Quick & dirty audio amp

Discussion in 'The Projects Forum' started by Experimentonomen, Feb 24, 2012.

  1. Experimentonomen

    Thread Starter Member

    Feb 16, 2011
    331
    46
    Heres a quick & dirty amp i threw together with parts from disassambled and scrapped projects. The SOA of the TIP35/36C transistors is just laugable, so just for the heck of it i took all the TIP35/36C's i had and put them all in parallel, which ended up at 5 pairs.

    Thus this is a piece of crap amplifier that sounds bad so i dont care if i blow it up.:p

    Pics:
    http://i.imgur.com/zHLaX.jpg
    Wired up:
    http://i.imgur.com/TyFk5.jpg
    http://i.imgur.com/TID78.jpg

    And finally, a video:
    http://www.youtube.com/watch?v=Un_AzGz5vGo
     
  2. Experimentonomen

    Thread Starter Member

    Feb 16, 2011
    331
    46
    and 361W RMS(722WPK) 38VAC 50Hz into 2 ohms later its dead. One of each type of the output transistors failed due to exceeding SOA, the remaining 4 sets are still alive but for safety reasons im gonna can them all, i have no use for these wimpy transistors anyways.
     
  3. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    38V RMS into 2 ohms makes a power of 722W which is 1444W peak power.

    The "music power" peaks of the music are probably higher.
     
  4. Experimentonomen

    Thread Starter Member

    Feb 16, 2011
    331
    46
    38VAC = 38V peak, around 19 volts rms. Atleast the peak of the waveform was at around 38V on the scope.
     
  5. Audioguru

    New Member

    Dec 20, 2007
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    896
    38V peak is 38V x 0.707= 26.9V RMS, not 19V RMS.
    If your 'scope showed 38V p-p then it is 19V peak which is 19V x 0.707= 13.4V RMS.
     
  6. Experimentonomen

    Thread Starter Member

    Feb 16, 2011
    331
    46
    I meant 38V peak swing each way from zero.

    Heres a new one with beefier transistors, a SOA of 4A at 50V each, compared with 1A at 50V for the TIP35/36.

    That drive board is not the right one for the project but good enough for testing.

    http://i.imgur.com/felhh.jpg

    And a short video, scope is set to 10V/Div: http://www.youtube.com/watch?v=S4l8xhctHF4
     
  7. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    Your numbers are meaningless. You don't know what are RMS, peak or peak-to-peak voltages so I will not talk to you anymore.
     
  8. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,392
    1,606
    Got schematic?
     
  9. Experimentonomen

    Thread Starter Member

    Feb 16, 2011
    331
    46
    No i don't, everything regarding amp design have since 3 days been lost in a hdd crash.

    Only schematics available is what is already posted in this thread.

    And yes i know what rms, peak and peak to peak is, peak to peak = tip to tip of the since, peak is from zero volts to one tip of the sine and RMS is peak divided by 1.414.


    So peak-to-peak voltage was 76 volts, peak was 38 and rms was 26.8v.

    No need to be rude, but if thats the way you want it, i'll quit posting my projects here as well.
     
  10. Georacer

    Moderator

    Nov 25, 2009
    5,142
    1,266
    @ Experimentonomen

    Not one member is representative of AAC as a whole, except of the moderating team. Do not let your browsing experience be decided by the words of only one member, either they are pleasing or not.

    Please use AAC to your content and will, as long as you stay within the ToS (This isn't to say that you have broken any rule at all).
     
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