Quad 303 upgrade has now been added to the list of products on sale in the online shop - Our Quad 303 amplifiers undergo the following improvements: 

o The transformers are revarnished.
o The main 63v and 100v 2000uF electrolytic capacitors are replaced using high quality
   uprated audio-grade components of 10000uF capacitance (Nippon Chemicon also called Nichicon)

o The chassis and components are cleaned.
o All printed circuit boards are cleaned of dust and grime.
o Amplifier boards have all the electrolytic capacitors replaced using
   uprated high quality audio-grade capacitors (Panasonic FJ, Nichicon and Elna Starget)

o Where components have expired due to old age or abnormal usage they are all replaced by modern
  uprated higher capacity versions.
o All connections checked and re-made where necessary.
o Exterior case cleaned
o New components on the PCB potted to hold them fast to the board ensuring no movement.