Fender Blues Jr tube replacement

[@michaelarvizu418]

2 years later your video is still so helpful! Just replaced faulty Groove tubes in my Blues Junior with new JJ tubes and it’s like a new life for this amp. Big thanks Pedro!

[@pedrogiavani2330]

No problem. Glad you found it helpful.

[@tactikzzF1R3]

Very helpful video......thank you!!

[@stodgepodge]

Thanks for the helpful vid, just about to swap out mine! I'm wondering if the metal bar here 1:07 has any function beyond holding the tubes in place?

[@pedrogiavani2330]

To be honest, I don't know. But I suspect that the bar is also to support the tubes when moving the amp from place to place. The tubes are a bit fragile.

[@stodgepodge]

@@pedrogiavani2330 that would make sense, thanks Pedro!

[@CKC411]

How do you know when tubes are bad? Example, I have a Blues Junior and a Deluxe Reverb and both are noisy, which may be normal, but the Reverb is also very staticy. Any help appreciated. THANKS

[@life_is_a_pest]

You should have stated in the beginning that "not to touch the tubes with bare hands". Im like damn it too late now thanks for letting me know a head of time.

[@AnkurWow]

Great video! Thinking of buying a Blues Jr. and was curious what the tube changing process was on them. One question: How did you know which tube was bad to begin with? Thanks!

[@pedrogiavani2330]

You might want to look at this video that I did earlier: kzbin.info/www/bejne/mqSYeGukfNZ6rbs As I heard the tube "go away" I decided to replace all the tubes. Here is the first video I did on the BJ III Tubes: kzbin.info/www/bejne/nIu7fIKEndWsgbs Cheers.

[@adamburozski978]

Great video! Stop busting his balls over the gloves...I wear gloves in tribute to you my friend. You took all the anxiety out of my solid state mind as I made the switch to tube town. Many thanks.

[@davebarone506]

Very well spoken

[@MartinPEngebraaten]

I have little experience with changing tubes and the terminology here, but one of my "big tubes" (I believe that is one of the preamp tubes?) has lost its glowe. The amp is pretty much useless now. Do I need to buy a full set with all the 5 tubes? And in that case, where can I buy it from/what is the tubes called? Thanks

[@pedrogiavani2330]

I need a little more information before I can give you a complete answer. If you have a Fender Blues JR. like I have, the larger tubes are EL84s these are the power tubes. Yes, you should replace both with a matched pair. (Tube depot DOT COM) You didn't say where you are in the world, I only have experience buying tubes in Canada. Any guitar shop should have replacement tubes. If you can easily buy off of the internet, here is a full tube package to look at as well: www.opentip DOT COM/product.php?products_id=7252769&ats=product_landing I have no financial connection with this site, nor have I ever used it. As always, Buyer beware. Cheers for now. Pedro

[@joe5583]

You don't need to wear gloves when you handle tubes, you're thinking of halogen lightbulbs, completely different for tubes

[@pedrogiavani2330]

I disagree, with one provision. I have always used gloves on large power tubes. So it has become a habit when handling any tubes to use gloves. I have used and replaced lots of small tubes like: 6LF6s, 807s, 6LQ6s. I have also used and replaced larger ones like 3-500ZG, 4CX1000A, TB3/750. This is my first time playing with low power tubes and maybe they don't run as hot as some of the tubes I have used. Although, I did melt the grids out of a set of 811As that I had handled with my bare hands. (that is another story, but rubber gloves aren't available when you are 600 miles south of the north pole and need to do repairs)

[@pedrogiavani2330]

@JimiRox As I have said before, I have handled large power tubes. 1000 to 2000 watt tubes were common with what I did. Ask the chief tech at an AM radio station if he would change those large tubes with bare hands or if they would use gloves. You may be right about these low wattage tubes used in guitar amps, I will grant you that. But I will continue to use my gloves when playing with tubes as when I open up a 5K or 10K watt amp I don't want sloppy habits to bite me on the back side. Cheers and have fun.

[@fullcirclejams]

and just wasted more $ on groove tubes that have prob never been tested for quality since fender took over !

[@geet77777]

Anyone know where to get that metal piece that holds in the two larger tubes? i cant find one anywhere. i just replaced all my tubes and my amp goes "bwwwwaaaaaaahhhhhhh". no idea what's wrong.

[@armgarza9175]

Will a tube amp work with one burned tube? Also, I took off the tubes cause I was cleaning the amp. Do I have to wait 30 minutes to warm them up? Thanks

[@seanobrien89]

Any idea why I am blowing the main fuse when I have a tube go bad? Thanks

[@pedrogiavani2330]

I don't know with out seeing the amp. Best if you take it to a local amp tech.

[@seanobrien89]

@@pedrogiavani2330 I actually fixed it before like 5 years ago I remember seeing the bad tube light up then immediately after the fuse would blow. Was just wondering why yours went bad but the fuse didn't blow simultaneously. Anyways thx for response Merry Xmas!

[@pedrogiavani2330]

@@seanobrien89 I was playing the amp when the tube went out. You might have had a short in the grid of the tube. That would have blown the fuse. I just melted the grid a bit so it sagged, but didn't short out. JUst a guess here.

[@seanobrien89]

@@pedrogiavani2330 ok thanks yes 2nd time hopefully it’s a Ez fix

[@uncledoug9934]

​@@seanobrien89watched a video by a guy in England. Fuse blowing of a Blues Jr. ended up being a diode fried through a series of reactions.

[@Hendrix67297]

My blues jr just blew a tube. Making a terrible noise. Do these blow like fillament light bulbs? Do i have to change all 5 of them? I think its one of the large power tubes that have blown. Will it be black and show a broken fillament?

[@pedrogiavani2330]

You may want to look at this video first: kzbin.info/www/bejne/mqSYeGukfNZ6rbs I am not sure what you mean by a "filament light bulb", but I am going to guess "No". You shouldn't have to replace all five of the tubes, but if it is a power tube, you will want to get a matched pair. With out looking at the amp/tubes I don't know if it will be black or not. I suspect not. Be aware that brand new tubes are sometimes duds from the factory. I had a brand new tube fail. I was able to move it to a different socket (V1 if I remember right) Good luck with your repairs.

[@KowboySantos]

perfect video. grazie!

[@mns8732]

I missed the part that says, unplug amp from wall socket first.

[@MrAMF50]

What about the rating # on the power tubes? Shouldn't they be the same as it's a fixed bias amp.

[@pedrogiavani2330]

I am not sure what you are asking. A matched pair of power tubes came out, and a matched pair went back in. If I blow a power tube, I will put the matched pair of older tubes back in. does this answer your question? Cheers.

[@BenK.]

So the tubes on my Blues Jr III need to be changed. Do I have to set up the bias after that? Or is it fixed and I can play again after just installing the new tubes ?

[@pedrogiavani2330]

The bias is fixed, so just replace the tubes and you are OK. I would let the tubes "burn in" for about half to an hour of time before putting any input into the amp. Tubes now-a-days are not very well made so you may need to do some again.

[@donstewart368]

These are fixed bias. No adjustment.

[@AnneMcCueMusic]

Thank you! :-)

[@icarus7073]

Hi my tube went off like lightning buzzing then I turned amp off then when I turned back on it wouldn't go on so I think fuse went.. does anyone know exact fuse I need for blues jnr?? Many thanks

[@danbudai8360]

Hello, what type of preamp tubes did you use? Any specific positions v1 or v2 etc? Thanks

[@pedrogiavani2330]

I started out with a full set of Groove Tubes GT-12AX7-C One was bad (it seems that more and more tubes are just made poor right from the factory) I put a Sovtek 12AX7WB in V1 and left the GTs in V2 and V3. I kept the poor GT as it will work well in V3 if I loos that tube. It was V1 that was toast in the first place. Tubes don't make much difference to the tone of an amp (some people will disagree, but that is OK) just find ones that work.

[@danbudai8360]

Pedro Giavani , thank you. One more question. So i can easily go with 3 12AX7 tubes all the same brand? Do the preamp tubes need to be paired? Thank you.

[@pedrogiavani2330]

Yes, go with all three of the same brand. I went with the Sovtek tube instead of a Groove Tube because I had a good one to replace the bad one that had come from the store. I had bought three Groove Tubes at the same time to do the replacements. It is sad to see that even new out of the box tubes now are sometimes bad. The pre-amp tubes don't need to be matched as each does it's own job. V1 is the preamplifier. It has the most effect on tone. V2 re-amplifies or recovers the signal lost in the tone stack. It has a relatively minor effect on tone. V3 is the phase inverter. It makes mirror images of the signal and drives the output tubes, V4 and V5. It too is an amplification stage, and has a minor effect on tone. If you have a slightly bad tube you can likely use it in V3 without having it cause too much problems. That is what I will be using the Groove Tube that I replaced with the Sovtek tube. I hope this helps. Cheers.

[@danbudai8360]

Thanks Pedro for the help. Things are much clearer now. This was helpful! Cheers

[@timothyjay2012]

Pedro Giavani If you guys wanna try Great Pre Amp tubes try the Genalex Gold Lion Long plate 12AX7's and Mullard 12AX7 from Tube depot DOT COM. They text and Rate the tubes you buy and always make sure you order Long plate 12AX7's for Vintage Fender or Marshall Tones.

[@djoosterveen]

You don’t have to bias them?

[@pedrogiavani2330]

This is a fixed bias amp. So you don't have to bias it. Cheers.

[@aintnothinbutdablues]

Is there any advantage on putting an ECC81 on V1 ? Have you tried it? Its a common mod on the Fender HotRod, don't know if it has any advantage on a Blues Junior III

[@pedrogiavani2330]

Sorry for the slow answer. I have only put the same tubes back in that came out. I don't know if there is any benefit to changing out to a different tube, or if it is just a myth.

[@PillsBuryDoughBoy_]

What is a bias?

[@pedrogiavani2330]

I stole this, but it is well written: The best way to understand bias is to think of it like the idle setting on a car. Nowadays most cars have complex computers that control the idle, however, in the end the process is still basically the same as it has always been. The fuel and air mixture is adjusted so that the motor runs smoothly; too much of either and the motor won't run very well or even possibly not at all. The idea is to find the perfect balance for optimum performance. When it comes to tube amps the idea is basically the same, however, instead of fuel and air we are dealing with electrical current. The purpose of setting the bias of an amp is to find the optimum setting for the flow of current when the amp is idling. Too much and the life of a tube is significantly decreased and in extreme cases failure can occur; this is also referred to as "biased hot." Too little and unpleasant distortion (crossover distortion) is produced; this is referred to as "biased cold." The correct setting is crucial for an amp to perform at its best both functionally and soundwise.

[@PillsBuryDoughBoy_]

@@pedrogiavani2330 thanks

[@FirstAmericaFirst]

The Blues Jr is a fixed, non-adjustable bias amp (like Mesa).

[@donstewart368]

Not true, that's only for halogen tubes. Doesn't hurt these tubes to touch them at all.

[@pedrogiavani2330]

So Don, what is the largest power tube you have ever handled? Unless it was north of 5000 watts, I will stand by my replies made to the other dozen or so people that have gotten ahead of you in the comment line.

[@mrader217]

Dude, why not mention which the bad tube is?? Is the one on the right the reverb?? Those who know didn't need this video

[@csnymoodiesfan]

If one of my Power Tubes burned out, do I have to replace both?

[@pedrogiavani2330]

I would replace both at the same time. Why did one burn out? Is there a problem with your amp, or are the tubes older/haven't been replaced after lots of use? You want to have a matched pair, and if your tubes are older and have had a lot of use, both tubes are/were ready to burn out.

[@mariek130]

Pedro Giavani Thanks for your quick response. Yes, I believe they've been there a while. Also, the fuse blew out a couple of weeks ago, so don't know if that was part of the problem.

[@黒人-m3w]

I am a amp tech. You don't have to wear rubber gloves when handling tubes. The oils from your hands do not make the tubes wear out quicker. The oils from your hands do not effect the functionality of the tubes whatsoever. I don't where you get your information from , But it is incorrect.

[@pedrogiavani2330]

Please read my other replies. What are the largest power tubes you have handled? Have you handled a 10,000 watt tube? I have. so at this point, you do you. and I will do me.

[@onixtheone]

You don’t have to wear gloves, that “leaving oils on the glass ruins the tubed” is a myth

[@pedrogiavani2330]

Please read my replies to others who had this same comment. I stand by what I have said before, for the reasons that I have stated.

[@stratcat7162]

You can definitely get a better grip with those latex gloves you can pull nose hairs really easy too

[@jarveysorensen5502]

I've heard the same thing too but on halogen bulbs on your car you can touch the bulb just not the top tip that is black they say the oils from your skin to make the light explode but I still like to keep the bulbs clean

[@danielhartman5086]

Wrong as long as your hands are clean you don't need rubber gloves to put tubes in your amp. I have been doing it for years and never had a problem.

[@pedrogiavani2330]

You and I will have to agree to disagree. As stated in other replies, I have my reasons. I will continue to use the gloves, and anyone else who wants to use other methods if OK with me. Cheers.

[@andre991]

I'm having a noise in my Blues Jr Tweed. Could it be bad tubes? I recorded this video to demonstrate: kzbin.info/www/bejne/f4DHZnqBqql7obM

[@pedrogiavani2330]

I am not sure, I would first swap the V1 and the V3 tubes. the V3 is the Phase Inverter tube and only uses 1/2 the tube. V1 is primary gain, V2 is recovery from the tone stack. Let me know if this works.

[@andre991]

@@pedrogiavani2330 I did that, but the problem persist. Actually, I swapped randomly the 3 small tubes. Also swapped the 2 power tubes. Today I noticed one of the power tubes gets hotter and more incandescent than the other. I'm gonna replace both and see if it helps. Thanks for your help!

[@pedrogiavani2330]

@@andre991 Cheers

[@donstewart368]

There are better tubes than grove tubes.