QUAD 303

QUAD 303 Amplifier – Power and Precision in an Iconic Design

The QUAD 303 is a modern reinterpretation of the iconic Class AB stereo power amplifier, launched in 1967. This model retains the characteristic QUAD industrial design, reproducing the aesthetics of its predecessor, but enriched with an orange LED backlit standby button. Compact and powerful, the QUAD 303 is the ideal partner for the QUAD 33 preamplifier, offering a very high level of audio performance with the ability to drive even difficult loads, making it perfect for the needs of modern enthusiasts.

Technical Features

High Power Output: Delivers 50W per channel into 8 Ohm and 70W into 4 Ohm, with a maximum current output of 10 Amps, ensuring stability even on demanding speakers.

Mono Mode Configuration: Supports a mono bridge configuration, reaching a power of 140W on 8 Ohm and 170W on 4 Ohm, ideal for high-power audio systems.

Proprietary Symmetrical Triples Circuit: The QUAD 303 integrates the exclusive Symmetrical Triples circuit, which maintains perfect symmetry in the output stage and minimizes distortion. This innovative system ensures that the transistors work within the optimal parameters, improving reliability and sonic performance even in dynamic conditions.

Performance and Thermal Stability

Advanced Linearity and Thermal Stability: The advanced output stage offers excellent linearity and exceptional thermal stability, preserving the timbre quality and dynamics of the sound.

Custom Toroidal Transformer: The amplifier is powered by a custom made 200 VA toroidal transformer with ultra-low noise, which ensures constant and clean power.

Overload Protection: The protection circuit prevents damage from overload and short circuit, making the QUAD 303 durable and reliable even in heavy use.

Connectivity and Design

Audiophile-Quality Inputs and Outputs: The QUAD 303 features balanced XLR and unbalanced RCA inputs, and two 12V trigger ports (In/Link) for easy integration with other devices.

Anti-Vibration Design with Aluminum Heatsinks: The rigid, anti-vibration chassis features double-sided anodized aluminum heatsinks, CNC machined for optimal heat dispersion.

Classic Aesthetics with QUAD Grey Finish: The Classic QUAD Grey finish echoes the iconic style of the original, combining vintage charm with a solid, contemporary structure.

Performance Specifications

Linear Frequency Response: With a frequency response of 20 Hz to 20 kHz (+/- 0.2 dB) and a total harmonic distortion (THD) of less than 0.002%, the QUAD 303 delivers detailed and balanced sound.

Optimal Signal to Noise Ratio: Greater than 108 dB (S/N Ratio, A-weighted), ensures a clear listening experience without unwanted background noise.

Dimensions and Weight

Compact and Robust: With dimensions of 120 x 176 x 325 mm and a weight of 8.4 kg, the QUAD 303 is easy to position without compromising on build quality.

The QUAD 303 is a power amplifier that combines tradition and innovation, offering exceptional performance for faithful and passionate sound.

Solid-state stereo power amplifier in Class AB, faithful and technologically updated reinterpretation of the unmistakable and legendary QUAD 303 marketed in 1967, ideal partner for the QUAD 33 preamplifier - compact chassis with an attractive Industrial Design aesthetic, adhering to the look of the original model, embellished with a modern Standby button backlit with orange LED light - excellent driving qualities and ability to handle very complicated loads - power 50 Watts per channel into 8 Ohm and 70 Watts per channel into 4 Ohm with output current up to 10 Amperes - mono bridge configuration option with power of 140 Watts into 8 Ohm and 170 Watts into 4 Ohm - implementation of the renowned proprietary QUAD Symmetrical Triples circuit, with a perfectly symmetrical output stage, whose constant and effective control of the output current and voltage allows the transistors to operate in a completely protected manner and always within their limits recommended parameters, ensuring absolute performance and reliability in any condition, with distortion levels hundreds of times lower than those intrinsically present starting from the source signal - advanced output stage characterized by extreme linearity and exceptional thermal stability, with remarkable performance in terms of dynamics, control and richness of tone - linear power supply stage with Custom Made very low noise 200 VA toroidal transformer - protection circuit against overloads and short circuits - extremely rigid anti-vibration chassis, shaped front with massive lateral heat sinks in anodized aluminum machined from solid with CNC numerical control machines - stereo inputs: 1x L/R balanced XLR, 1x L/R unbalanced RCA - 2x 12 V trigger ports (In / Link) - frequency response 20 Hz - 20 kHz (+/- 0.2 dB) - total harmonic distortion (THD, 1 kHz) less than 0.002% - signal/noise ratio (S/N Ratio, A-weighted) higher than 108 dB - Classic QUAD Grey finish - dimensions (W x H x D) 120 x 176 x 325 mm - weight 8.4 Kg