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Amp (Transformer)

Discussion in 'Amps and Cabs [BG]' started by Angel LaHash, Jan 10, 2013.

  1. Angel LaHash

    Angel LaHash

    Aug 24, 2012
    Apart from shock going up my arms.. derrrr

    Right i got a bigish AMP, the guy did think the Transformer wasnt working.. i hooked a Meter over each leg to see they are still linked and they are "continuity". So powered it up and tried to get a reading.. i could see the Power light was on
    Well got a bit of a shock and the meter buzzed a bit but still alive..
    I couldnt read any thing really on the Meter

    Just thinking of it, i had it in DC!! ahh
    but also when i went to do a resistance between 2 legs on the secondary side i got 1Ohm! do you think its shorted out some were to get such a low reading
  2. B-string

    B-string Supporting Member

    If it was shorted the fuse would have blown, if the fuse is bypassed it would have smoked.
    You need to to check for AC voltage at the secondary if your meter is not already damaged. Are you sure you are safe to be doing this?
  3. Vostre Roy

    Vostre Roy

    Mar 22, 2012
    This. Amp has enough voltage to be deadly, unless you know exactly what you are doing, never play inside an amp.
  4. Angel LaHash

    Angel LaHash

    Aug 24, 2012
    I only do Electrical Installations.. and used to be a Design Tech
    but i normaly dont work with Transformers

    also when its someone else i can think but when its my own i want to talk about it more to make sure for some reason like i dout myself

    I just forgot the AC Voltage as I been in DC a lot of the time.. No Fuse was blown tho
    and as for me getting shocks, i seem to live pass Direct Mains to the Heart.. Touching a buzz bar while on .. and been shocked in the Shower
  5. wcriley


    Apr 5, 2010
    Western PA
    There's a big difference between getting bitten by 120v AC and getting hit by the 400v to 700v DC that is common in tube amps.
  6. tom-g


    Oct 2, 2007

    Take it to tech.

    By the way, the secondary of transformer is basically a wire coil. Now you tell me what the reading of your ohm meter should read. You can't check if transformer is ok that way. Well, unless it's infinity, then it's broke.
  7. B-string

    B-string Supporting Member

    Buzzing in a test meter is a bad thing, it usually means you have exceeded design values for arc-over. You meter needs to be rated for at least 1 KV AC.
    Why are you starting at the transformer first if the fuse is not blowing?
  8. Angel LaHash

    Angel LaHash

    Aug 24, 2012
    No Tube in it and its a bit from 240v 80mA as it was the buzz bar
  9. Angel LaHash

    Angel LaHash

    Aug 24, 2012
    well a Pick up is a load of wires and it ranges from 4k-20kOHMS
    so i would personal expect a bit more than that
  10. Angel LaHash

    Angel LaHash

    Aug 24, 2012
    i did check the wire from the Socket to the Transformer
    Transformer to the board
    and the Fuse ..

    check the transformer than there is a flow going in the Prim
    and a flow can be hand on the secondary

    So as i see its all working.. BUT if there is a short in the transformer i guess it will skip some of the coils making the transfer rate highter
  11. B-string

    B-string Supporting Member

    The resistance of a power transformer is pretty low. The number of wire turns and gauge of wire is radically different from pickups.
  12. wcriley


    Apr 5, 2010
    Western PA
    Oops. I saw "biggish amp" and "transformer" and automatically read "tube". Sorry 'bout that.
  13. B-string

    B-string Supporting Member

    What? Shorts in a transformer usually will burn through the separating insulator and cause over-current.
  14. Bassmec


    May 9, 2008
    Ipswich UK
    Proprietor Springvale Studios
    The only way to test the performance of an output transformer that isn't obviously open circuit and therefore obviously dead is to use a heater transformer powered by a Variac to supply a very small voltage to the secondary and measure the primary voltage at the tube sockets.
    Take this amp to a good tech as its probably a case of a little knowledge being a very dangerous thing.
    You got a shock from the AC you won't be doing anything but smoking ever so slightly if you get across the DC ht if its got any working diodes in it.:bassist:
    Sorry just read its a transistor amp of some as yet un ascertained description:spit: best put it in the garbage then, as they are not worth messing with, when you can buy one that works and weighs nothing for about 30pence and a half chewed mars bar these days.:D
  15. B-string

    B-string Supporting Member

    We are apparently talking about a SS amp.
    IF the secondary had inter-wind shorts (isolated from chassis or primary) the secondary voltage would be lower, resistance still means very little unless it is a complete open. You need to measure AC voltage at the secondary and compare to the spec on the schematic.
  16. BassmanPaul

    BassmanPaul Inactive

    This whole thread has filled me with alarm. OP PLEASE take the amp to a tech. His bill will be much less than your life is worth!!!!
  17. BawanaRik


    Mar 6, 2012
    New Jersey
    +1 I would buy a Aspen Pittmann Tube Amp Book or Gerald Weber's, Handbook.

    And Keep your left hand in your pocket. When and trust me it's when, you do get that potential life ending jolt you don't want your heart in line.

    I got hit with a TV high voltage and survived.
  18. Angel LaHash

    Angel LaHash

    Aug 24, 2012
    well i was told i would die by 17 of CF and lived pass that
    Had Strange Heart Flutters as 12 due to a Mains
    Sent to a Hospital with a Child Killer
    Touched the Buzz bar..
    Touched a Transformer in a PVR at work one time (smelt funny all day)
    and just got a little Jolt off off a AMP what just made my arm feel funny

    Why else am i called Angel.. also seem to have a Low Resistance and a High Salt level
  19. Angel LaHash

    Angel LaHash

    Aug 24, 2012
    Is a Tube Amp but just one ECC83 (think its 83) i got to buy one but i kind of hoped that i could get it running before spending money on a Tube .. them dam things cost £10 a pop 12AX7
  20. Bassmec


    May 9, 2008
    Ipswich UK
    Proprietor Springvale Studios
    That's about par for the course around here, I have Aspergers and dyslexia, can't you just borrow a known good ecc83 for test purposes.
    Is there any information on the amplifier, like make or type, or anything else us amplifier OCD junkies can get our teeth into.:bassist:
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