This is a great audio amplifier circuit based on single power IC TDA7294. TDA7294 is intended for use as a high quality audio class AB amplifier in hi-fi applications. It has very low noise and distortion, wide bandwidth and good output current capability, enabling it to supply high power into both 4Ω and 8Ω loads. It has both short circuit and thermal protection, so is quite robust.
Component part list:
R1_____________ 150R R2, R3, R5_____ 10K R4_____________ 680R R6_____________ 22K IC1____________ TDA 7294 Heatsink
C1____________ 1u5F or 1u C2____________ 2n7F C3, C6________ 22uF 63V C4, C5________ 10uF 63V C7, C9________ 2200uF 50V C8, C10_______ 100nF
With the addition of a handful of parts and a suitable power supply, this module will deliver over 50W RMS into 4 or 8 ohms with < 0.1% Total Harmonic Distortion (THD) and < 0.1% Intermodulation Distortion (IMD). A similar circuit was published in Elektor magazine, 11/96.
It is also suitable as a replacement power amp stage, or upgrade for many existing amplifiers of between 30W-50W, provided they have a suitable dual supply, and most do.
Download the explanation of this amplifier circuit in pdf format HERE