Power Transformer

Discussion in 'The Workbench' started by Hollowbody, Nov 5, 2011.

  1. mickeydg5

    mickeydg5 Well-Known Member

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    The GZ34 is a nice rect tube and is indirectly heated. It however has the least sag. For amps with a choke or resistor, if you use a resistor instead of the choke in your B+ rail, the amp will have even less sag. The 5e3 design doesn't have that.

    Just something to keep in mind.
     
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  2. Ken

    Ken Well-Known Member

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    +1000

    You have to start somewhere! I started by poking around my amp with a meter to find out why it died a few times. I knew the basic safety precautions so off I went! I've now fixed my amp 3 times (with tons of help from here) and I'm gaining confidence to do new things like measure tube voltages and such.

    You sound like me: a rational guy who understands what amps are about, and stretching your envelope. I know we all say, "This can kill you" but that's advice for idiots, not rational owners who have the interest to be more hands on and do their homework. Like asking questions of the group here!

    Stay at it!

    Ken
     
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  3. Joey Voltage

    Joey Voltage Well-Known Member

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    Huh? Man, I don't see no paraphrase inverter in that link, I just see a self split push pull output section. There is no dedicated phase inverter block in the link hollowbody posted the output stage is functioning both tasks.

    The reason you dont see it used often is because that it is horribly inefficient, and many would consider it a waste of otherwise available output power especially for consumer electronics. However this is a DIY guitar amp, which isnt necessarily concerned with trying to juice as much as possible out of as few devices as possible.

    You see that self split pp stage used a bit in the DIY community.
     
  4. TradAmpGuy

    TradAmpGuy New Member

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    Self split in a Firefly sounds killer... all .5 watts of it :dude:
     
  5. Joey Voltage

    Joey Voltage Well-Known Member

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    Yeah and probably still too loud for a bedroom
     
  6. mickeydg5

    mickeydg5 Well-Known Member

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    You busted me!:)
    Damn. When I was writing that I was actually thinking long-tailed. I do not know why I put paraphase. Yes the circuit and the tubes are doing both jobs - but no actual driver. I think I read somewhere low efficiency/low power. I was also thinking probably unstable especially with high gain.
     
  7. Joey Voltage

    Joey Voltage Well-Known Member

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    WTF! Mickey, I'm not the amp police ;)
     
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  8. mickeydg5

    mickeydg5 Well-Known Member

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    The amp police, they want to look inside of my head
    The amp police, they won't stop till I am dead
    The amp police, they are coming to arrest me
    oh no!

    :naughty::):lol:
     
  9. Hollowbody

    Hollowbody Well-Known Member

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    I would expect less power in this case but how would it be less stable?
     
  10. Joey Voltage

    Joey Voltage Well-Known Member

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    Nah, I will be as unstable and as unbalanced as you choose it to be, just like any other output stage topology. Also don't let the horrible inefficiency reputation turn you off either, depending on what bottles, speakers, and design parameters you use, you could make an amp that uses sppp able to hang with a loud drummer (higher wattage and efficiency doesn't necessarily mean louder).... Although that might defeat the point.

    Alright enough from me maybe I will check in next week.
     
  11. MajorNut1967

    MajorNut1967 New Member

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    lol
     
  12. TradAmpGuy

    TradAmpGuy New Member

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    Yeah, a bit. Built one for my brother and it kills with a pair of greenbacks. Hes already gotten the mod bug on it and swapped out some caps to tweak the high gain tone to his liking. Fun build and a blast to play, I would highly recommend one.
     
  13. mickeydg5

    mickeydg5 Well-Known Member

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    So the little monkey (Firefly) can jam. Does he push it with anything?

    I listened to the sample and it sounded kind of raw. Maybe it was just the recording.
     

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