DIY Portable HiFi Amplifier (2x30w, Class AB)




Posted in TechnologyAudio

Introduction: DIY Portable HiFi Amplifier (2x30w, Class AB)

About: Hi I'm Angelo! I am a 18 y/o college sophomore taking my majors in BS-ECE at the DLSU. I use my course as an inspiration for making my current projects! I've been posting projects ever since I was 10, and I'...

I've made a portable amplifier that uses a TDA7394 as its main IC chip. It's a Class-T amplifier look alike. There's also a hidden (internal) tone control circuit built with it. I posted it to inspire most of the people who asks me about making a "Class-T" amplifier, so I thought of making a Class AB-A amplifier instead. A Class AB amplifier has a fully symmetrical structure, this mean the sine waves (electric pulses) produces a + and - output.

Too bad I had a late documentation, that's why I only have a few pictures of the steps and procedures. If I make another one, I'l promise to fully document my amplifier as a step-by-step instructable.

My version works well with any wall wart, with a rating of: 12-28 volts, 1-5 Amperes, Switching-Transformer type.
I've also provided a schematic diagram of the amplifier. 

I hope you like it !



    • Casting Contest

      Casting Contest
    • Woodworking Contest

      Woodworking Contest
    • Make it Move Contest

      Make it Move Contest

    We have a be nice policy.
    Please be positive and constructive.




    E-X-C-E-L-L-E-N-T Project.....

    Very well done! I will definitely plan on building this someday.


    in the schematic i found 1.5M resistor but it was not in the parts list.
    checking the material bill against the schematic, it seemed like this is the 1.5K resistor. am i correct?

    2 replies

    Oh, its just a typo, you should follow the 1.5M

    Actually, the schematic and PCB it is also a capacitor 100uF / 25V, and in the parts list there is not ;).

    can I use it as guitar amplifier

    I'm working at this project. After i'll finish, i will attach some necessary images.

    hi, just wondering if that's 2x30w RMS or peak?

    i have 2 speakers of my father's stereo system
    i dont know its wattage

    What is exact size of the PCB you used?

    But do you know any international sites, where people like me can buy amp chips and so on?

    1 reply

    If your looking for robotic parts, go to , If you are living in america radioshack is a popular electronic store (although has incomplete retail products). If you want anything related about speakers and amps .

    So where do you buy amp chips and all the other things you need too build a amp?

    1 reply

    Luckily, most of the parts are available in local electronics stores here in the Philippines (such as: Deeco, E-gizmo, Alexan, RAON), they're cheap too! From Resistors, Capacitors, Transistors, I.C.s to Heatsinks, they serve a variety of products even kits. Everything that you imagine can be bought here in our country. Since we are near the manufacturing countries such as Taiwan, China, Japan, Singapore, Philippines (our country) everything on the pricelist is cheap!

    What does the hole project cost, maybe you have guide to how you build it step by step?

    1 reply

    It costs less than P1,000.00 ($20). I actually had an incomplete documentation with this project of mine, I will have to make another one of these again to take a full cover of the DIY amp.

    thank very nice, but don't you have a list of all the materials?

    1 reply

    It's stated from the image above, it's a bit small :)))

    please do another soon plus instuctable. i have seen your gainclone power amp but i wanna c a similar amp with volume control much like this. :)

    1 reply

    If you are planning to build an amplifier with a volume control, you could just add a pontentiometer, the left end of it should be connected to the input, the center should be connected to your output (amplifier-input), and the right end should be connected to your common ground.