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  • LM12 operational amplifier can output currents up to 10A. The LM12 in encapsulated in TO-3 with 4 pins, can support up to 800W and has enough internal protections to prevent slacks from over-currents or over-heating.

    You can use LM12CL with 30 V maximum voltage or LM12C with 40V maximum.
    The L1 coil has 40 turns 1mm copper, coiled over R4. If you use LM12CL it is recomended to have toroidal transformer 2 x 22V. The output must be between 7 and 12A. Filtering capacitors must have at least 20.000 uF.
    LM12 must be mounted with screws on a big heatsink (=< 1.50 C/W) and electric isolated form the heatsink

    LM12 amplifier circuit diagram

    lm12 150w audio amplifier circuit diagram

    LM12 amplifier PCB layout

    lm12 150w pcb layout

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    12 Responses to "LM12 150W Audio Amplifier"

    1. for project,thanks

      • I’ve got about 60 Genuine National Semiconductor LM12CLK’s that were used in a high end subwoofer amp back in the 90′s
        We changed the design and a bunch of these IC’s ended up in my garage. I totlaay forgot about them for about ten years.

        They are selling for around $35.00 each on ebay now and I was planning on listing mine. If you are interrested you can have as many as you want for $20.00 each

        I’ve also got some Motorola MJ11013 and MJ11014 Complimentary Darlington Transitors that were used as a final output stage to boost the power. I think the amp was rated at around 250watts. Sorry no schematic of the old amp.

      • Hi,
        do you still have the LM12s available? I just blew a pair of thesed from my audio amp and would need replacements. Please let me know if they are still for sale.


      • I realize this post is several years old, but do you still have any LM12CLKs?

      • naseem hussain says: on May 18, 2013 at 1:53 pm


        I have LM12CLK in my stock , if you still need these , let me know your target price.

        thanks Naseem Hussain

    2. Alex Dusouza says: on January 11, 2010 at 9:45 am

      very much interested in the LM12 I,Cs.

      • Mario A. Scalia says: on July 14, 2010 at 7:35 pm

        Hola como estan.Vivo en gral.Roca Rio Negro Argentina estoy muy interesado en armar el amplificador de audio con el LM 12.Me encuentro con la dificultad de conseguir el mismo y sobre todo por el elevado precio que tiene en esta zona.Por favor necesitaria si me pueden dar direcciones o tel.de comercios de bs.as.que lo tengan. desde ya muchas gracias.

    3. dj sapo says: on June 19, 2010 at 2:55 pm

      gracias a favoritos….lo armo y comento

    4. Jonathan says: on October 2, 2010 at 3:53 am

      donde concha se consigue ese lm 12 XD vivo en colombia y no e podido encontrar ese integrado

    5. hi dave,
      do you still have lm12 clk for sale

    6. Peter Jordi says: on September 8, 2013 at 1:24 am

      I would like to buy 3 pieces
      LM12 from you for 25CAD each.
      You doing that over Ebay?
      Kind regards Peter

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