A very simple power amplifier circuit built with 741, 2N3053, 2N4037, 2N3055 and MJ2955 which deliver up to 50W on a 8Ω speaker.
If you want to amplify lower frequencies increase the 4.7uF capacitor from the audio input or decrease it if you want to favour higher frequencies.
Use a 3A symmetric power supply for mono application and a 5A for stereo power amplifiers. Please take good precaution when use this audio amplifier : do not shortcircuit the output or not connect speakers ! Always check twice ! continue reading…

TDA 2030 is produced by SGS Ates and is a complete audio amplifier. AB class of the final amplifier cand deliver up to 14W on 4 ohm at a +-14V power supply.
Connecting two TDA2030 thru cheap power transistors we can create a amplifier wich can deliver a higher power. With the components value from the schematic the total amplifier gain is 32 dB. The speaker can be 2 ohm instead of 4 ohm if we use the TIP transistors. With a proper designed power supply this audio amplifier can output 200W. continue reading…

TDA7560 is a 4 x 45W QUAD BRIDGE CAR RADIO AMPLIFIER PLUS HSD.
The TDA7560’s inputs are ground-compatible and can stand very high input signals (± 8Vpk) without any performances degradation. If the standard value for the input capacitors (0.1mF) is adopted, the low frequency cut-off will amount to 16 Hz. continue reading…