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Solarus --no output

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  • Solarus --no output

    ive got a 69 Solarus here . Just installed all the correct tubes , this one is the el34 / 7199 version .
    I have no output ...when probing the el34s , pins 3 and 4...i can barely hear a little noise..with Volume on 10....where normally you can hear a fairly loud pop or noise . Ive double checked the wiring of the 7199 .

    swapped out the 1st 2 pre tubes

    All voltages are perfect everywhere including bias. Ive probed the entire amp with a plastic chopstick , moved every wire , cant see anything burnt or damaged .

    Starting to think it might be the OT ?? Is there anything else to look for on these old Sunns ??

  • #2
    Got a schematic?

    Edit: Is it this one?

    http://www.prowessamplifiers.com/sch...arus_EL34.html
    "Yeah, well, you know, that's just, like, your opinion, man."

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    • #3
      yes---sorry forgot the scem

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      • #4
        Check the speaker AND wiring for function.
        Education is what you're left with after you have forgotten what you have learned.

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        • #5
          Do you have a scope? If so use that, if not use a DVM set for AC volts and trace signal through the amp.
          "Yeah, well, you know, that's just, like, your opinion, man."

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          • #6
            no scope

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            • #7
              ok---so i ran a test tone into the input about 2k . Checking with AC meter i start at 13vac at the 1st 12ax7 and it ramps up each stage , and i get up to 55 - 60 vac at the outputs of the 7199 , that head to the el34s . Sound about right ?

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              • #8
                13V input is really hefty, so I suppose 55-60V at the PI out is reasonable. At any rate, you have signal there and no output, so the problem is in the output section. You said, "All voltages are perfect everywhere including bias", so I presume plate and screen voltages are there? Check signal right at the output tube grids just to make sure it's getting there. If so, I'd do some quick resistance checks on the OT.
                "Yeah, well, you know, that's just, like, your opinion, man."

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                • #9
                  yes---every reading is great--according to that scem . ill check the el34 grids ---thanks

                  i think i saw 13v out of the 1st 12ax7

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                  • #10
                    Have about 50vac to the el34 grids

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                    • #11
                      That's really hot. You might want to back down your generator. You should see about 1/10th that at the V1 plate.

                      Edit: Sorry, I was typing during your last post. This is in response to post #9.
                      "Yeah, well, you know, that's just, like, your opinion, man."

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                      • #12
                        I'd unhook the yellow and orange taps from the OT secondary and hook a speaker directly to one of them to eliminate a possible jack or jack wiring issue.
                        "Yeah, well, you know, that's just, like, your opinion, man."

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                        • #13
                          Originally posted by The Dude View Post
                          I'd unhook the yellow and orange taps from the OT secondary and hook a speaker directly to one of them to eliminate a possible jack or jack wiring issue.
                          tried that---nothing

                          the 1k/ 2w and 680 ohm/2w are good ---right by the OT in the scem

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                          • #14
                            Sadly, this is looking like a bad OT. Check primary and secondary resistances and see if you can spot an obvious failure- i.e. open winding, etc. If it is the OT, it's not going to be cheap since this is an ultra-linear amp. It would probably be cheaper to reconfigure/modify the circuit and use something more standard.
                            "Yeah, well, you know, that's just, like, your opinion, man."

                            Comment


                            • #15
                              Originally posted by The Dude View Post
                              Sadly, this is looking like a bad OT. Check primary and secondary resistances and see if you can spot an obvious failure- i.e. open winding, etc. If it is the OT, it's not going to be cheap since this is an ultra-linear amp. It would probably be cheaper to reconfigure/modify the circuit and use something more standard.
                              thanks-- i dont know if i want to go that route . I think the Dynaco replacements are $140 ?

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