Quad 303 is a two channel power amplifier primarily designed for high quality domestic installations. It is ideally suitable for driving loudspeakers in the 4-16 ohm range and will provide an output of up to 45 watts per channel depending upon the load impedance. The input required for full output is 0.5 Vrms unbalanced. Transistor triples are employed in an original circuit to provide a completely symmetrical output stage, quiescent current independent of junction temperature and symmetrical current and voltage limiting. Harmonic and intermodulation distortion products in the audio range are so low that they are difficult to measure in meaningful terms. The amplifier is unconditionally stable and may be used with any load. For special applications requiring continuous power into low (less than 8 ohm) or reactive loads such as driving synchronous motors, etc, the maximum power or duty cycle may be limited by the ability of the heat sink to dissipate the heat generated (max heat sink temperature 70 degrees). The two channels may be used together or independently but the two outputs should not be paralleled without incorporating some form of current sharing network. Specifications Power output: 45 watts per channel into 8Ω (stereo) Frequency response: 30Hz to 35kHz Total harmonic distortion: 0.1% Input sensitivity: 0.5V Signal to noise ratio: 100dB Speaker load impedance: 4Ω to 16Ω Dimensions: 120 x 159 x 324mm Weight: 8.2kg She is in fantastic condition and plays perfectly there is a mark on the top cover and 1 fin is a little bent these do NOT AFFECT her sound at all and are part of the sale. As is. Please see detailed photographs of the condition. She play tests spectacularly good and im happy to re home her. Please note that vintage electronic items are not guaranteed. We will ship her with our custom double box and bubble wrap system and we pack for the safety of the item not for economy