NEW OLD STOCK...Should I worry?

Discussion in 'DIY' started by z-adamson, Jun 26, 2018.

  1. Tim64

    Tim64 Super Member

    Messages:
    1,074
    Location:
    North Central West Coast
    Ditto here it chops the ac wave form, a friend of mine way back blew up his receiver using a dimmer control.
     
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  2. Scott75s1974

    Scott75s1974 Member

    Messages:
    94
    Just a question, not a confident suggestion. A dimmer won't work as a jury rigged variac for the reasons cited. But could one use the secondary from a spare amp/receiver that would provide say 60 or 80 VAC? It wouldn't work for careful dialing up. But could it allow some soaking time to reform capacitors?
     
  3. z-adamson

    z-adamson AK Subscriber Subscriber

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    1,448
    Got these preamps in my hands and I have been running them on a 25w bulb for a while now.

    Date of manufacture is a bit older than I thought. They are from 2002.

    Anyhow, bulb stays dim on all of them.

    So, I ran them on the bulb for about 12 hours then wall power for about 12 hours. I took the tops off and looked around inside. Nothing odd. No swollen caps or anything. Heatsink mounted transistors get warm as they should.

    Should I call them good?

    I have not yet run audio through them.
     
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  4. OMGCat!

    OMGCat! AK Subscriber Subscriber

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    2,787
    Location:
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    I'd have no concerns about using them after running for that length of time. Sounds like they're ready for a proper test in your system.
     
  5. petehall347

    petehall347 the brandy coffee man Subscriber

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    26,188
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    uk.. the middle bit
    give them a try for sure
     

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