Mine quality power amplifier stable 2 ohms

[DjLeco]

Having lasts 10 pairs of original's TOSHIBA 2SA1943 and 2SC5200, I decided to put'em on work and made an amplifier for high freqvency drivers or speakers, more in parralel.

The amplifier is fully capable driving 2 ohms loading, all the time.

Power around 140 watts on 8 ohms, 250 watts on 4 ohms and 420Watts on 2 ohms x2 channels.

The amplifier have 2x56Vcc idle, @ 230 volts , 1,5 sec softstart delay, noise filter TDK 2x15A, against pop and noises from network power supply , protection against shortcircuit at output, it action at 1,5 ohm dummy load, and thermal protection at 100 celsius degrees, wich cuts down primary trafo power supply, letting only 12Vcc for FAN and command ciscuits from separately 12 volts 1A supply.
Output devices are 5 pairs 2SC5200 & 2SA1943 each ch (5/rail), prefinals are NJW0281 & NJW0302 with BD441 superdiode.

All components used are high quality for a high quality product !

OFFSET-UL are under 5 mv/each output.

During tests, soket supply was around 221 volts, dropping low till 214 volts, primary transformer was made for 230 volts.

Pictures during construction:






























Movies during tests, choose 720p on youtube:


Intro:

http://www.youtube.com/watch?v=vhXnY78sBeA



Testing on 8 ohm dummy load:

http://www.youtube.com/watch?v=CQujXEi0AqY



Testing on 4 and 2 ohm dummy load:

http://www.youtube.com/watch?v=CR_Mt2dM1GA

http://www.youtube.com/watch?v=d-L6v1t6wXE



Testing 2x4 ohm dummy load:

http://www.youtube.com/watch?v=8kpcbfJPxDM

Offset measurement:

http://www.youtube.com/watch?v=9k3R0wUUk08



Testing on speakers with audio signal on 1,5-1,6 ohm load:



http://www.youtube.com/watch?v=HXBQ9dT4jkw

http://www.youtube.com/watch?v=JUkLWhtlGHU

http://www.youtube.com/watch?v=BJylldj61Fk


Pay more attention from here:


http://www.youtube.com/watch?v=ObgqAqm5DdE

http://www.youtube.com/watch?v=yMVy19JaBUY

http://www.youtube.com/watch?v=ojjVENKIuuM

http://www.youtube.com/watch?v=pqPobUJQBGg


Quality audio

http://www.youtube.com/watch?v=mUiDzISZVaY