Elias from Cyprus upgraded his 303 with the Dada kit.
The parts were received in no time after placing my order and straight away I got down to work. I came across some difficulties but these were very quickly resolved by emailing DADA electronics. I must here thank these very courteous people for their so quick service.
After completing the work I calibrated the voltage and quiescent currents and connected the QUAD 303 to my hi-fi system. And what a surprise! It now sounds a much better amplifier than before. I can imagine how much better it would have been had I replaced the amplifier and power supply boards with their high end ones. One day I will do it. But before that I will upgrade my Quad 405, hopefully with DADA's 405 high end boards, BHC Aerovox dual mono power supply unit and loudspeaker protection units."