodes, for $9.95. It does not have an in-rush current limiter, however; I'd be loathe to use it without Bob's time-delay relays.


    Guest
    Guest

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by Guest on Thu Sep 17, 2015 9:21 pm

    mazeeff wrote:Good points. I do use a manual reset GFCI for all my HiFi gear. Back in the late 60's, I was lucky enough to own a Marshall JTM100 Super Lead amp. These amps were SS rectification, and I do not recall any B+ (560V) delay circuit, other than the normal Standby function. That Marshall was played everywhere, and took quite a beating. In all the years that I played that amp, I don't ever recall replacing the power tubes. That amp saw more power outages and glitches than my Dynaco would ever see. My 67 Dynaco with SS, has been running fine for many years, other than a little 60 cycle hum the power transformer. I may get a little less tube life, but I don't seem to notice it!

    Mike

    don't forget, new tubes these days are really not like the old ones, they are just not built the same way anymore. There are some exceptions perhaps, those so called boutique tubes, but their prices are just ridiculous!
    So, for the small price of a time delay pcb and an hour or so to build and install it, it is well worth while!!

    pedrocols

    Posts : 64
    Join date : 2014-11-24
    Location : Western MA

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by pedrocols on Fri Sep 18, 2015 8:36 pm

    Has anybody tried these delay boards on the m-125?

    deepee99

    Posts : 1337
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by deepee99 on Fri Sep 18, 2015 8:41 pm

    pedrocols wrote:Has anybody tried these delay boards on the m-125?

    I have 'em on mine. Highly recommended, even if you're using tube rectifiers. Gives the filaments 15-20 seconds warm-up before the B+ comes crashing in.

    pedrocols

    Posts : 64
    Join date : 2014-11-24
    Location : Western MA

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by pedrocols on Fri Sep 18, 2015 8:46 pm

    pedrocols wrote:Has anybody tried these delay boards on the m-125?
    Ok thanks! I have been running the weber wz68 for close to a year now and have no problems. I do not listen loud or push these amps. However, my speakers are magnepans so I am sure even at low volumes it can be demanding on the amps.

    arledgsc

    Posts : 340
    Join date : 2012-11-30
    Location : SF Bay CA

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by arledgsc on Sun Sep 27, 2015 11:05 am

    I bought and installed the Tube Depot SS rectifier to replace the WZ68 in my ST120.  The time delay relay board is already set for 40 sec. delay so the tubes are plenty warm before HV kicks in.   I have no idea how much the B+ increased as a result but nothing has blown yet.  I had to really adjust bias down after installation though.  No diode rectifier hash noise.  And less heat coming off the amplifier which is a bonus.  I like better efficiency.

    I do have a minor concern using single 1N5408 rectifiers in the ST120 that have 1KV peak inverse voltage max rating. (See SS rectifier datasheet below for reference) This may be over spec in the ST120 but have always used an additional single 1N5408 on the output of the rectifier stage so have effectively two diodes in series at all times.
    Tube Depot SS Rectifier Datasheet

    If B+ has increased closer to 550V I will wire up my unused ST120 rectifier heater winding as a bucker with the incoming line voltage to effectively reduce the AC coming in about 5V.  This should reflect to 15-20V less HV AC at the rectifier input.  

    But it sounds very good if it holds up!!  Stable imaging with better bass control. Bob's hair is probably on fire so proceed with caution and YMMV.

    Sponsored content

    Re: Weber WZ68 now NOT recommended on Weber website!

    Post by Sponsored content Today at 12:29 pm


      Current date/time is Sat Dec 10, 2016 12:29 pm