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Fender DRRi broke

Discussion in 'Amp Tech Center' started by xjazzy, Jul 10, 2018.

  1. xjazzy

    xjazzy Friend of Leo's

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    My Fender DRRi broke up today.
    I only get low very distorted (fuzz like) sound.
    Both channels.
    Checked all the tubes and speaker.
    Disconnected reverb.
    I belive power is not getting to power tubes as I checked BIAS and values are very very low.
    I'll be opening it up to see if I can find something before looking for a tech (hard to find a good one around here). What should I look up to?
    Caps?
     
  2. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    Voltage on each tube is always a good place to start, unless you see anything obviously damaged like a cooked resistor or blown capacitor. That should at least tell you where the problem could be.
     
  3. EddieLocrian

    EddieLocrian Tele-Afflicted

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    I would get a tech.
     
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  4. xjazzy

    xjazzy Friend of Leo's

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    I would too, and I eventually will, if I had a good one around.

    Thanks @corliss1 I'll take a look at it as soon as I can.
     
  5. viccortes285

    viccortes285 Tele-Afflicted

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    Check your fuse
     
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  6. xjazzy

    xjazzy Friend of Leo's

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    Well, caps were already discharged and then I saw they're leaking.
    New caps needed, right?
    How do I find this in Europe? IMG_20180710_201439.jpeg
     
  7. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    They are common values from tube amp supply places, or even most electronics shops. If you are comfortable working with high voltages go ahead and change those out. If you're not, get it to a tech.
     
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  8. rze99

    rze99 Poster Extraordinaire

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    Bad luck

    FMIC Support are good in these situations. Email them .
     
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  9. LudwigvonBirk

    LudwigvonBirk Tele-Holic

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  10. rze99

    rze99 Poster Extraordinaire

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    Try support first they send out replacement parts to you IME.
     
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  11. powerwagonjohn

    powerwagonjohn Tele-Meister

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    In what year was your DRRI made?
    Thanks John
     
  12. xjazzy

    xjazzy Friend of Leo's

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    I found the parts at retroamplis.
    I bought the amp new in 2005.
     
  13. Dacious

    Dacious Poster Extraordinaire

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    Wow - this amp.may have been sitting around a few years before you got it. Those Illinois caps are a bit notorious, but mostly the 450 volt ones in early Hotrods.

    Yes, don't run the amp, you don't want to risk a short in the foil taking out your power transformer.

    This may have cooked one or both tubes - check for burnt components in the bias and grid sections.
     
  14. xjazzy

    xjazzy Friend of Leo's

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    Everything looks fine except those caps.
    I'll change it and see how it goes.
     
  15. Dacious

    Dacious Poster Extraordinaire

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    Probably OK. That's definitely enough to screw up your tone, but good!
     
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  16. LudwigvonBirk

    LudwigvonBirk Tele-Holic

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    Be careful draining the caps first, and de-soldering (tons of documented info on how to do both). And make sure to get the +/- orientation right on the new installs. If you do all 3, this is an easy fixit job*.

    *famous last words.

    But, you can do it! :cool:
     
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  17. robrob

    robrob Poster Extraordinaire Ad Free Member

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    The leaking caps do need replacing but they are probably not your main problem. If they were really weak you'd have a loud hum problem.

    Don't forget to replace the 100uF 100v C36 bias cap too.

    What do you mean by "I checked all the tubes"? Your problem is probably a bad tube. I would start by trying a new rectifier tube since your bias numbers were very low.
     
    Last edited: Jul 11, 2018
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  18. clintj

    clintj Friend of Leo's

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    Once the other work is done, you may need a set of power tubes. Your original symptoms of low, fuzzy volume and low bias can be easily explained by one dead power tube.
     
  19. xjazzy

    xjazzy Friend of Leo's

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    I tried a new set of power tubes, rectifier and all the other tubes.
    Yes, there's a loud hum, guitar's volume is very low and distorted.
    Every other cap in the circuit looks in perfect order so I'll start with these and see how that goes.
     
  20. Wally

    Wally Telefied Ad Free Member

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    Ime and imho, those electrolytics need to be replaced....all of them. If you cannot do this, put the amp away until either you have studied enough to understand these circuits to some extent so as to be able to do the work yourself or you can find a tech.
     
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