LM386 amp?

Discussion in 'Shock Brother's DIY Amps' started by Mark the Moose, Jul 23, 2019.

  1. Mark the Moose

    Mark the Moose Tele-Holic

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    Anybody try an LM386 build? I’m thinking a noisy cricket might be a good solution for a practice amp in my office. Pair it with a WGS Veteran 10...
     
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  2. boredguy6060

    boredguy6060 Poster Extraordinaire

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    There was something about LM386 a few years ago. I can’t help in how to search for it
    There was a schematic posted that I remember asking some questions about, but I don’t remember the name of the poster.
    Sorry couldn’t be more help.
     
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  3. D'tar

    D'tar Friend of Leo's

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    shortcircuit Tele-Meister

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    jvin248 Poster Extraordinaire

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  6. 8trackmind

    8trackmind Tele-Afflicted

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  7. PhredE

    PhredE Tele-Holic

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    Mark the Moose,

    I did something kind of/sort of analogous (strictly for 'practice'):

    I initially set out to build the LM386 based amp, but then looked around and decided to just buy an assembled amp module and see it I could just tweak things to make it work as a simple basic guitar amp. Well, I think I got something that does ok.

    I used ones built/sold by DROK and sold on Amazon. I had pretty good luck with the TDA7297 (I think it's 15W * 2 output) amp. I had to add a separate power supply and wire things together, but that's no big deal. Total cost for both was < $20 I believe. Portable as heck too (the power supply is about 1"x2.5"x4", the amp module itself is like 1"x1"x1.5"). Also, as a disclaimer, I can say the power ratings are VASTLY optimistic compared to what a guitar player would expect at the same nominal rating. Without preamp-ing your signal, it will sound lethargic and lifeless. I run it through a tube preamp, and either a Joyo AS or Joyo ACTone and it really sounds pretty good.

    Later, I decided to pick up a more powerful amp module based on the TDA7377 (nominally 35W * 2). The power demands were greater so I had to pair it with a new power supply. I think the physical layout and dimensions are very similar as the previous one though. I spent a few more bucks putting these things together to make it work (maybe $25 or so). Overall, cheap, compact flexible. You'll definitely want *something* in front of the amp to boost/hone/tweak signal level and EQ pattern though. On it's own, it just doesn't do the job.

    I doubt a link will work here, here are the product descriptions from Amazon:
    DROK TDA7297 15W+15W Audio Power Amplifier Module AC/DC 9-18V 2.0 Dual Channel Stereo Amp Board

    DROK Micro TDA7377 DC12V Digital Audio Power Amplifier 35W+35W

    ..FWIW.

    Update: Also, as an FYI, the Fender Champion 40 (and I think Champion 20) use the TDA7294 chip for the power amp. Similar, but not quite the same.
     
    Last edited: Jul 24, 2019
  8. Andy B

    Andy B Friend of Leo's Silver Supporter

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    Runoff Groove Ruby
     
  9. tubedood

    tubedood Tele-Meister

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    I 2nd (3rd?...4th?) the Ruby. It was a fun and informative, easy to grasp project.
     
  10. Zepfan

    Zepfan Poster Extraordinaire

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    I made a Ruby amp way back and it's really good.

    I built a Noisy Cricket amp, but wasn't impressed.

    Later I built a Dual Chip Bridged Amp that I based on the Ruby, Noisy Cricket and the Tufnel Distortion pedal by Beavis audio and put it all in a small cabinet with a 10" WGS Veteran speaker. The speaker had a bright tone to it in the Pine cabinet I made. The amp has a lot of distortion(probably too much), but not much volume for a 1 to 2 watt amp.
     

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  11. robrob

    robrob Poster Extraordinaire Ad Free Member

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  12. Mark the Moose

    Mark the Moose Tele-Holic

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    Ruby seems like a crazy simple build. Maybe I’ll box it up with a Timmy and a Belton Brick reverb to keep in my office for lunch hour noodling.
     
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  13. Zepfan

    Zepfan Poster Extraordinaire

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    Put the 47nf/.047uf input cap on a 2-way on/on switch with a .1uf cap on the other side to use for darker tone(known as the Bassman mod) and you can add a tone pot circuit off the volume as shown in my post earlier if wanted.
     
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  14. Zepfan

    Zepfan Poster Extraordinaire

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    I have used the Ruby as a preamp into a cheap 20watt Radio Shack PA for a couple of years. It works very well that way or I run it through a 6" speaker for bedroom volumes.
     
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