#1
My amp has been giving me a bit of grief recently, and I wasn't sure what was causing the problem. Initially, there were volume inconsistencies, and the volume pot was quite noisy, so I cleaned the pots out, and that seemed to fix it for a while. Most recently though, the signal would go very faint before cutting out completely. 

While I could think of a few possible causes for this, I haven't changed the tubes since I bought the amp head (a bad habit, I know), and so I think it's time. The amp takes EL84 tubes, so my question is, can I change them for any brand of the same type, or is there anything that it might be incompatible with?
WHOMP

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#2
Any brand you want. Just make sure
to adjust the bias if your amp isn't fixed bias and you are getting EL84s, matched!

I recommend JJ tubes.

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#3
Quote by Perverockstar69
Any brand you want. Just make sure
to adjust the bias if your amp isn't fixed bias and you are getting EL84s, matched!

I recommend JJ tubes.

Cool, thanks! I'm not sure how to find out if my amp is fixed bias, but if I'm pretty much changing the tubes like for like, would it be a problem? I hear that adjusting the amp bias is tricky and potentially dangerous if you don't know what you're doing. 
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#4
What amp is it?

Mesa Royal Atlantic
Orange Rocker 15
Marshall Class 5C
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PRS Swamp Ash Limited Custom 24
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#5
Hayden Mofo 30 watt. I don't think they make the exact model that I own anymore (I bought it about 5 years ago), but they still produce an updated model that I believe is basically all the same insides, just with a few extra bells and whistles.
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#6
I just checked, no fixed bias on that amp. Take it to a tech with your new tubes.

Mesa Royal Atlantic
Orange Rocker 15
Marshall Class 5C
Emperor 4x12 Silver Bells
Yamaha THR10
PRS Swamp Ash Limited Custom 24
LTD Viper 500 with Duncans
#7
Quote by Perverockstar69
I just checked, no fixed bias on that amp. Take it to a tech with your new tubes.

Ok, thanks - any idea how much that would set me back roughly? I've been trying to find quotes online and no luck so far. Luckily, there are a lot of guitar stores nearby that do amp servicing.
WHOMP

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#9
Quote by Perverockstar69
http://www.thetubestore.com/Tubes/EL84-6BQ5-Tube-Types/JJ-EL84-6BQ5 almost $13 per tube, I don't know how much a tech charges for the bias adjustment.

Oh wow, that's quite a bit cheaper than some of the tubes I was looking at - I thought it would be at least £60 (not sure how much that is in USD) for a full set.
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#11
Quote by Perverockstar69
I just checked, no fixed bias on that amp. Take it to a tech with your new tubes.

Cathode bias means you can pop the new tubes in without taking it to a tech for bias.

Fixed bias (confusingly) is the one that needs to be biased when changing tubes.
#12
Quote by Roc8995
Cathode bias means you can pop the new tubes in without taking it to a tech for bias.

Fixed bias (confusingly) is the one that needs to be biased when changing tubes.

Ok, yeah after a little digging around I found that it is in fact cathode bias. So does this mean I can just pop the old ones out and new ones in, like changing a lightbulb?
WHOMP

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#13
Yes. Be careful not to bend the pins. You can wiggle the tubes side to side a little to get them in or out but don't twist or force them especially if the pins aren't lined up.

Make sure you get a set of matched power tubes, too.
#14
Roc8995 My bad, thank you for the correction

Mesa Royal Atlantic
Orange Rocker 15
Marshall Class 5C
Emperor 4x12 Silver Bells
Yamaha THR10
PRS Swamp Ash Limited Custom 24
LTD Viper 500 with Duncans
#15
Quote by donender
Oh wow, that's quite a bit cheaper than some of the tubes I was looking at - I thought it would be at least £60 (not sure how much that is in USD) for a full set.

That's because JJ's are cheap, mediocre sounding tubes, but most people can't tell the difference.

<waits to get flogged>
"Practice doesn't make perfect. Perfect practice makes perfect." -some dude
#16
Quote by Prime2515102
That's because JJ's are cheap, mediocre sounding tubes, but most people can't tell the difference.

<waits to get flogged>


Actually, you are the only person I've read/heard saying JJ are mediocre tubes...

Mesa Royal Atlantic
Orange Rocker 15
Marshall Class 5C
Emperor 4x12 Silver Bells
Yamaha THR10
PRS Swamp Ash Limited Custom 24
LTD Viper 500 with Duncans
#17
Quote by Prime2515102
That's because JJ's are cheap, mediocre sounding tubes, but most people can't tell the difference.

<waits to get flogged>

I've read a few reviews and the only negative things I've heard are about tubes that are flat out faulty. I have a gig in a few weeks and I don't have much of a budget to splash out, so I may just go for JJs and hope for the best. It's probably quite evident that I don't know a huge amount about tubes, so I don't really know what to look for when judging the quality.
WHOMP

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#18
I’m a believer of where you buy the tubes matters.

I’m in the USA and don’t know where to buy them in Europe but find a shop that tests the tubes themselves.

I use eurotubes dot com and they have their own tube testing gear to match up the tubes for what you want/need.

I’ve used them for 3 amps and couldn’t be happier.
Guitars:
Ibanez RG1570 Prestige
Jackson Kelly KE3 - MIJ (Distortion/Jazz)
Jackson DKMGT Dinky (EMG 81/85)
ESP E-II Eclipse Custom (JB/'59)
ESP LTD EC-1001FR (EMG 81/60)
Fender MIM Strat

Amps:
Mesa/Boogie Dual Rectifier Roadster 212
Laney IronHeart IRT-Studio
Peavey Vypyr 30
Peavey ReValver Amp Sims
TOOOO many T.C. Electronic Pedals. . .
#19
Quote by donender
I've read a few reviews and the only negative things I've heard are about tubes that are flat out faulty. I have a gig in a few weeks and I don't have much of a budget to splash out, so I may just go for JJs and hope for the best. It's probably quite evident that I don't know a huge amount about tubes, so I don't really know what to look for when judging the quality.

Oh sure, if you're on a budget they'll do the job, and do it well for the price. I'm just saying, there are much, much better tubes available, but you pay a premium for them (especially NOS).
"Practice doesn't make perfect. Perfect practice makes perfect." -some dude
#20
Prime2515102 they are no different than any current production el84 imo. I have three quads of JJ's el84s in my drawer and two quads in two amps atm. I have others too. I

Preamp tubes are a different story though. JJs quality is as good as the other guys in current production. BUT NOS is the way to go if you want to drop the cash. I purchased 50 jj 12AX7 a year or so back. That will last a damn long time. I have a tpn of other tubes as well both nee and NOS.
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#21
trashedlostfdup I swapped the stock JJ EL84's in my 5150 LBX with Telefunken Black Diamond EL84's and the difference was obvious. It turned a really good amp into a kick ass amp. I had the same results with my Mesa Heartbreaker with EL34's and 6L6's (vs. stock Mesa tubes and Tung Sol's). Granted though, the Telefunkens are about at the top of the heap for new production tubes.

The only thing I don't like about the Telefunkens is they have a tiny bit too much compression for my taste, but for metal and lead stuff that's a good thing. This applies to all three types AND their 12AX7's and 12AT7's. Maybe it has something to do with the cryo process, I don't know.
"Practice doesn't make perfect. Perfect practice makes perfect." -some dude
#22
Prime2515102 what ever ya say captain :eyeroll:

but seriously at triple the cost. I bought those jj 12AX7s for $8 a pop. I have quite a few NOS tubes. They are strictly used in recording for me.

Also the new Telefunkens come out of the same factory as JJs. They are just further tested, cryo'd and burned in.

You also have to keep in mind that i have 21 tube amps to maintain.
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Quote by andersondb7
alright "king of the guitar forum"


Quote by trashedlostfdup
nope i am "GOD of the guitar forum" i think that fits me better.


Quote by andersondb7
youre just being a jerk man.



****** NEW NEW NEW!
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2017-04-13 RUN AWAY from COMPUTERS!!! TCE? RANT ALERT!!!
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2017-02-21 How to Hot-Rod the Hell of your Stratocaster for $50! (Tuesday 2017-2-21)
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#23
trashedlostfdup I don't think they are JJ's. The innards don't look the same at all.
"Practice doesn't make perfect. Perfect practice makes perfect." -some dude
#24
Quote by Prime2515102
That's because JJ's are cheap, mediocre sounding tubes, but most people can't tell the difference.

<waits to get flogged>


Yup, you're one of the very few people who has much bad to say about JJ's these days.

Interesting that you think the Telefunken Black Diamond EL84s are so much better, since they are made by JJ.

They're simply a re-branding exercise. The cryo process is not exclusive to that brand name, either.

One of my favorite vendors is Bob at Eurotubes dot com. While almost every brand name touts that their tubes are "tested," Bob actually has some of the best testing gear on the planet, and I've had really good matched sets of tubes from him over the years. I'm using far fewer tube amps these days (I've only got 15 left, with over half of them in storage). One rack ordinarily carried a Mesa Triaxis, a Carvin Quad-X and a Carvin TS100. I think a retube on that mess would have required 18 12AX7 tubes (there are nine in the Quad-X alone) and four EL34s (or 6L6 or 6CA7s) in a single go.

I think Amazon has the Telefunkens for $26 a pop (I've seen them for as much as $38), while a matched quad of JJ's runs about $48. I'm not sure that the Telefunkens are at the "top of the heap" for sound quality (yeah, we've seen them at the LA Amp Show, where the folks evaluating them are among the top in the business), but they're right up there on cost.

In your defense, you didn't realize that the Telefunkens were just rebranded JJ's. And if you're not buying your JJ's from someone who tests them thoroughly with high end testing gear, you probably get the ones that folks like Eurotubes dot com reject, that get sent to other vendors.
Last edited by dspellman at Nov 14, 2017,
#25
Quote by dspellman
Yup, you're one of the very few people who has much bad to say about JJ's these days.

Interesting that you think the Telefunken Black Diamond EL84s are so much better, since they are made by JJ.

They're simply a re-branding exercise. The cryo process is not exclusive to that brand name, either.


+1
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Quote by andersondb7
alright "king of the guitar forum"


Quote by trashedlostfdup
nope i am "GOD of the guitar forum" i think that fits me better.


Quote by andersondb7
youre just being a jerk man.



****** NEW NEW NEW!
2017-07-07 2017-07-07 Update and a Chat On Noise Constraints *** NEW FRIDAY 7/7
2017-04-13 RUN AWAY from COMPUTERS!!! TCE? RANT ALERT!!!
2017-03-02 - Guitar Philosophy 1001- Be Prepared For the Situation (Thursday 2017-03-02)
2017-02-21 How to Hot-Rod the Hell of your Stratocaster for $50! (Tuesday 2017-2-21)
Resentments and Rambling from a Guitar Junkie
---> http://trashedengineering.blogspot.com/
#26
Quote by Prime2515102
That's because JJ's are cheap, mediocre sounding tubes, but most people can't tell the difference.

<waits to get flogged>

Said no-one ever.

What is the theory behind tube burn-in?  trashedlostfdup Why is it better?

I could be wrong, but I would assume that burn-in is done within a few hours of the life of a tube to ensure that their bias doesn't drift. But I would think that almost all tubes you can buy are matched to take this into account anyway? It sounds like marketing hoopla.
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Last edited by T00DEEPBLUE at Nov 14, 2017,
#27
Quote by T00DEEPBLUE
Said no-one ever.

What is the theory behind tube burn-in? trashedlostfdup Why is it better?


The burn in just heats it more evenly after production. I think there are people on both sides of the camp on if it's worth it or not.

The cyro i don't know a ton about. Maybe @dspellman has more info.
WTLT 2014 GG&A

Quote by andersondb7
alright "king of the guitar forum"


Quote by trashedlostfdup
nope i am "GOD of the guitar forum" i think that fits me better.


Quote by andersondb7
youre just being a jerk man.



****** NEW NEW NEW!
2017-07-07 2017-07-07 Update and a Chat On Noise Constraints *** NEW FRIDAY 7/7
2017-04-13 RUN AWAY from COMPUTERS!!! TCE? RANT ALERT!!!
2017-03-02 - Guitar Philosophy 1001- Be Prepared For the Situation (Thursday 2017-03-02)
2017-02-21 How to Hot-Rod the Hell of your Stratocaster for $50! (Tuesday 2017-2-21)
Resentments and Rambling from a Guitar Junkie
---> http://trashedengineering.blogspot.com/
#28
According to Telefunken Marketing, the 24-hour burn-in "Is to heat the cathode and remove any impurities or unevenness on the cathode coating. By burning the tube in, it reduces any popping, static sounds and erratic behavior. This is proven to benefit the vacuum tube's lifespan and durability."

The cryo treatment "cools the tubes to -300F, leaves them there for 24 hours and then brings them to room temperature. Cryogenically treated vacuum
tubes have a lowered noise floor, less microphonics, expanded dynamic range with more tonal depth, and a more consistent tone for a longer lifespan.


As trashedlostfdup notes, there are folks on both sides of whether this does anything at all (other than raise the price of the tube and allow cork-sniffer tube weenies a chance to point at bullet points on the spec sheets). As mentioned, I've listened to amps with and without them at the LA Amp show. Since it IS a marketing bullet point, I should point out that there are other sources for cryo-treated tubes. I should also point out that there are absolutely no guarantees that these tubes will actually last longer or sound better than any other tube.
#29
Well guys, I've ordered a set of four JJ EL84s, so they should be here within the next week or so. I have only just heard of this cryo treatment business, from one particular website (hot rox UK) that have a disclaimer at the bottom of their product blurbs saying "we do not believe in cryo freezing tubes", and I wasn't sure if it was a mark of quality or what. 

The part of this process I was most anxious about was actually removing the old ones, but they just popped right out. The tubes that I originally had in were Ruby Tubes, and after checking online, they are a little more expensive than JJs, but hopefully there won't be too much disparity in sound quality. 
WHOMP

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#30
Ruby EL84s are rebranded JJs. The price difference is for QC, which is redundant if you buy from a decent tube dealer. Any halfway decent tube dealer tests their tubes as well or better than Ruby, so there's no point in paying more for Ruby unless your only option is to buy off the shelf from a shop that doesn't test. 
#31
donender I highly suggest you pickup some quality electrical contact cleaner like DeOxit D5 and spray down the pins of the power tubes and insert, remove the tube several times until the tube glides in easily - you can feel the difference and you'll know when you're good.

I learned that the tube pins form a kind of "fingerprint" from the imperfections of the tube pins with the tube socket which can cause some contact issues with new tubes. Using the contact cleaner erases the "fingerprint" and allows the new tubes to form their own over time (and current).
Guitars:
Ibanez RG1570 Prestige
Jackson Kelly KE3 - MIJ (Distortion/Jazz)
Jackson DKMGT Dinky (EMG 81/85)
ESP E-II Eclipse Custom (JB/'59)
ESP LTD EC-1001FR (EMG 81/60)
Fender MIM Strat

Amps:
Mesa/Boogie Dual Rectifier Roadster 212
Laney IronHeart IRT-Studio
Peavey Vypyr 30
Peavey ReValver Amp Sims
TOOOO many T.C. Electronic Pedals. . .
#32
Quote by metalmingee
donender I highly suggest you pickup some quality electrical contact cleaner like DeOxit D5 and spray down the pins of the power tubes and insert, remove the tube several times until the tube glides in easily - you can feel the difference and you'll know when you're good.  

I learned that the tube pins form a kind of "fingerprint" from the imperfections of the tube pins with the tube socket which can cause some contact issues with new tubes.  Using the contact cleaner erases the "fingerprint" and allows the new tubes to form their own over time (and current).

Thanks for the tip, it was quite difficult popping them back in (did it with the old ones just to know how much pressure to apply), and I've got some contact cleaner lying around for some previous amp maintenance. 
WHOMP

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#33
Quick update - got the new tubes and they fit right in real easy, and sound great. It eliminated the problem I was having with the signal cutting out, thank god, because if the problem remained, then I would have probably meant that there was a wiring problem with the cab itself. 

Thanks for the help, guys!
WHOMP

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