Old design

[markyu]

Those were the times!!!
I 'v been designing and making amps, preamps, speakers, and a lot of audio related stuffs, in 90's. I was young B.D. in EE then and I loved making and tweaking audio equipment for pubs and clubs.

I am in comp and net buissnes now with no time for DIY. Yesterday I was listening to my 16 years old amp design and it sounds still impressive, much better then my neighbour's new Yamaha A-S500. Ok Yamaha has so good design and remote but ...
I decided to post links to some old pages.
Here is amp: P400 characteristic
Some notes: http://www.ptt.rs/korisnici/s/r/srmarkovic/P400Tips.txt
Zipped files : http://www.ptt.rs/korisnici/s/r/srmarkovic/p400.zip

Ty for reading my post.

[sakis]

thanks for sharing but your calculations about 380 Wat 8R per chanel with 2 pairs of transistors and 65+65 volt rails are obviously very wrong .... not to mentrion the comment 2-16 ohms since at 65 +65 rails with only 2pairs of tranistors is simply not possible ..... it could work but the VI limmiter will not allow the amplifier to poroduce any usable power ...

[markyu]

Originally Posted by sakis

thanks for sharing but your calculations about 380 Wat 8R per chanel with 2 pairs of transistors and 65+65 volt rails are obviously very wrong .... not to mentrion the comment 2-16 ohms since at 65 +65 rails with only 2pairs of tranistors is simply not possible ..... it could work but the VI limmiter will not allow the amplifier to poroduce any usable power ...

Well you are right. But one of the first amps which is still in use in my home cinema has about 76+76 volts rails and actually I made all measurments with this one (I made more than 20 amps with same pcbs but various power supplies) . I had great russian 1.8KW 55+55v AC transformer so I made amp with this transformer. I had problems with too high voltage and burned 10 or more Motorola MJ 15004 MJ 15003 during tests but finally put good transistors which are still on heatsinks.
I used Tektronix tds210 for measurements and tests and somewhere I have pictures of sine and square signals made in 1996.

This amp has been working on 4 ohms speakers in one pub for years. When friend closed this pub he returned me amp, preamp and an old CD player a few years ago. I changed a few cap., main protect reley and terminals so this amp is still in use.