ABOX 40W Power amplifier with very low TIM distortion

In 1982, the Polish journal ‘Radioelektronik’ published an article about this amplifier with subsequent updates - it is called ABOX on the Internet.

In 1994, I made this amplifier as my thesis for graduation to electronics technician and now, after almost 30 years, I took it out of the garage, replaced the electrolytic capacitors, started it and ... it worked quite well.

Continuing the fun, I designed a new PCB inspired by the above-mentioned article and made anew with brand new components and again - it worked well.

I encourage everyone, even a beginner in electronics, to play with this design. Please have look at preview films on the film portal:

nominal input voltage 40W / 8Ohm - 0.775V

input resistance - 47kOhm

frequency response (-0.5 dB) 10Hz ... 20kHz

Nonlinear distortions h (%)

 35W - 0,005 - 0,0025 - 0,005 - 0,007 

 20W - 0,005 - 0,0025 - 0,004 - 0,0055 

 10W - 0,005 - 0,002 - 0,004 - 0,006

 01W - 0,006 - 0,0025 - 0,005 - 0,007

0,1W - 0,0075 - 0,0075 - 0,0075 - 0,0075

  f - 100Hz - 1kHz  - 10 kHz - 20 kHz