{"product_id":"quad-303-power-amplifier-open-box","title":"Quad 303 Power Amplifier (Open Box)","description":"\u003cdiv\u003e\u003cspan\u003eVery few Hi-Fi components are as instantly recognisable as the QUAD 33 and 303, and for that we make no apologies!\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003eStill one of the most popular models in the history of one of the world’s most poignant Hi-Fi brands, the QUAD 33 and 303 are benchmarks in almost every angle of desirable audio equipment – performance, reliability, industrial design, value and musical romance.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eBy revisiting the QUAD 33 and 303 components, QUAD demonstrates its authenticity, pedigree and excellence as a juggernaut of the British hi-fi world - past and present.\u003cbr\u003e\u003cbr\u003eIn listing the names involved in the development of this stunning iteration of an icon, you’ll find a calculation of close to 200 years of engineering experience and 100+ years of QUAD-exclusive design and service.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eA dream team of Rob Flain \u0026amp; Paul McConville (the world’s most experienced QUAD service engineers), Jan Ertner (30 years of experience in QUAD design), Peter Comeau (the acoustic director behind some of QUAD’s most successful loudspeakers) and David McNeill (the industrial designer responsible for two decades of QUAD innovations) were all a part of this labour of love, making no compromise in the demand for a product that could bear the name of 33 and 303.\u003cbr\u003e\u003cbr\u003eThe QUAD 303 power amplifier was intended for normal domestic use with loudspeakers of moderate efficiency, but was also used by broadcasting and recording studios, worldwide, who appreciate its excellent performance and dependability. The ethos hasn’t deviated.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\n\u003ch2\u003eFunction\u003c\/h2\u003e\n\u003cp\u003eThe outstanding performance of the QUAD 303 is still celebrated to this day, and is largely due to the unique output circuit developed by QUAD.\u003cbr\u003e\u003cbr\u003eIn reissuing the QUAD 303 power amplifier concept, exactly like the matching 33 preamplifer, QUAD’s incomparably experienced service team was matched with the equally adept engineering team to reinvoke the design, romance and performance in a thoroughly modern iteration of a hi-fi legend.\u003cbr\u003e\u003cbr\u003eAs with the new QUAD 33, every aspect of design and performance has been analysed and re-engineered way beyond simply modernising components and refreshing of specifications.\u003c\/p\u003e\n\u003cp\u003eThe QUAD 303 power amplifier was intended for normal domestic use with moderately efficient loudspeakers, but it was also used by broadcasting and recording studios worldwide, who appreciated its excellent performance and dependability.\u003c\/p\u003e\n\u003cp\u003eThe ethos hasn’t deviated. The original 33 and its partnering 303 were awarded with a ‘Council ofIndustrial Design Award in 1969’. Even today, the original design is celebrated and confirmed by its presence at the Museum of Modern Art in New York. The new 33 and 303 have been industrially engineered to surpass those original standards, with a truly modern appearance and functionality.\u003c\/p\u003e\n\u003ch2\u003eCircuitry\u003c\/h2\u003e\n\u003cp\u003eHowever, much like the original, the new QUAD 303 maintains its faithfulness to the original by employing the famous QUAD ‘symmetrical triples’. Employed to provide a completely symmetrical output stage, greatly reducing distortion and rendering the resting current independent of output transistor temperature.\u003cbr\u003e\u003cbr\u003eThis development enables the designers to reduce distortion to emphatically low levels without sacrificing stability and to maintain this excellence under all dynamic conditions.\u003cbr\u003e\u003cbr\u003eTo put this in perspective, the lowest theoretical distortion present on the very source material will still be some hundred times greater than that the QUAD 303!\u003c\/p\u003e\n\u003cp\u003eSuch a level is, of course, completely inaudible no matter how refined the test.\u003c\/p\u003e\n\u003cp\u003eThe use of ‘triples’ permits simple and effective control of the output current and since the voltage is also controlled, the output transistors are completely protected and must always operate within their ratings with the obvious advantages of greatly improved reliability under all conditions, without the use of elaborate and expensive circuitry.\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cspan\u003eDue to the lack of complementary transistors (NPN and PNP power transistors) in earlier times, the older QUAD 303 used a quasi-complementary output stage. The new version of the QUAD 303 now uses a fully complementary output stage, providing better linearity, more stable static bias, and improved stability under high voltage and large current conditions. Using premium power transistors, the 303 offers excellent gain linearity for accurate reproduction of the input signal with greater dynamic range.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eThe amplifier cannot be upset even when overdriven by an asymmetrical signal or by shorting or disconnecting the loudspeakers.\u003cbr\u003e\u003cbr\u003eA brand new 200VA, custom-specified, low-noise toroidal transformer has been developed for the new 303.\u003cbr\u003e\u003cbr\u003eThe output stage of the discrete power amplifier circuit employs an advanced feedback topology to ensure superior linearity and exceptional thermal stability. Through its Class AB design, the ideal current is maintained independently of the temperature of the output transistors.\u003cbr\u003e\u003cbr\u003eThe result is a compact, cool-running power amplifier that possesses the capacity to deliver dynamic power and maintain a firm hold on the music while providing rich sonic detail.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eAlways respected for its conservative but consistent power-output, the classic QUAD 303 was officially rated at 45W @ 8 ohms. A modest but honest output, the 303’s venerability is in the finesse of the performance, not just the raw power. The new model is thoroughly the same.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eHowever, with some tweaking and enhancements, the 303 is loaded with a little extra power – offering 50W @ 8 ohms (70W @ 4 ohms) with a maximum current delivery of 10A into difficult loads. The original 303 was known to have issues with lower impedance loads, the new 303 has no such trouble. Perfectly suited to the more demanding requirements of the modern audiophile, it ensures any speakers – even including QUAD’s electrostatic designs – can be driven with ease. Connectivity options comprise single-ended RCA and balanced XLR inputs, a 12V trigger input and high-quality speaker binding posts. Simple, solid and thoroughly authentic, inside and out. The power output for 'bridged mode' (for use as a mono-block power amplifier) reaches 140W @ 8 ohms or 170W @ 4 ohms (bridged mono).\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cspan\u003eSpecs\u003c\/span\u003e\u003c\/h3\u003e\n\u003ctable class=\"product-specifications-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003eQUAD 303\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGeneral Description\u003c\/td\u003e\n\u003ctd\u003ePower Amplifier\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDesign Philosophy and Core Technology\u003c\/td\u003e\n\u003ctd\u003eClass AB Power Amplifier\u003cbr\u003eQUAD 303 Triples Output Stage\u003cbr\u003eCustom 200VA Toroidal Transformer\u003cbr\u003eStereo\/Bridge mode selection\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInputs\u003c\/td\u003e\n\u003ctd\u003e1 x Line, 1 x XLR\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOutputs\u003c\/td\u003e\n\u003ctd\u003e1 x 12V Trigger\u003cbr\u003e1 x Stereo Speaker, 1 x 12V Trigger (Link)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Amplifier Section\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGain\u003c\/td\u003e\n\u003ctd\u003e+29dB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRated Power Output\u003c\/td\u003e\n\u003ctd\u003eStereo: 2 x 50W (8 ohms, THD\u0026lt;1%)\u003cbr\u003eStereo: 2 x 70W (4 ohms, THD\u0026lt;1%)\u003cbr\u003eBridged: 140W (8 ohms, THD\u0026lt;1%)\u003cbr\u003eBridged: 170W (4 ohms, THD\u0026lt;1%)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFrequency Response\u003c\/td\u003e\n\u003ctd\u003e20Hz - 20kHz (+\/-0.3dB)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTotal Harmonic Distortion (THD)\u003c\/td\u003e\n\u003ctd\u003e\u0026lt;0.002% (1kHz)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Impedance\u003c\/td\u003e\n\u003ctd\u003e10k ohms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput Sensitivity\u003c\/td\u003e\n\u003ctd\u003e700mVrms (Line)\u003cbr\u003e1.5Vrms (XLR)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSignal-to-Noise Ratio (S\/N)\u003c\/td\u003e\n\u003ctd\u003e\u0026gt; 108dB (A - weighted)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax. Output Current\u003c\/td\u003e\n\u003ctd\u003e10A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGeneral\u003c\/td\u003e\n\u003ctd\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStandby Power Consumption\u003c\/td\u003e\n\u003ctd\u003e\u0026lt;0.5W\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNet Weight\u003c\/td\u003e\n\u003ctd\u003e8.4kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGross Weight\u003c\/td\u003e\n\u003ctd\u003e9.5kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions (mm) (W x H x D)\u003c\/td\u003e\n\u003ctd\u003e120 x 176 x 325\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCarton Size (mm) (W x H x D)\u003c\/td\u003e\n\u003ctd\u003e226 x 312 x 462\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFinish\u003c\/td\u003e\n\u003ctd\u003eClassic QUAD Grey\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Requirements (depending on region)\u003c\/td\u003e\n\u003ctd\u003e220 - 240V - 50 \/ 60Hz\u003cbr\u003e100 - 120V - 50 \/ 60Hz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStandard accessories\u003c\/td\u003e\n\u003ctd\u003ePower Cord, Remote Control, User Manual\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e","brand":"Quad","offers":[{"title":"Default Title","offer_id":57364108050805,"sku":"KRO3456756432","price":1179.95,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/2222\/0805\/files\/303_Silver_Standard_1.webp?v=1731338660","url":"https:\/\/www.kronosav.com\/en-ie\/products\/quad-303-power-amplifier-open-box","provider":"Kronos AV","version":"1.0","type":"link"}