# Copper Cap Rectifier Tube - WZ34 Replacement



## jimsz (Apr 17, 2009)

Hi all, I just finished a Weber amp head kit A540, had tested all the voltages, plugged in the tubes, the amp worked well for about 10-15 minutes, then the CCR tube sparked, smoked and blew. The fuse went but the tube fried. 

Does anyone know where I can get a replacement CCR tube locally in the Vancouver area?


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## Emohawk (Feb 3, 2006)

I think L&M can get them (or an equivalent). You could just use a GZ34 tube.


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## DavidP (Mar 7, 2006)

That happened to me a few years ago -- received a CC from Weber and it immediately turned into Ol Smokey... I emailed Ted about it and he requested that I return it (at his expense) and he immediately sent out a couple new ones that have been fine ever since. I expect if you contacted TA Weber directly about this, he'd send out a replacement. 
I doubt that you'd find a new CC locally here. If you want to go the tube route and need one quick, PM me as I have a couple GZ34s (JJ and MIJ Sylvania) that I could be persuaded to sell.


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## Wild Bill (May 3, 2006)

DavidP said:


> That happened to me a few years ago -- received a CC from Weber and it immediately turned into Ol Smokey... I emailed Ted about it and he requested that I return it (at his expense) and he immediately sent out a couple new ones that have been fine ever since. I expect if you contacted TA Weber directly about this, he'd send out a replacement.
> I doubt that you'd find a new CC locally here. If you want to go the tube route and need one quick, PM me as I have a couple GZ34s (JJ and MIJ Sylvania) that I could be persuaded to sell.


Sadly, Ted passed away a while ago. He will be missed. Of course, his company is still going strong!

Meanwhile, thetubestore.com - Audio vacuum tubes for your amplifier. carries Copper Caps. They're in Hamilton, Ontario.


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## WCGill (Mar 27, 2009)

I've used these in the past also. While a real GZ34 provides a soft start-up, the WZ34 won't. If that's one of the features you're looking for, stick with glass.


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## jimsz (Apr 17, 2009)

Hi Guys, well I did contact Weber and without question immediately sent me a new one. I found a GZ34 and am using that, the new CC I received will sit in my on the road bag as a backup. I couldn't find a CC locally but am glad to be using glass instead.

The amp is sort of finished. I'm waiting on a bag to install the reverb tank and there is still some background noise to get rid of. I followed the layout as prescribed but was told by someone who actually knew what they were doing to take the board out, take out the wires underneath the board and bring them to the top as he felt some of the wires underneath the board are causing oscillations by being either too close to each other or have crossed over each other.

I have already removed a few wires without the need to take out the board and have resoldered them on top. By moving them around a bit, some of the noise disappeared, so I think this may be part of the problem.

Here are some other problems that had me going for a while:

Bad capacitor
Bad tubes
Bad volume pot
Bad optocoupler


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## Emohawk (Feb 3, 2006)

Hey there. What type of noise are you getting? I just built a 6a20 & had to use shielded wire on the volumes to get rid of some noise. It was especially bad on the vibrato channel. Did you use the grounding scheme from the layout? Some of the guys on the Weber boards have come up with alternate approaches that lower the noise floor a bit.


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## jimsz (Apr 17, 2009)

The noise I'm getting is probably similar to the noise you had on your 6a20. I didn't use the grounding scheme but instead put in a grounding bar with only one attachment to the chassis and the other end to the ground plug. I'm going to try some of the alternatives mentioned, but I've already had one guy tell me I need to relocate the wiring under my board first and work with that.

Definitely though, I'm way over my head with this build but I have learned a helluva lot building it. I was told that if it worked perfect from the get go, I probably wouldn't have learned very much.


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## Emohawk (Feb 3, 2006)

Right on. If you did the under-board connections as they're on the layout it should be fine. The sensitive spots on these amps are the volumes, vibrato controls, and leads connecting to the footswitch jacks (specifically the vibrato, but I can't recall if the 5 series have switchable vibrato like the 6 series does). 

I would recommend grounding your pre-amp grounds to one side of the chassis (in the corner near the normal channel inputs) and the power section (PT grounds, filter caps, etc) on the other end of the chassis. I've used that approach on all but one of my builds and it seems to work great. This is the same approach the Weber forum guys recommend.

Another thing to try is to replace the filter cap board with a multi-section can cap, but in this case that may not be necessary as the runs should be relatively short & the board is mounted away from the pre-amp wiring assuming you've mounted it to the PT like the layout shows. Personally I don't like having those caps exposed like that. It's like the "death cap" on some old PTP amps!


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## jimsz (Apr 17, 2009)

Unfortunately, the under-board wiring is causing oscillations, even though I did follow the layout. I think you're dead on with the vibrato controls and the leads to the footswitch jacks, I've already worked with those so much that the legs of the optocoupler broke off and I had to make a new one. 

What I have is a ground bar running the length of the board, all copper components, one end is connected to the chassis and the other to the ground plug. All grounds are connected to this bar. I don't believe the noise I'm hearing is ground hum and I've had two amp techs check the grounding and they said it's good. If I change this setup now, I might as well start over again.

I like the idea of changing the filter cap board as you mentioned, as it is an extremely tight fit that required a few mods of my own to make it fit without getting in the way of the other components and also not having the leads of the caps touching the chassis. I heard this amp build is much the same as 'building a ship in bottle' - I would have to agree. Next time, I'm going for the chassis' that has a lot more room.


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## Emohawk (Feb 3, 2006)

Yeah - I hear ya. Those reverb/vibrato Fenders are a tight fit at the best of times. I have some pics posted in my 6A20 build thread. Very busy in there, so lots of opportunity for noise issues.

Interesting about the under-board wiring. That's gonna be painful to correct. Wish I could help ya!


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## jimsz (Apr 17, 2009)

I hope it's not too painful. It should take a few minutes to desolder some of the connections on one side of the board, most likely I'll use the pot side as opposed to the tube side, a whole lot less connections there. Take out the three screws holding the board in place and lift it up vertically. I should be able to desolder the underboard wiring, put the board back and solder everything up again in a couple of hours, which I've been told will greatly benefit in reducing the noise problem and providing easy access to all the connections there.

I forgot to take pics. I'll try to remember and post some here so you can see the ground bar assembly.


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## jimsz (Apr 17, 2009)

Howdy Emohawk, I tried rewiring both input jacks with shielded cable soldering the 68k resistors right from the tube and running the shielded cable over to the jack side while soldering the shield to ground on that side only. Much of the noise disappeared on the normal channel but there's still quite a bit of noise on the vibrato channel. I haven't touched the under board wiring yet and am wondering if that's where the problem lies.

Should I place a grommet in the hole for the foot switch jack and isolate it?


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## Emohawk (Feb 3, 2006)

Did you use shielded cable on your volume pot wipers also? That got rid of most of the noise on my vibrato channel. My normal channel was already very quiet so I didn't bother with that side.

Isolating the footswitch & reverb jacks should help also. Just remember you still have to ground them with the unused grounding lug/washer that came with them..

I used plastic "snap cap" washers on both sides & insulated the threads with some heat shrink. You could head to your local electronics store & pick up some isolated RCA jacks or isolation washers. Whatever you feel comfortable with.


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## jimsz (Apr 17, 2009)

No, I didn't use shielded on the wipers, but did remove them from under the board, shortened them up and ran them along the inside, moved them around until most of the noise disappeared. I think as a final precaution, I'll use the shielded on them. It seems to have got rid of quite a bit of noise.

I think my reverb pot is toast. The meter shows it halfway on as OL, not good. When I dial it round, the noise increases quite a bit. I'll swap that out. So far, a good sized handful of parts have crapped out with this kit.

Also just found out that the reverb tank has to go in last and come out first before the chassis. The OT is too tall and won't slide under the tank which is installed upside down on the top back of the cabinet. Another flaw in the design.

My next build might be from another company, me thinks.


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## jimsz (Apr 17, 2009)

I dropped a brand new tube on the carpet, but it didn't survive the impact. Don't you hate it when that happens.


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## Emohawk (Feb 3, 2006)

I hear what you're saying. The thing is if you want a kit with better quality parts that's more of a simple assembly, you will pay substantially more. I would have paid more than double for a "better quality" BFDR kit.

In my case, I did upgrade some of the components, most notably the pots (the ones that come with the kits are garbage), the signal caps (not really necessary depending on who's opinion you prefer), and a couple of misc hardware items like the lamp assembly & the fuse holder. Overall no complaints, but I did eliminate some of the trouble spots before assembly.

Now the other Weber kit I currently have in the hopper, a Java, has been problematic. I haven't decided if I'd try another of their kits. Depends on if I get that one up & running to my satisfaction


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## jimsz (Apr 17, 2009)

Well, I replaced the reverb pot, the broken tube and have added some quality shielded cable for the input jacks and volume wipers.

And, the reverb has now stopped working altogether. This is the part where I'm banging my head against a wall, you just can't see it. 

The noise has now been more centralized between the reverb and volume pots. If I turn the reverb up to about 2, the noise drops off almost completely but can be brought back in with the volume pots. More banging of the head at this point.


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## jimsz (Apr 17, 2009)

I can't figure out why the reverb does not work anymore. If the reverb unit itself has failed, is there anyway to test it?


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## Emohawk (Feb 3, 2006)

Not sure what to tell you. Have you tried the Weber boards? There's a few guys there who've build dozens of the things & they've encountered just about everything.


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