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Help me revive an old Traynor YGM3!

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by JohnnyL, Jul 13, 2006.

  1. JohnnyL

    JohnnyL Member

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    I scored a '73 YGM 3 at my favorite flea market recently. I know the seller and he didn't know whether the amp worked or not. He brought it in at my request. It had been stored for a while. The Amperex tubes and other parts are worth what I paid! I brought it home and gave it a thorough visual inspection and found nothing obviously wrong or out of order. Today I thought I would try it out?

    Unfortunately, nothing happened when I turned it on. I should say that this version has a circuit breaker instead of fuses so I can't check there. Is it possible the breaker is bad? Can I check the breaker using a DVM?

    Please advise me of anything I can check out myself. I would like to use this amp as a learning experience and am in no real hurry for it to be in use. I thought I could have some fun and learn my way around an amp with this project.

    A trip to the library is in order as I try to get some reference material.

    I really appreciate any help you can send my way. I know my limits and will take it to a tech if and when I decide I'm ready to go that route.

    Thanks Guys,

    Johnny
     
  2. WaltC

    WaltC Member

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    Well....

    If nothing happens (no noise, no lights, no smoke, no fire <G>) then you've got to start at the cord, the circuit breaker, and the switch to see if you get 120V to the power tranny when you turn it on (CAREFUL! 120V AC at 20 amps or so is nothing to sneeze at). If you're getting 120V to the power tranny then you've got to start checking the PT secondaries (6.3 V for the heaters and the dreaded red wires, 300+V to the rectifier, this can kill ya') to see if the PT is ok. Since you're not getting any lights (right?) this is probably as far as we need go at this point.

    Yup, you can use a DVM to check the voltages. Remember the wall and 6.3 V and 300V before the rectifier are all AC (setting on the meter) and after the rectifier is DC in great gobs that can really kill you too.

    Let us know what you find out and be CAREFUL!

    Walt
     
  3. JohnnyL

    JohnnyL Member

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    Thanks Walt. I've got the schematic and will follow through that if I have the time this weekend.

    "If nothing happens (no noise, no lights, no smoke, no fire <G>) then you've got to start at the cord, the circuit breaker, and the switch to see if you get 120V to the power tranny when you turn it on (CAREFUL! 120V AC at 20 amps or so is nothing to sneeze at)."

    Nothing happens at all when turning the amp on.

    I appreciate your response and the information you provided. Very helpful indeed.

    I will update the thread once I have checked what you have indicated.

    Thanks!

    John
     
  4. doctorx

    doctorx Member

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    The Guitarmate is a great amp, I have one. When you get the amp working I recommend swapping out the speaker right away, the stock ones suck big time. I put an Eminence Private Jack in mine and the amp sounds great now.

    Regarding your problem, follow the advise posted. You can check the continuity of the circuit breaker but you'd have to disconnect it. That's probably not your problem anyway. This might help you some, too.
     
  5. donnyjaguar

    donnyjaguar Member

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    Those Traynor cct breakers work real' fast. When you reset it do you hear it trip when you plug it in? These were yet another feature that Traynor employed that others should have. Pete Traynor was a road musician first and great designer second and it shows in the practicality and durability of his designs. Traynor amp's were first built for the rental market so you know they're tough!

    That's a great amp, I'd love to find one of those. I have a YBA head myself.
     
  6. JohnnyL

    JohnnyL Member

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    Thanks for the responses guys. DoctorX-That link is a great resource and is parked in my favorites-Thank You.

    I hope to share some feedback this weekend.

    Take Care,

    Johnny
     
  7. Lammy

    Lammy Member

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    red fang red fang red fang!! good luck!
     
  8. JohnnyL

    JohnnyL Member

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    Lammy-I happen to have a Red Fang waiting in a box for a new home;) . I bought it for my '65 Ampeg Rocket II but I haven't installed it yet. It will probably pull double duty serving either of these amps!

    John
     
  9. Label Bob

    Label Bob Member

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    I have a late 70's YGM 3 I put some vintage Mullard EL84's in it without rebiasing the amp.

    Today, it started to cut out and then poof, bad burning smell and it died.

    I took the Mullards out and put the old tubes back in, reset the breaker and fired it up. It lights up and then pops the breaker.


    What have I done?
     
  10. SamBooka

    SamBooka Member

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    Standard disclaimer. Even unplugged these things hold lethal voltages. If you know what you are doing they are very easy to repair. If you DONT know what you are doing they are even EASIER to repair. Take it to your tech.

    If you do know the hot end of a soldering iron these amps are easy to open.
    4 screws on the top. The chassis stays in the amp. The top pops off (and should have a schematic inside). Brilliant huh?

    Now use your eyes and nose (and nothign else) Look for burned components. Smell your components. If you dont see or smell what burnt try bringing it up with the power tubes out. If it blows a fuse it it probably your power transformer or maybe filter caps.

    Tune in next week to find out what it could be if it only blows fuses when the power tubes are in.
     
  11. doctorx

    doctorx Member

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    The top on a YGM3 doesn't pop off, you have to pull the chassis.
     
  12. bunuel

    bunuel Member

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    Several years' models of the YGM-3 do have tops that come off, they're ca. '72-73 models, as I recall. P. Traynor was constantly trying to improve the amps & he did. The top removal feature leaving the chassis in place with easy access for maintenance was a stroke of genius. Every amp should be so built.
     
  13. SamBooka

    SamBooka Member

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    I know the first ones didnt have pop tops. The reissues are copies of the first ones (for the cabs at least). I have a 71 ygm-4 (same amp but with 4X8 speakers). It is a pop top.
     

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