Brand new amps with power tube issues

fusedbrain

Well-known member
First off, I'm not blaming any of the following on Diezel, or the 2 distributors that handled my amp before it got to me, as I've come to expect this whenever I take delivery of an amp from a courier, but it's getting to be a damn pain in the ass....Not the first time this has happened.

So I took delivery today of a brand new, still sealed in the factory box Diezel VH4. The amp had to go from Germany to B.A.D in California, to Diffussion Audio in Montreal, and then to me in Toronto, so it's logged some serious time in the back of a truck.
When I first fired it up, it sounded OK - kinda, but not quite"right". Definately not "brand new, legendary VH4 kinda "right", if ya know what I mean.... A little disappointing actually!
Given all the miles on the thing, I figured I should probably check the power tubes before I get down to some serious tone tweaking and trying to dial the amp in. Sure enough, the power tube situation was a mess.
The 4 - KT77's in the amp look like a matched quad of JJ's, all labeled as "69ma" ( which probably doesn't mean much in absolute terms, but would indicate they were a matched set at the factory ) and I'm sure everything was fine with them when the Diezel guys boxed the amp up and sent it to Cali.
But now at my place, after traveling half way around the world, the tubes are drawing, in order - 33, 26, 42, & 39 ma @ 470v on the plates according to my meter. That basically renders that quad of JJ's useless, and the 39 & 42 ma tubes probably wouldn't have lasted very long either if I hadn't checked. That's 80% dissipation :shocked: Kinda helps explain the lackluster tone too.

Anyway, I had a matched quad of KT77's in the tube stash, so I'm up and running with all 4 tubes biased @ 34ma-35ma, but this is not the first time this has happened. Probably more a reflection of the state of modern tube production than anything else, but it's still annoying as hell :doh: I'm starting to wonder if it would be better for manufacturers to wrap the 4 power tubes together in a giant wad of bubble wrap, and pack them like that, rather than ship the amp with the tubes in the sockets? I know that opens up a whole other can of worms with the end users having to install power tubes in the sockets when they get the amp, but the current method is less than ideal.

OK, rant over. Just wanted to vent a bit :D

Oh ..... and by the way....the amp is kicking some major ass now :rock:
Everything people say about these amps is true :2thumbsup:
Pretty happy with the purchase to say the least!
 
KSR ships amps with the tubes wrapped separately and put in the headshell. Took me like 5 min to install them when I got mine and get up and running. Everything was fine too. He shipped to me from the US to CAN too.
 
Stealthtastic":1cqzxt6x said:
KSR ships amps with the tubes wrapped separately and put in the headshell. Took me like 5 min to install them when I got mine and get up and running. Everything was fine too. He shipped to me from the US to CAN too.
Yeah, that's exactly what I'm talking about with wrapping up the tubes. Seems like a no-brainer. Not sure why more companies don't do it.
 
That's a bummer, but like you said, that amp traveled a LONG ways before getting to ya. Sucks for sure, cause tubes aren't cheap!


Glad you got it up and running and that your enjoying it :thumbsup:
 
Glad you got it back to ass-kicking! Totally sucks having to deal with that, but at least you had some spares.

Have you emailed Diezel about this? Just curious... I haven't needed to contact them, but all I've ever heard was that they have great customer service. With everything I've been hearing lately about JJ tubes and reliability, I would think that trying to minimize potential damage, as in wrapping them separately in bubble wrap during transport, would be the least every amp company would be interested in. I mean, it costs them quite a bit to send another set of tubes via international shipping. Honestly, I'm beginning to wonder why anybody is still using JJs at this point. I mean, they do sound good, when they're working. But with all the failures and short life, I'd be seriously considering switching to something else. Too bad =C= isn't still in business (last I heard, that is... and I know they made some great tubes).
 
ChurchHill":18xghjaf said:
Glad you got it back to ass-kicking! Totally sucks having to deal with that, but at least you had some spares.

Have you emailed Diezel about this? Just curious... I haven't needed to contact them, but all I've ever heard was that they have great customer service. With everything I've been hearing lately about JJ tubes and reliability, I would think that trying to minimize potential damage, as in wrapping them separately in bubble wrap during transport, would be the least every amp company would be interested in. I mean, it costs them quite a bit to send another set of tubes via international shipping. Honestly, I'm beginning to wonder why anybody is still using JJs at this point. I mean, they do sound good, when they're working. But with all the failures and short life, I'd be seriously considering switching to something else. Too bad =C= isn't still in business (last I heard, that is... and I know they made some great tubes).
Nah, I wasn't gonna bug Diezel or Diffusion Audio about this. It's not really their fault. They could ship me a new quad from Germany and it could be the same deal. I'm driving distance from The Tubestore in Hamilton, Ontario, so I just go down there and bring home tested quads when I need em.

I really just wanted to point out that today's tubes aren't that robust, and that it's a good idea to check the tubes after the amp does any traveling, especially if it doesn't sound like you expected. It's frustrating, but it's just the reality of dealing with tube amps in 2017.
And yeah I miss =C=.
There's a thread in the Friedman sub forum where Dave talks about how the latest JJ's are complete shit. I've had brutal luck with JJ el34's ( E34L's ), and just junk them if an amp shows up with them installed, but this is the first issue I've had with their KT77's. I've been using them for some time and never had an issue til now. I think Dave said he's using New Sensor EL34's now, so maybe I'll try them next. The VH4 certainly doesn't need the extra bottom end from KT77's.
 
I have found some of the best matched power tubes to be TAD. Gold Lion is a good KT77 replacement for the VH4 and retain their matched minimums. I don't know what it is about JJ's, but soon as you throw the juice to them and burn the grit off the plates, their current wanders. One exception though.....find a company selling APEX Matched quads. APEX matched will be burned in and also matched with 2 voltages. I have some APEX matched JJ's and they stay in range.
 
steve_k":3j2gnzib said:
APEX matched will be burned in and also matched with 2 voltages. I have some APEX matched JJ's and they stay in range.

I live within driving distance of Antique Electronics and, AFAIK, all their power tubes are matched by Apex. Three times in the last year I've had to buy replacement tubes for two different matched quads I got from them. Now, it's made a lot easier due to the specs. being listed on the Apex decals at the base of each tube. So I just call them, read off what I need and they go try to find something very close in the warehouse. But the quad of =C=s I bought was expensive and there aren't a lot of them left to match when one goes bad. Of course, the two from that quad that failed did so after the 90 day warranty period. So now I'm about $330 into what's no longer that matched of a quad. That's not including what I spent to replace the socket the last one took out with it. I put them in my DSL 100w head the other day, because those heads bias per side. So I put the two identically matched tubes in one side and the slightly mismatched tubes in the other side and biased them independently as pairs. Sounds pretty good. But who knows how much more time I'll get out of these? Not spending the money for them again. JJs will do just fine next time.
 
Rick Lee":68wvgrhd said:
steve_k":68wvgrhd said:
APEX matched will be burned in and also matched with 2 voltages. I have some APEX matched JJ's and they stay in range.

I live within driving distance of Antique Electronics and, AFAIK, all their power tubes are matched by Apex. Three times in the last year I've had to buy replacement tubes for two different matched quads I got from them. Now, it's made a lot easier due to the specs. being listed on the Apex decals at the base of each tube. So I just call them, read off what I need and they go try to find something very close in the warehouse. But the quad of =C=s I bought was expensive and there aren't a lot of them left to match when one goes bad. Of course, the two from that quad that failed did so after the 90 day warranty period. So now I'm about $330 into what's no longer that matched of a quad. That's not including what I spent to replace the socket the last one took out with it. I put them in my DSL 100w head the other day, because those heads bias per side. So I put the two identically matched tubes in one side and the slightly mismatched tubes in the other side and biased them independently as pairs. Sounds pretty good. But who knows how much more time I'll get out of these? Not spending the money for them again. JJs will do just fine next time.

I have gotten some shit tubes from them as well. They weren't APEX matched or labeled. That sucks though. Maybe someone is getting some stickers made with the APEX logo and slapping a logo on.

I have been buying straight off of Reverb from https://reverb.com/shop/audio-tubes-direct and can't complain. Tung Sol seems to have stepped it up a bit. The 6L6 STR's are sweet. The EL34's are nice too.
 
So many stories about traveling gear and tube destruction, I feel for all who have been stricken by this.
Tony Fay at Phaez Amps sells his builds with the option of tubes or not and the build prices reflect that. I would like to see other amp builders big and small offer the same. A majority of us switch out glass
as soon as we receive an amp or we end up replacing travel weary tubes anyways. It would save $ and avoid disappointment. My .02
 
I've never had an issue with amps shipped with the tubes in. One time a guy shipped with them removed and just threw them into a ziplock bag and taped it to the amp. It arrived as a bag of glass shards. Such an idiot. But he didn't argue with me and refunded me enough to fix it.
 
That's not including what I spent to replace the socket the last one took out with it
This is the part of tube failure that a lot of folks seem to forget, and is the issue I'm most concerned about. 480 volts DC can really make a mess!!
I can deal with having to replace a tube or 2, but what I DON'T want is any collateral damage to the amp. Fuses and screen grid resistors are not too bad, but sockets, and in the worst case, losing an OPT, is something I want to avoid. Especially when it's a newer $4k amp.
 
Well, it wasn't that bad. The socket and new resistors cost maybe $7 and took me 30 min. to replace. But it could have been worse. This is why I don't get upset when fuses blow. Those fuses are letting me know to fix an issue before more expensive damage occurs.
 
All of these reasons are why I bought Maxi-matcher tube testers. I don’t put a tube into my amp that hasn’t been tested first.
 
psychodave":3i4vgnvm said:
All of these reasons are why I bought Maxi-matcher tube testers. I don’t put a tube into my amp that hasn’t been tested first.

I hope that works for you, but testing well at the beginning doesn't mean it's not going to take a dump on you, usually at a gig or band practice. My =C= quad sounded amazing for a good six or seven months of heavy band duty in my '69 100w clone build. Then one day (at band practice, of course) I looked in the back and noticed one tube was all white and frosty up top. Sounded fine, but that tube had lost its vacuum and was dead. Got AE to match it pretty closely, and that replacement tube is still fine. Then a month ago, another one of that original quad blew when I dimed the amp, taking the socket out with it. That's why I always have my Boss Katana with me when it's a band thing. Always need a backup. I usually have a spare quad of power tubes that are close enough in bias, that I can throw them into the head in an emergency. But I don't sleep well at night with that as a backup plan for the next day's gig.
 
psychodave":3n7473dm said:
All of these reasons are why I bought Maxi-matcher tube testers. I don’t put a tube into my amp that hasn’t been tested first.

no shit. i have mine too and use both the power and preamp testers regularly. culled a lot of tubes, put a bunch in the garbage and called out a few tube companies sending so called matched quads.
 
steve_k":w1v0tynt said:
One exception though.....find a company selling APEX Matched quads. APEX matched will be burned in and also matched with 2 voltages. I have some APEX matched JJ's and they stay in range.

My case is probably the exception, but I recently received a pair of Apex matched JJ EL34s that were 7mA apart. I’m sticking with Valve Queen for my new tubes. Her matching is the tightest I’ve seen thus far.
 
guitarded_1":2phlcwrg said:
steve_k":2phlcwrg said:
One exception though.....find a company selling APEX Matched quads. APEX matched will be burned in and also matched with 2 voltages. I have some APEX matched JJ's and they stay in range.

My case is probably the exception, but I recently received a pair of Apex matched JJ EL34s that were 7mA apart. I’m sticking with Valve Queen for my new tubes. Her matching is the tightest I’ve seen thus far.

Laura will take the time to burn them in long enough then match them. This is really the only way to do it right.
 
steve_k":1qr9f9zo said:
guitarded_1":1qr9f9zo said:
I’m sticking with Valve Queen for my new tubes. Her matching is the tightest I’ve seen thus far.
Laura will take the time to burn them in long enough then match them. This is really the only way to do it right.
I'll second that. Laura's great to deal with!
 
fusedbrain":ozbbl2ne said:
Nah, I wasn't gonna bug Diezel or Diffusion Audio about this. It's not really their fault. They could ship me a new quad from Germany and it could be the same deal. I'm driving distance from The Tubestore in Hamilton, Ontario, so I just go down there and bring home tested quads when I need em.

I really just wanted to point out that today's tubes aren't that robust, and that it's a good idea to check the tubes after the amp does any traveling, especially if it doesn't sound like you expected. It's frustrating, but it's just the reality of dealing with tube amps in 2017.

And yeah I miss =C=.

There's a thread in the Friedman sub forum where Dave talks about how the latest JJ's are complete shit. I've had brutal luck with JJ el34's ( E34L's ), and just junk them if an amp shows up with them installed, but this is the first issue I've had with their KT77's. I've been using them for some time and never had an issue til now. I think Dave said he's using New Sensor EL34's now, so maybe I'll try them next.
Yeah, I agree with you. Not a big enough deal to not only wait on the tubes, but also not to bother Diezel with, especially when any replacements may have the same issue. You're right about that, too.

Saw that thread about Dave talking about recent JJ quality issues. That sucks, but, yeah, just part of the reality of dealing with tubes amps. It's been this way since the last of the American and British companies stopped production in the early 80s (maybe late 70s). I think there's only three factories left in the world: Sovtek/New Sensor, JJ/Tesla, and Shuguang. Then again, how big is the market for tubes these days? Outside of MI, you've basically got the audiophile people and the military (who also have or recently had huge stockpiles).

Next time my Herbert needs tubes, I'll probably talk with Laura at Valve Queen and see what she thinks. Probably a set of Gold Lions or some flavor of EH/Sovtek/Tung Sol/Mullard/New Sensor. Mine should be good for a while, hopefully, and I've got some backups. Six Gold Lions is going to be expensive and it sounds like we're reaching the bottom of the barrel with =C= with the current failure rate. Maybe JJ will get it together. Maybe =C= can magically resurrect itself. Stay tuned... film at 11... ;)
 
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