Help! My Blues Jr. III is Making Me Crazy!

Discussion in 'Amp Central Station' started by Flatfoot, Apr 7, 2020.

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  1. Flatfoot

    Flatfoot Tele-Meister

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    in 2017, I bought a new Blues Jr. III. I bought it from an online retailer. It has been plagued with problems. Pretty much from day one, it has some mysterious (to me anyway) issue where I can turn it on and play for a few minutes and it sounds great. Then suddenly, the tone becomes thin, splatty, farty, and the amp loses a lot of power. So, after the first time or two of experiencing this, I took it to the nearest music store that was listed as a Fender Authorized Service Center. Their tech looked it over, and said that he couldn’t find anything amiss. He said he did re-flow some of the solder joints, but otherwise didn’t know what to tell me. He charged me $60.00 because he said that Fender would only cover the work if he could document a problem.

    I really want to like this amp, as it is the perfect size and power for my needs. I have replaced the factory speaker with a WGS ET-65. Great speaker! When the amp works, it sounds great, but I can’t gig with it because it isn’t dependable. I’m not real savvy when it comes to tube amps, so I would appreciate any feedback from the brain trust. I just really don’t know what to do next! BTW, I have replaced all the original tubes with JJ’s. Any thoughts are welcome!
     
  2. dlew919

    dlew919 Poster Extraordinaire

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    I’m going out on a limb and thinking it might be your power supply. How you’d test that I don’t know.


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  3. Whatizitman

    Whatizitman Friend of Leo's

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    When did you change the tubes? Why did you not return it when it first gave you issues? The big online retailers have 30-45 day return periods.

    Edit: is it random? Only happen after heated up and playing for a while? Go back to normal after restarting? Etc...

    The tech didn’t look hard enough. Is it still under warranty? I know Fender doesn’t do the 5 year thing anymore. But you bought it new in 2017. Contact Fender directly.

    Take it to an independent and knowledgeable tech. A real tech could figure it out. These are popular and highly documented amps. Unless you are ready to learn how to work on a high voltage device with a PCB yourself, that would be my best recommendation. Anything else we can recommend here would likely involve testing with a meter and/or soldering.
     
    Last edited: Apr 7, 2020
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  4. Flatfoot

    Flatfoot Tele-Meister

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    ————————————————————————————————————————-
    Actually, I first replaced the original power tubes after one of them lit up like a Christmas tree. That was really the first issue and I had owned the amp for probably three months at that point.

    Yes, it is somewhat random, but always seems to occur after it heats up awhile. It does always seem to be ok when it is first turned on.

    I will try to contact Fender directly and see what they say. Some of the stories I’ve heard from others doesn’t exactly instill confidence.
     
  5. Dacious

    Dacious Poster Extraordinaire

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    Where do you live? A known problem with these amps is they're set to run the tubes hot. Plus the resistors aren't the highest quality. The bias and grid resistors get cooked and it throws the amp.

    A good tech can determine the current draw and replace any bad components and rebias it to where it should be.
     
    Last edited: Apr 7, 2020
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  6. Treehouse

    Treehouse Tele-Meister

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  7. stefanhotrod

    stefanhotrod Tele-Holic

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    You should‘ve return the darn thing as the first issues pop up, too bad.
    Let a good and experienced tech check it out and fix the problem. After that: sell it and buy a good handwired tube amp (2nd hand).
     
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  8. dan1952

    dan1952 Friend of Leo's

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    These amps are known for problems. I know, BJR folks will blow me up...
    I wouldn't take one on the road, myself.
     
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  9. Matthias

    Matthias Friend of Leo's Gold Supporter

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    I have one that I like but the screen grid resistor blew the first time a tube went bad — fortunately within warranty. They have issues.

    I’m not really qualified to comment past that, but my AC4 had an issue where it faded out and I came to blame the pots when they were set to barely on.
     
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  10. dlew919

    dlew919 Poster Extraordinaire

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    You guys saying they have issues, I hope you don’t jinx me. Mine has been flawless for about 6 years. New set of tubes, that’s it.


    Sent from my iPad using Tapatalk
     
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  11. ronzhd

    ronzhd Tele-Holic

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    You have the Blues JR. naysayers and I get that, however two words for the OP; AMP TECH. Since you didn't take it back under warranty, it's really your only option. Find a guy that a local Mom and Pop guitar shop recommend. I have a USA made Blues JR., never a problem, replaced the tubes once.
     
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  12. jvin248

    jvin248 Poster Extraordinaire

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    .

    The tech you had look at the amp didn't find the problem because the problem only shows up when the amp gets hot -- how long and how loud are you playing it at that point? Amp techs are not able to put in an hours worth of playing time to find a problem like that, track down the problem, repair it, then spend another hour running it hot to ensure it still works right. Your repair bill would be more than the amp is worth just from testing time and you'd be unhappy about that.

    You might be playing in a hot sweaty closet of a corner room of your house and the amp tech is in an air conditioned lab.

    "a problem well defined is a problem half solved" -- figure out exactly how you can repeat the amp failure every time.

    Possible problems: bent tube socket from swapping tubes or contacts dirty, scorched regular resistor near the tube that was replaced, failing ceramic power resistor, bad electrolytic capacitor.

    .
     
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  13. darkwaters

    darkwaters Tele-Afflicted

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    Mine was also a lemon. The only thing in it of any quality was the Eminence speaker (and everyone replaces it. LOL) Had it repaired one last time and then traded it in for a PRRI.

    Best... move... ever. :)
     
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  14. popthree

    popthree Poster Extraordinaire

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    i had poor luck with a BJ. I won't own another. it went through el84's like crazy. kept red plating tubes after a short time. only good thing was it was easy to flip, even when being transparent about its appetite for tubes. they are wildly popular even though they have some inherent flaws.
     
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  15. Henry Mars

    Henry Mars Tele-Afflicted

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    The first step is to re-solder the tube sockets ... it is the biggest problem with this amp and usually fixes these kinds of problems.
     
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  16. popthree

    popthree Poster Extraordinaire

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    from what i have read, and heard from techs, the tube sockets are mounted directly to a PCB, and that is a core problem. the pots and input jack are also mounted in the same way.
     
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  17. SoK66

    SoK66 Tele-Afflicted

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    I've played a couple of these on jams, etc. and they sound respectable. However, the PCB build as you have noted puts me off. If I can't fix it I won't own it.
     
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  18. Chiogtr4x

    Chiogtr4x Poster Extraordinaire

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    I've had mine since 2000 (it's a blonde 1999 I bought used ) and it has needed occasional maintenance ( by a great DC-area amp tech, he is THE Fender amp guy a true asset for us!)
    And I'll be the first to admit that since it was ( then, 1999) a budget tube amp, there are compromises in the BJ design that need attention over time, and you just take care of them.

    But, I bet I've done 1000 gigs with it, it sounds great today.

    Here are the items my tech friend has worked on, over the years:

    - replaced Reverb pan ( I did this)

    - replaced stock speaker ( I did this, with Eminence Neo mag Lil' Texas, for the headroom maybe, but mainly to reduce amp weight )

    - replaced power switch, Input jack ( metal nut instead of cheapo plastic)

    - longer power cord

    - tech installed resistors and bias adjust pot ( for him to use NOT me- currently JJ power tubes)

    - replaced all pots/ knobs ( these have litte nibs inside chassis that break , making poor contact with solder traces inside PCB, or something)

    - replaced power Transformer last year ( what can I day, amp died/NO sound right at the start of Festival gig!)

    - tech friend did ' Twin Tone Stack' mod ( opens up midrange for more or less than stock configuration, woke up my amp EQ a bit)
    He is very patient to show me ( with a chopstick or pencil) all the electronic stuff, I try to understand- Ha!

    So a lot of things changed or repaired over 20 years, but honestly it's been very dependable.
    Wish I could use it, now!
     
    Last edited: Apr 8, 2020
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  19. Whatizitman

    Whatizitman Friend of Leo's

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    Blues Juniors are so popular, of course we're gonna hear about faulty ones. But I bet the vast majority are ok to fine. Take it to a good tech. It will get sorted out.
     
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  20. pinkpanda

    pinkpanda TDPRI Member

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    billm would've been able to help you out for sure.. So sad he's not with us anymore. But like everyone else says: take the amp to a good amp tech. Blues Jr is a well documented amp. These issues should be repairable for a solid amp doctor
     
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