50 Watt Hi-Fi Audio Power Amplifier Kit – K106
This kit is based on an amazing IC amplifier module from ST Electronics, the TDA7294. It 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. 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.
(± 35V D.C. power supply)
Output power : > 50W RMS, 4-8 Ω load
~ 80W into 4Ω max.
~ 60W into 8Ω max.
Gain 24 dB (30dB modification)
Input sensitivity : 1.3V for 50W, 8 ohm
0.9V for 50W, 4 ohm
(0.6V, 50W, 8Ω, G=30dB)
Input impedance : 10kΩ
Signal-to-Noise ratio : > 95 dB, (>105 dBA)
Frequency response : ~ 20Hz – 200kHz, –3 dB
Slew rate : > 10V/uS
THD : < 0.01%, 1W-40W,1kHz
< 0.1%, at 50W, 20-20kHz
IMD : < 0.01%, 1W