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No matter how you spell it or pronounce it, they can be quite useful - with some modifications and routine maintenance. Just a note that the model 2020A that you find is not the same as the 2020A+.... Enjoy!
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12 thoughts on “Weird but practical – leper amps!”
  1. Avataaar/Circle Created with python_avatars Matheus Moreira says:

    Hi Fran, if you want help rolling your own class-d amp, that should last you decades of a very service-friendly life, I'd be delighted to help! I've just the topology for you. ≤0.05% THD, ≥95% efficiency should be in order, right?! Get in touch!

  2. Avataaar/Circle Created with python_avatars UpLateGeek says:

    Yeah, those switches are designed for switching AC current, not DC. I struggled to find a switch that was rated to switch a decent DC current for a project, because I needed a right-angle PCB mount switch.

    I'd also look at adding an RC snubber across the switch. Even if the output is muted when it's switched on, the thump still happens, so that could help reduce the spike in power through the amp. I read it helps reduce arcing when breaking high-current loads, so I'm looking at adding one to my project since it would be running in the 2-6A range most of the time.

  3. Avataaar/Circle Created with python_avatars Hola! David Perkins says:

    Maybe that newer design dissipates WAY less power than the previous one. I tend to doubt it though.

  4. Avataaar/Circle Created with python_avatars T B says:

    It looks like Parts Express has those Lepai 2020 amps in stock. I just visited their showroom last week. Pretty cool place; the two guys working there were friendly and helpful. Lots of stuff to look at.

  5. Avataaar/Circle Created with python_avatars Bacon Sanderson says:

    We've got a 20 watt class-D mono amp board we make at work that doesn't have a heat sink. There's some via stitching to dissipate the heat into the ground plane, and that's all the manufacturer of the chip recommends.

  6. Avataaar/Circle Created with python_avatars skip trailer says:

    Had to tell someone?

  7. Avataaar/Circle Created with python_avatars Vaughan McKenzie says:

    this is perfect for my needs, the switch and controls will not be touched often and it will be powered on from the same switch as the streaming equipment. Our need for this is as an output from the mixer to the input of the streaming equipment so we can get decent volumes as currently the ambient mic and input from mixer are maxed in software and its still not loud enough.
    How much do these cost and where can I get 1 of the older 1s with the big chip?

  8. Avataaar/Circle Created with python_avatars Roman Charak says:

    If the quality is so poor, why now rebuild the circuit on a new board, in the original case?

  9. Avataaar/Circle Created with python_avatars CuriousMarc says:

    It’s a Leperchaun amp 😉

  10. Avataaar/Circle Created with python_avatars Christian Holmstedt says:

    Why do you call them 'Leper' amps?

  11. Avataaar/Circle Created with python_avatars William Grout says:

    I have used several of these "original" amps for many years and have been very impressed with the build quality and longevity for the price point. Most of them came with a minimal power supply and will do much better with more amps in.

  12. Avataaar/Circle Created with python_avatars The Buffalo Estate says:

    Gosh I wish I still had mine now I know what the problem with it was! Mine did the same motor boating after a while. ❤ great video

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