QUAD 33 & 303: BEST OF BOTH WORLDS?
Can you have the perfect balance of both worlds: the increased performance of a contemporary design with the unmistakable character of a classic? Quad seem to think you can. Their redesigned 33 and 303 pre and power amplifiers don’t just pay homage to their iconic 1960s predecessors—they elevate them. With their sleek aluminium finishes, advanced components like MM/MC phono stages, and customisable tone controls, they blend retro charm with cutting-edge performance. From the compact chassis to the powerful 200VA toroidal transformer, the 33 and 303 offer more than just sound—they offer balance, precision, and heritage, all in one compact package. Just how good a package, you ask? Well, let’s find out.
Quad 33 Preamplifier & Quad 303 Power Amplifier
QUAD 33 & 303 SPECIFICATIONS
33 and 303 are a heritage redesign of the instantly recognisable and iconic late sixties separate pre/power amplifiers from Quad, of the same name. The preamp inputs include a high-performance, low-noise MM and MC phono stage, a dedicated headphone amplifier, 3 x RCA and 1 x XLR inputs, and 1 x XLR out. A very welcome and “balanced” improvement on the original. Tone control features include Quad’s iconic ’Tilt’ adjustment, as well as bass and balance adjustments that can all be dialled in via remote or the physical tone controls on the face of the unit. It’s high-grade aluminium chassis is finished in Quad’s classic grey, with a few modern accents to help put a contemporary spin on things, and complimented by an orange backlit LED display and input selectors, honouring the more distinct features of the original.
Quad 303 is a 50W Class AB power amplifier ( a 5W jump over the original) sporting a custom 200VA toroidal transformer, Quad’s iconic 303 triples output stage, 10 ampere into difficult loads, so tons off current for thirsty speakers and demanding musical passages, and native bridge mode selection for dual mono setups. That’s right. You can bridge a pair of Quad 303 power amps, using them as monos, to more than double the wattage, giving you a bridged 140W into 8ohm or 170 into 4ohms. Front and back CNC-routed heated sinks book end an anodised silver chassis that is the epitome of mid century industrial design. Combined with exposed fastenings, embossed Quad logo, and its orange backlit power switch, Quad 303s stunning aesthetics prove that power really is seductive.
Both units, the 33 & 303, are rather small by conventional pre-power standards. Quad 33 dimensions comes in at a rather modest 258 x 165 x 83mm, while the power stage, Quad 303, comes in at just 325 X 176 X 120mm. The originals were designed as a sort of mini stack, at least by conventional build sizes at the time, and their modern remakes are apparently the exact dimensions of the originals. A testament to the old trope that big things really do come in small packages.
Quad 33 Preamplifier & Quad 303 Power Amplifier
MY GOD! THEY LOOK GOOD
What you need to know from the outset is just how breathtaking this combination is to look at. There’s nothing like this on the market. These aren’t pieces that you’ll want to stow away out of sight but sit front and centre for all to see – even the power stage. I love that there’s no timber to be found here. Are we getting to the end of our retro fetish for walnut, I wonder? Maybe. If you’re familiar with Audiolab – also from the IAG group – its high-grade aluminium finish is instantly recognisable. This is a combination of traditional six and seven thousand matt silver finishes with a hint of nine thousand series sparkle on the fascia of the Quad pre. It’s a gorgeous touch and one worthy of the asking price. The volume and tone controls are a slightly darker accent. It’s incredibly subtle. And their tones actually shift in the light, which is really luxe. And when combined with the orange accents from: the input selections, power buttons and backlit LED display – the first word that comes to mind is balance. New, old, the essence of the iconic original and no doubt a desire to fashion a worthy contemporary : quad have managed to balance those competing aspects to perfection, which is no mean feat. Yes, it’s clearly retro. But there’s something equally contemporary about this combination, too. It dances the line between new and old brilliantly. And so all I can think to say about its aesthetic is how perfectly balanced it all is, and that, as a result, you’re left with not some cheap play on nostalgia but a highly refined pre-power system that’ll be the talking point of any conversation in your listening space. I used to think loudspeakers were the sole wow factor in a pretty setup. 33 & 303 have completely changed my view on that.
TOPOLOGY: BETTER CIRCUIT DESIGN
Vastly superior internal components. Greater chassis realestate to improve circuitry architecture (topology). And complete isolation from power supply/high-power circuitry noises. These are the reasons for separating pre and power amplification. Because what it translates to is demonstrably better clarity, detail, soundstage, imaging and dynamics.
Top shelf circuitry architecture, otherwise known as topology, is a little like Michelin-style dining, right. Not only are you getting the highest quality ingredients – in this case a custom-specified toroidal transformer; reservoir/smoothing capacitors; and ultra-low-noise regulators – but each work station within the kitchen itself is arranged in manner so as not to interact with or negatively affect the surrounding work stations. So, again, with regards to the Quad 33, there are five independent work stations – 1 x XLR, 1 x Phono, 3 x RCA – with five regulated supply rails, including ultra-low-noise regulators with extensive measures employed to prevent contamination and cross-coupling (materials from one work station messing with the flawless functioning of another) and each arranged for the shortest, most direct path to service area. Why? Because superior linearity – a fancy way of saying short, direct signal paths – ensure your audio doesn’t get lost or distorted on its way to your speakers.
And when you isolate this entire process from the main power supply and its high-power circuitry, because, let’s face it, it doesn’t take a genius to figure out what happens to the meals when you drop a coal fire power plant inside a Michelin kitchen – any kitchen for that matter, really – the precision, the delicacy, the “Je ne sai quoi’ taking place here is completely free from contamination. This level of circuitry design is the finest of fine dining and it’s all done to ensure that the finished dish, your favourite piece of music, in whatever format you decide – streaming, records, whatever – is nothing short of sublime.
TILT BALANCE & BASS CONTROL
Let’s talk controls. Quad 33 has two levers of tonal adjustment available to you: bass and tilt control. Bass alone can be adjusted from -6dB to +6dB. So you can add weight to thinner source material or just as easily reduce that weight if speaker positioning or certain room acoustics are producing boom.
To accompany this is Quad’s iconic ’Tilt’ control feature. Created by Quad founder Peter Walker in the late 60s as a more musically accurate approach to tonal adjustment, Tilt control essentially tilts the entire frequency spectrum, on a 700Hz axis, in steps of 1dB. Meaning that if you lift bass you also by default lower treble, and vice versa, giving you either ‘warm’ or ‘cool’ tonal outcomes that neither affect volume nor introduce colour. Ranging from - to + 3dB, Tilt control allows you to compensate – with greater consistency, subtlety and precision – for things like recordings, speaker pairings, and room acoustics. Again, all without negatively impacting the overall sound performance.
In addition to bass and Tilt control is balance, another faithful carry-over from the classic QUAD 33. And it’s quite simply a left/right channel output adjustment to suit listener preferences or the environment. Now, all of these control adjustments are available to you via remote or the physical selectors on the Quad 33 unit itself, and indicators for each adjustment are visible on the unit’s LCD display allowing you to very easily see exactly what you’ve adjusted and by how much, which is very helpful indeed.
PHONO: TURNTABLE HEAVEN
33 & 303 are distinct heritage pieces. They ooze nostalgia. A certain romance so many of us share for the late 60s early 70s, a key period in music’s history that’s riddled with folklore, mysticism and legend. There’s little doubt that the hearts of new 33 and 303 owners are steeped in the legends of that era, which is also the golden era of vinyl records. So having a high quality internal phono preamplifier was a must for the designers working on this unit. And what a phono pre it is.
First and foremost is the inclusion of Moving Coil functionality. This is a serious pre / power system for serious listeners, right. Listeners that will almost undoubtedly be vinyl listeners, and pretty serious vinyl listeners at that. So, the introduction of Moving Coil here, which is arguably a more audiophile-grade style of cartridge, is a real boon. And you can switch between MM and MC functionality via a cycle press of the phono button, either on the remote or the unit itself.
Now, the RIAA phono stage used in the 33 is a Dual Bipolar/JFET Audio Operational Amplifier. The bipolar transistors are best known for being very precise and quiet, while the JFET transistors are known for being very fast and smooth-sounding as well as drawing much less current. The new 33’s total harmonic distortion, in addition to noise, equals that of previous versions but at much lower supply currents. Meaning you get improved sound performance in a more efficient, reliable design. This ultra-low-noise design is combined with very low distortion specifications and high slew rates, which are responsible for more lively, detailed and dynamic vinyl performances.
Basically, this phono stage was designed with the modern listener in mind, while still paying homage to the all-analogue appeal of the original 33. The inclusion of a switchable MM/MC function addresses a long-requested feature from dedicated users of the original 33 and ensures that the new 33 continues to be a beloved piece of hi-fi equipment, perfectly suited to today’s vinyl resurgence and the serious vinyl junkies that support it.
Quad 33 Preamplifier & Quad 303 Power Amplifier (in bridge mode)
MORE POWER
At the heart of Quad 303 is 50W of continuous power per channel into 8Ω loads, 70W into 4Ω. And while 50W of Class A/B power might seem modest by contemporary standards, too much attention is sometimes paid these days to published power outputs without considering other factors. Because, in reality, the new 303 can drive a wide range of demanding speakers with as much ease as a typical 100W rating. However, many of those 100W amps, at least according to Quad, would likely lack the 303’s finesse.
And that’s certainly been my experience. As far as I’m concerned this combo pumps. But boy does it sparkle. I’ve used it with three different speaker models. Quad’s Revela bookshelf loudspeakers you see in the setup behind me. Castle’s UK-Made and Karl Heinz-Fink designed Windsor Earle (my personal fav). And even the Super Lintons, which the 303 tore into with zero effort. But, again, it’s the finesse they deliver that’s so dang impressive. And that’s no doubt due, in large part to both its 200VA toroidal transformer and Quad’s famous ‘Symmetrical Triples’ output stage.
Now, its 200VA toroidal transformer has been custom built for the 303 specifically and is capable of delivering a maximum current of 10A into difficult loads. This allows the 303 to maintain tight control over your speakers, even with dynamic changes in the music.
Peter Walker’s ‘Triples’ output stage effectively forms a feedback amplifier-within-an-amplifier, providing a fully symmetrical output that significantly minimises distortion across the audio spectrum. With exceptional thermal stability and reduced total harmonic distortion to less that 0.003% at 1kHz, the ‘Triples’ design gives you a remarkably accurate amp that’s virtually immune to temperature fluctuations. So you get pure and transparent sound, preserving the details and dynamics of the original recording, even at high volume, under demanding loads, and over long periods of use. Its finesse is truly a work of art.
So, while the designers could’ve jammed more Watts down the throat of this classic remake to be inline with more contemporary trends, they couldn’t have done so without changing the circuit and characteristics to such a degree that it no longer represents a true 303. And, at least in my experience, it certainly doesn’t need to. But with the clever little addition of bridge mode, you can increase your Wattage without upsetting the fitness of 303’s beguiling character. A pair of 303 power amps can be bridged in a dual mono setup to deliver 140W per channel into 8Ω. And if its performance at 50W is anything to go by, 140 would be out of this world.
THE WRAP UP
The Quad 33 and 303 walk the fine line between modern innovation and timeless heritage, staying true to the soul of the originals while introducing meaningful upgrades. Their design, which honours those gorgeous mid-century aesthetics, and advanced internal components, make them as relevant today as they were decades ago. This perfect balance of old and new delivers not just raw power, but a nuanced listening experience that pays homage to its legacy. As a piece of heritage audio, the 33 and 303 offer an authentic, yet refreshed take, for audiophiles who want the best of both worlds—modern performance paired with the unmistakable character of a true classic.