Fender Pro Junior IV - hum issues

Discussion in 'Amp Central Station' started by Jode, Dec 28, 2018.

  1. Jode

    Jode TDPRI Member

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    Hi everyone,

    I just took delivery of a new Pro Junior IV - unfortunately, it has quite a bad hum. This occurs with nothing plugged into the amp and is not affected by the knob settings at all. It fades in as the amp warms up and comes ‘on’ a few seconds after switching it on.

    Any advice on obvious fixes? I’m an experienced player but not experienced in doing amp tweaks - same old AC15TBX has served me well for almost 20 years so never had cause. I don’t want to be doing too much troubleshooting on a brand new amp - I know some noise can be expected but this is definitely louder than should be acceptable. I hope it’s an easy fix because I love the sound of the thing otherwise. Thanks in advance for any tips.
     
  2. tery

    tery Doctor of Teleocity

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    Exchange it .
     
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  3. teleblueman

    teleblueman Tele-Meister

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    I just bought one and although it is a bit noisy with the volume turned up (due to the circuit), there is no hum. I have heard these amps are hit or miss regarding this issue. The best advice I've heard is to swap out the V-1 tube. However, since it's more of a hum than a hiss, it may be a grounding issue.
    I agree with Tery, you should exchange it
    FWIW.....I just bought my pro Jr a few days ago. When I played it at home, I thought it was a bit "hissy" with the volume cranked & guitar volume down. Also, the speaker is a bit harsh (which I expect until it's broken in properly). Anyway, I played it at home for several hours before gigging with it the same night (I mean its so damn cute I just had to).
    Miked up through the PA all those little issues just melted away. It sounded glorious with my P-90 Les Paul, & just as good with my Tele.
    The Pro Jr. needs to be cranked above noon to really shine, it's not really a "bedroom" amp for sure.
     
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  4. Dacious

    Dacious Poster Extraordinaire

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    It's probably the output tubes but as it's new, exchange. Hum when gain is turned up can be a feature but hum with everything zero'd is not a good sign.
     
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  5. Jode

    Jode TDPRI Member

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    Thanks for the advice, everyone... it chimes with my own thoughts that I can handle a bit of hiss in my bedroom as the volume rises, but a constant low-end hum is cause to exchange. Bought online to save £40 - I’m sure it’ll be fine, but perhaps would have been better off buying in the flesh in the first place.
     
  6. tery

    tery Doctor of Teleocity

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    I just bought a new Pro Jr III on line - it is dead silent .
     
  7. maxvintage

    maxvintage Friend of Leo's

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    Pro Jrs are great amps but they are famous for being noisy. It varies from amp to amp

    I bought a Pro Jr. III last year and it was noisy but not terrible. I did the usual mods the internet recommends--twisting wires, repositioning ribbon cables--and it got better, although changing tubes made a bigger difference. It's still a somewhat noisy amp compared to other amps I've had and compared to my solid sate amps. Still has a really great sound though.

    I think of as kind of like the price you pay for single coils, in terms of noise
     
    Last edited: Dec 29, 2018
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  8. Jode

    Jode TDPRI Member

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    The replacement arrived yesterday, and I'm very happy - it's as quiet as you could realistically expect in terms of hum or hiss, no issues.

    I really like it so far, and it is loud for its size - all things being equal, I'd have bought a '68 Princeton, but the lighter weight and cheaper price of the Pro Jr swayed me (I have my first child in the post so shouldn't really be buying gear at all!). I'm optimistic that it can stay just about clean at the volume I need for my bands. The cleans are very different depending on whether you crank the amp and ride the guitar volume, or just keep the amp at polite levels - my first impressions are that it's a little more versatile than I expected.

    I've heard that its touch-sensitivity makes it a bit unforgiving, and I do get that feeling... I've been playing a long time, but I think a sustained period of using this amp might enforce a bit more discipline on my playing. I have a Hahn Model C arriving very soon, which I've also heard is a little unforgiving... fun boot camp for me!
     
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  9. zombiwoof

    zombiwoof Tele-Afflicted

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    If the amp hums, it's because it doesn't know the words!.
    (sorry, couldn't help myself. There is always one idiot who posts this, in this case I am that idiot).
    Al
     
  10. LuthRavin

    LuthRavin Tele-Meister Ad Free Member

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    Mine arrived in perfect condition...well near perfect..before I even turned it on I noticed that one of the keepers that holds the leather strap in place was loose on one side(that might come completely loose upon carrying it around) so I had to pull the chassis out to get up inside the upper regions..got it tightened down everything put back in place. finally turned it on and.....zero hum...zero issues!! What I liked was the way it was so adjustable, between working the tone on my Tele and the amps single tone chicken head it was super easy to dial in... Perfect grab and go
     
  11. FrontPU

    FrontPU Tele-Holic

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    Congrats!
    Fender Pro Jrs are truly great amps.
     
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  12. joshbot

    joshbot TDPRI Member

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    Sorry if I'm reviving dead threads. I have one of these amps (2002 MIM) and it hummed something fierce.
    I did the wire twist mod and replaced all the tubes with JJ's. The most noticeable differences in the level of hum were from
    A. Replacing the EL84 power tubes
    this knocked the hum down by 50%
    B. Replacing the 12ax7 tubes
    this dropped it by another 25%

    I guess these amps are finicky and I still hear a background noise compared to my mesa rectoverb25, but its at least acceptable.
     
  13. richey88

    richey88 Friend of Leo's

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    Mine (IV) has a slight hiss, but otherwise sounds great, congrats!
     
  14. jimash

    jimash Friend of Leo's

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    I haven't messed with the wiring in mine, but someone on here said "old amps, old tubes, new amps, new tubes," and that made sense to me, so I stopped trying to be clever with the tubes.
    It works as it should, which means it actually doesn't sound so good till it's about half way up, and then it's very loud, so I never play it at home and to sits in the closet, but it works right. Noise and all.
     
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