Fried a Quad of EL84's I Bought From Hi-Test Guitars/Am I At Fault?

[Wagster]

I bought a quad of El84 Tungsram from Hi Test. When I talked with Gregg on the phone I said I want the tubes to sound complex on the cleaner tones on my AC30 TBX. He recommended the Tungsram tubes. When I put them in my amp they kept popping the filament fuse in my tbx. I sent them back to Gregg and he said they were fine. When I received them back they started making weird noises and then lost power. I sent them back and he asked me to take a pic on the inside of my amp since two of the Tungsrams were fried. He them preceded to tell me it was because my screen resisters were 1/2 watt and were failing with the high current drawling Tungsram. He said it was a flaw of the TBX amps. I though all AC30's uses 1/2 watt screens? I've been running the piss outta this amp for years and have only blown one 5ar4 and a Tung-Sol ECC83 in eight years of heavy gigging. I had a quad of Jan 84's that I got almost 3 years out of and never an issue with JJ's. I even had my tech talk to him and tell him that everything is running fine on the amp. We changed the screen grids to 5watt ceramics while we had the amp open but I don't it as being the culprit.

The bottom line is he is not going to replace the blown tubes and says it's my fault. Am I at fault here? I'm out $200.

 

[Moot]

I'd say that if your tech checked the 1/2 watt resistors and they tested fine then it's the tubes. It is very possible that one of the resistors has died a bit over time.
Were the two tubes that blew on the same side? That would indicate an internal problem.

 

[Jon Silberman]

I myself won't post substantively in threads like this one anymore because I'm tired of how many of the people who start them using the forum and us to get a positive-for-them-response from the vendor and then deleting the thread so as to deny others the opportunity to find the experience in later searches when relevant to them. Wagster, I'm not for a moment accusing you personally of being ready to do this - I've just become burned and shy about these sorts of threads.

 

[Wagster]

I myself won't post substantively in threads like this one anymore because I'm tired of how many of the people who start them using the forum and us to get a positive-for-them-response from the vendor and then deleting the thread so as to deny others the opportunity to find the experience in later searches when relevant to them. Wagster, I'm not for a moment accusing you personally of being ready to do this - I've just become burned and shy about these sorts of threads.

Jon,
I'm sorry that you've been through that in the past. I'm just asking because I'm being told that it's my fault and I'm not sure that it is. I just wanted to ask the experts. I promise that I won't delete this thread.

 

[riffmeister]

Jon, I'm sorry that you've been through that in the past. I'm just asking because I'm being told that it's my fault and I'm not sure that it is. I just wanted to ask the experts. I promise that I won't delete this thread.

We had a big slug-fest over tubes from Hi-Test in the not too distant past. The guy that purchased them was unhappy with their performance also got his tech involved. It was big and ugly, went on for pages and pages (not unlike the 2R thread running concurrently) and ultimately the guy that started the thread deleted the whole thing.

Fasten your seatbelt!

 

[ac/dcfan87]

I'm by no means any expert. Is this a modern amp? A lot of modern amps won't accept NOS tubes. It has to with pin 1 on the amplifier. But you stated that you've used JAN tubes with no issues.

Sounds like those tubes were toast. I bought a pair of Tungsrams that blew on me but don't take that for anything. I would trust your amp tech because he is most likely to know a lot about tubes and your particular amp.

Maybe ask your tech if he can talk to the hi test guy.

That's why I don't buy NOS tubes anymore. Too big of an investment for a risky venture. AC30s are known for cooking EL84s too. They run really hot, it's part of the sound.

If I do but nos tube or old tubes I buy em cheap on eBay.

 

[Wagster]

We had a big slug-fest over tubes from Hi-Test in the not too distant past. The guy that purchased them was unhappy with their performance also got his tech involved. It was big and ugly, went on for pages and pages (not unlike the 2R thread running concurrently) and ultimately the guy that started the thread deleted the whole thing.

Fasten your seatbelt!

On crap I'm sorry guys.

 

[Wagster]

I'm by no means any expert. Is this a modern amp? A lot of modern amps won't accept NOS tubes. It has to with pin 1 on the amplifier. But you stated that you've used JAN tubes with no issues.

Sounds like those tubes were toast. I bought a pair of Tungsrams that blew on me but don't take that for anything. I would trust your amp tech because he is most likely to know a lot about tubes and your particular amp.

Maybe ask your tech if he can talk to the hi test guy.

That's why I don't buy NOS tubes anymore. Too big of an investment for a risky venture. AC30s are known for cooking EL84s too. They run really hot, it's part of the sound.

If I do but nos tube or old tubes I buy em cheap on eBay.

It's a 2000 AC30tbx.

 

[SirGilmour]

Uhhhhh. If you told him the amp ahead of time and he knows enough about that amp to tell you its a bad design(after the fact) then why did he recommend tubes that wouldnt work properly?

 

[ac/dcfan87]

http://www.kcanostubes.com/content/modern-el84-amps-and-nos-el84s

This is the article i was referring to. But your amp s/b able to accept NOS tubes I would think... That is probably not the issue just wanted to point it out though.

Seems odd though that every other EL84 works fine and then you pop the Tungsram in and it craps out. Does not sound like a coincidence to me but what the hell do I know.

I would trust your amp tech.

 

[garret]

Have to ask, did you check the bias after swapping the tubes?

I'm not familiar with Vox amps but is 1/2 watt a bit low for a screen resistor?

 

[NewDr.P]

anyone who sells old tubes has to have this policy, they wouldnt be able to profit otherwise.

its the nature of tubes- they can last 10 minutes or 10 years. you pay extra, you dont get any extra guarantee.

apparently the ones you bought were the 10 minute variety. id never buy nos tubes for this very reason.

 

[Wagster]

anyone who sells old tubes has to have this policy, they wouldnt be able to profit otherwise.

its the nature of tubes- they can last 10 minutes or 10 years. you pay extra, you dont get any extra guarantee.

apparently the ones you bought were the 10 minute variety. id never buy nos tubes for this very reason.

I've learned my lesson the hard way. I'll stick with good ole JJ's.

 

[ledzep618]

Wow, another great customer service story from Hi-Test. Another reason why I scratched him off my list. He knew of a "flaw" with the amp he was sending you tubes for and still sent them with basically a buyer beware return policy. sounds skeevy.

 

[SirGilmour]

anyone who sells old tubes has to have this policy, they wouldnt be able to profit otherwise.

its the nature of tubes- they can last 10 minutes or 10 years. you pay extra, you dont get any extra guarantee.

apparently the ones you bought were the 10 minute variety. id never buy nos tubes for this very reason.

This is true and why for EL84 power tubes I stick with JJ's. I have been known to try some NOS 12AX7's but usually they are only around $30-40 so thats not such a hit if they fail.

 

[Ilduce]

The way I see it is if Hi Test recommended these tubes for your amp and your amp is in good health he should either give you a refund or replace the tubes with another set of similar value that will work in your amp. Just my opinion.

 

[Wagster]

I just want a set that works in my amp. A while back I needed a set of EL84's and nobody around me had a set except for a music store that sold old used gear. They sold me a quad of ANOS Jan EL84's for $40 and they sounded great and lasted for almost 3 years of heavy gigging. That's what made me want to go the NOS route and buy the Tungsrams. I was hope for improved tone and longevity over the JJ's. If this is the norm for NOS dealers I can no longer afford to take the risks.

 

[RussB]

Wow, another great customer service story from Hi-Test. Another reason why I scratched him off my list. He knew of a "flaw" with the amp he was sending you tubes for and still sent them with basically a buyer beware return policy. sounds skeevy.

Buying NOS tubes seems to be a risky deal these days. I'll stick with MikeK and Koray over there in Turkey

 

[DrainBamage]

Hitest shows no "guaranty" anywhere on the website. Probably a good idea to know your venders first.

 

[sickboy79]

Sorry to hear this happened. I previously bought tubes from Greg at Hi Test about 14 years ago and didn't have a problem. Some of the tubes are still going strong. But, I usually buy from Mike at KCA now. I have no reason to think your amp is the problem personally. I've used NOS tubes in more modern EL84 based amps (Budda, Matchless, etc) and have not had a problem.