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 4 ohm and 8 ohm 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.
Power supply: +/- 35V DC
Specifications (35V D.C. power supply)
Output power : > 50W RMS, 4-8 ohm load
~ 80W into 4 ohm max.
~ 60W into 8 ohm max.
Gain 24 dB (30dB modification)
Input sensitivity :
1.3V for 50W, 8 ohm
0.9V for 50W, 4 ohm
(0.6V, 50W, 8 ohm, G=30dB)
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
Heat sink not included.
