Simple Two Way Amplifier For Microphone And Guitars

Fig. 2: PCB layout of the simple two channel amplifier for one microphone and two guitars
Fig. 3: Component layout of the PCB

Download PCB and component layout PDFs: Click here

The loudspeakers can be 4-ohm to 16-ohm, peak-output current can go up to 3A or even 5A in some cases, and peak-output power is from 10W to more than 40W, depending on the selected ICs, heat-sinks, power supply and configuration of output (dual-way or bridged amplifier).

This power amplifier usually does not need any adjustment, but it is important to have the gains of the output stages as mentioned earlier. For troubleshooting, check voltages at various test points listed in Table II.

Petre Tzv Petrov was a researcher and assistant professor in Technical University of Sofia (Bulgaria) and expert-lecturer in OFPPT(Casablance), Kingdom of Morocco. Now he is working as an electronics engineer in the private sector in Bulgaria.


  1. Hi! Thank you for posting this project online. I plan to use it in my class. We will be building a PCB. May I please get the parts list? – AVV

  2. Thanks for this simple project..but please mention the advantages and disadvantages ..because it is very helpful l to the us….

    • Lm1875, Tda2030A, TDA2040, TDA2050 etc is giving 6 watts @ 4 ohms load on 24 volts 2 ampere supply even after using large heatsink. So I expect a maximum of 10 watts on 30 volts with the same load. However, it may output more power on split supply than on single supply

  3. How can I use this circuit to connect three Microphones and one usb mp3 module with all four sources working simultaneously ?


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