Quad 303 amplifier Upgraded to Modern Audio Standards
This Quad 303 has been thoroughly overhauled using audio-grade components. This amplifier is an absolute classic!
The Quad 303 transistor amplifier was launched by Quad in the late nineteen-sixties to an advanced specification and design. It has gained the reputation as being the "God of all amplifiers" winning a Council of Industrial Design Award in 1969 and remaining in n production until the early eighties.
The Quad 303 was Quad’s first solid-state amplifier using use triplets in its output stage ensuring very low distortion whilst being "unconditionally stable at any load".
The upgrade using modern day components allow the unit to provide a level of performance that will certainly equal or surpass modern equipment costing much more.
o The transformer has been revarnished.
o The main 63v and 100v 2000uF electrolytic capacitors have been replaced using high quality uprated audio-grade components of 10000uF capacitance (Nippon Chemicon also called Nichicon)
o The chassis and components have been cleaned.
o All printed circuit boards have been cleaned of dust and grime.
o Amplifier boards have had 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 have
been replaced by modern uprated higher capacity versions.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.
The unit has been connected to a Quad 33 pre-amplifier and Quad 67 CD player and been soak-tested for eight hours continuously.
 |
10000uF 100V PSU capacitors and 10000uF 63V Speaker Coupling Capacitors |
|
WiMA bypass capacitors and Evox input Coupling Capacitors |
| 
|
original clamps using metal spacers | Panasonic FJ, Nichicon Muse and Elna Starget audio grade capacitors |
The Quad 303 produces 45W RMS into 8 ohm speakers. The unit will function either at 100-125 or 200-250V, 50-60Hz mains voltages. The Quad 303 is designed in combination with the Quad 33 pre-amplifier with which it excels. Frequency Response is very flat from 30 Hz to 20KHz. Total Harmonic Distortion less than 0.001%.
Dimensions are: 120mm wide, 159mm high and 324mm deep or 4.75" wide, 6.25" high, 12.75" deep. 
|  |
Panasonic FJ , Evox and Nichicnon
capacitors | All capacitors potted to
prevent movement |
The unit will be supplied with a mains lead with a UK plug at one end and an original Bulgin power plug at the other. The unit will be supplied with the full manual and circuit diagrams on CD.
Quad 303 Amplifier 
