Quad 33 control amplifier disc adaptor cover for use with phono plugs

thingiverse

The Quad 33 control amplifier (preamp) was designed in the 1960s, but it's not out-dated. It still does precisely what a stereo preamplifier should do. However, the phono preamp part of the amplifier is a bit limited in that it is suitable only for moving magnet cartridges. For me, though, the biggest problem is that due to the arrangement of my hifi, my record player is several metres from the Quad 33. This means extra long cables, more capacitance and dulled treble as a result. I therefore want to use my extrenal phono preamp near to the record player and run most robust line level signals into the Quad. Quad published a sheet of information in the 1990s which covered how to adapt the phono preamp to accept line level inputs, but this kept all the circuitry in use even though it made it close to a unity buffer. There's no need to do that. I've removed the Quad preamplifier from the circuit altogether as its simply not necessary when a line level input is required. See this webpage for more details: http://www.hembrow.eu/personal/quad33-303.html#phonomod