DRRI dead, do I put it in trash and buy a Tone Master?

Discussion in 'Amp Central Station' started by BorderRadio, Sep 11, 2020.

  1. BorderRadio

    BorderRadio Doctor of Teleocity Silver Supporter

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    Seriously though, I switched it on the other day and nothing. Checked the fuse, seems ok. The lamp doesn't come on, and yes the bulb is ok. I know that's hardly enough info, but busy week, but I can get it on 'the bench' this weekend. Any ideas where to start troubleshooting next?

    It's a 2013, I didn't mod it, planned to ride it hard in the warranty phase but of course, I'm out of warranty now.
     
  2. Preacher

    Preacher Friend of Leo's

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    I did not have the same amp, but a similiar issue. Apparently the plug in the back of the amp almost had pulled out (it was one of those computer type plug units) and it was not making contact.
    I checked the wall, the fuse, the signal path, the fuse again, the wall again, and even opened it up and put a voltmeter on it and found no voltage. Then I bumped the cord and saw a spark... Ah it was not plugged all the way in, it was just barely in the housing.
     
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  3. Ed Storer

    Ed Storer Tele-Holic Silver Supporter

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    Check the power cord. I had a laptop power supply that mysteriously stopped working and purchased a new supply, only to find out that the cord was bad and the rest of the unit was working.
     
  4. teletail

    teletail Tele-Afflicted

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    Yes, throw it out. Solid State amps NEVER break.

    dog looking.gif
     
  5. jondanger

    jondanger Poster Extraordinaire Ad Free Member

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    Seems like you’ve got to start by taking voltage measurements from before and after the PT. Once you have verified that voltage is getting through the PT right, then you might want to start by checking the heater circuit. Is the pilot bulb in line with the heaters like it is on the BF/SF models?

    Just checked the schematic - pilot is in line with the heaters.
     
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  6. Drew617

    Drew617 TDPRI Member

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    I don't know your comfort level working on these but I'd say if you know you can do it safely, certainly worth safely discharging caps and at least checking continuity from the cord to fuse/switch and PT, and output from the PT.

    Maybe "put it in trash" is hyperbole but if your patience or budget for dealing with it ends there, I'd think the cab-chassis-transformers should be valuable to someone else either as a repair or rebuild project. :)
     
  7. schmee

    schmee Doctor of Teleocity Silver Supporter

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    Are the tubes lighting up?
    Bad jack?
    Take that puppy and put an eyelet board in it. Not that hard and now you have a hand wired amp. I did one years ago. Iused the existing smooth pots etc.
     
  8. unixfish

    unixfish Doctor of Teleocity Silver Supporter

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    If it were mine, I would first check the plug (does the DRRI have a PC style cord?) and the outlet. Often the most obvious gets me. I've had outlets get "crusty" behind the entertainment center - un-plug and re-plug them about 5 times and voila.

    Beyond that would take a circuit tester or a tech.
     
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  9. Controller

    Controller Friend of Leo's Silver Supporter

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    Fix it and buy a TM. Then let us know how you like it.
     
  10. BorderRadio

    BorderRadio Doctor of Teleocity Silver Supporter

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    Thanks guys, bad joke to a real problem, though I do want to try a Tone Master :) I'm fairly comfortable but very much a newb to working on tube amps. The most I've done is re-cap a few amps (on PCBs). I have a DMM, that's about it.
     
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  11. jondanger

    jondanger Poster Extraordinaire Ad Free Member

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    Make sure you’re getting 120 VAC from black to ground and between the PT primaries. If not, you have a problem between the PT and the wall voltage. Fuse and any other wired or socketed connections should be checked.

    If you’re getting 120 in those spots and still having a problem, make sure you’re getting 6.3 VAC on the heaters. Since the light is out, I’m guessing your issue is before the PT or in the heater circuit.
     
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  12. Engine Swap

    Engine Swap Tele-Holic

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    Not getting power = open connection = easy fix
     
  13. ce24

    ce24 Poster Extraordinaire

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    Fuses can look good and not be good. Especially the ones with the wound wire on the outside. Do a continuity check on it.
     
  14. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    No power is always a quick check - it's easy something cheap and easy, or something expensive an easy.

    If you're comfortable doing so, watch the AC component come in. Right at the plug, across the fuse, into the PT. Make sure all that is present. Then, check the AC on the secondary of the PT - you can check the heater lines and the high voltage lines for AC, although you'll need to pull the rectifier to check the AC.

    Go from there. One of those points will be missing some AC, and that will tell you where the problem is.
     
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  15. stantheman

    stantheman Doctor of Teleocity

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    Do these Re-Issues have a Tube Rectifier?
    If they do - it’s the rectifier.
     
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  16. Dreadnut

    Dreadnut Tele-Afflicted

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    Yeah, what ce24 said
     
  17. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    @stantheman - the rectifier would not be involved in the pilot light or tube heater circuit, so it should still give the appearance of "turning on" even if it produces no sound.
     
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  18. rangercaster

    rangercaster Poster Extraordinaire

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    Buy the Tone Master, and stash the DRRI somewhere and eventually you'll get around to fixing it ...



    Problem solved !!!
     
  19. scooteraz

    scooteraz Friend of Leo's

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    Well, if you have your heart set on the Tone Master, by all means trash your DRRI by sending it to me and get the Tone Master....
     
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  20. Tim S

    Tim S Tele-Holic

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    You could do much worse than a Tone Master. (But I’d trash what you have and get a Tone King instead)
     
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