QUAD 33 preamplifier

The QUAD 33 is one of the rare emblematic high-fidelity products. He left his mark on several generations of music lovers and audiophiles.

It still remains one of the most popular models in history and from Quad, one of the best-known Hi-Fi brands in the world. The first QUAD 33 left the manufacturer's factories in 1967 and during all these years it symbolized a benchmark in terms of high fidelity.

By revisiting the QUAD 33, the brand demonstrates its desire to reconnect with authenticity and history!

QUAD 33: Façade:

The QUAD 33 offers a design that totally evokes QUAD's past while being part of an obvious modernity.

The steel housing is very rigid and is perfectly assembled with quality. The anodized faceplate is precision machined. It incorporates all the codes of its illustrious ancestor, but with a much higher quality of component and manufacturing. This new version will not be prone to cracking or fading like the QUAD 33 from the 70s was.

The controls completely echo the original concept. Logically grouped for easy program selection and control, a backlit LCD displays states, adjustments and values. The same backlighting principle is applied to each of the push buttons, which makes the functions very readable. A row of three endless rotary encoders provides intuitive and immediate control of fine adjustments.

It is possible to adjust brightness and contrast, and perform a simple on/off setting to suit user preferences.

QUAD 33 : Connexions 

The QUAD 33 is equipped with fully balanced unbalanced (RCA) and balanced XLR analog input and output!

Power the speakers through the power amplifier using dedicated stereo pre-outputs, with RCA line level and a balanced XLR pre-out option. For added versatility and functionality, there is also an AUX output.

QUAD 33: Phono input

The all-new phono preamp is compatible with moving magnet (MM) and low-level moving coil (MC) cartridges. This stage has been particularly carefully designed and offers unprecedented performance for a device in this range. It uses only components with very low noise and very low distortion specifications. With a gain of 46 dB for the MM and 63.5 dB for Quad 33 is compatible with the majority of phono cartridges on the market.

QUAD 33 : Technology 

The Quad 33 preamplifier is QUAD's first solid-state design, following several famous tube designs.

The RND was entrusted to a "dream" team consisting of Rob Flain and Paul McConville (the most experienced QUAD service engineers in the world), Jan Ertner (30 years of experience in QUAD design), Peter Comeau (the acoustic director behind some of the QUAD loudspeakers), and David McNeill (the industrial designer responsible for two decades of QUAD innovations). They all participated in this work without compromising. These designers sought at each stage of the design of the new circuit to get as close as possible to the original sound and if possible improve it.

This QUAD 33 is equipped with digital microprocessor control, but it remains faithful to a completely analog design.

Master volume control is handled by a fully analog motorized ALPS potentiometer. This component, of excellent quality, is precise, offers a low noise level and a long lifespan.

The original QUAD 33 offered filters considered essential in 1967. Today these controls are no longer necessary, the new QUAD 33 offers bass control, tilt control and balance control to allow fine adjustment without unnecessarily encroaching on the harmonic range essential for realistic reproduction.

The bass control allows adjustment from -3 to 3 dB. It is ideal for subtle adjustments in the low frequencies, to add body to thinner source material. Or, conversely, to reduce low tones in the event of a room effect. 

Developed by QUAD founder, the legendary Peter Walker, the Tilt control is an audiophile-grade solution for tone adjustment. Its design stems from the belief that traditional tone and EQ controls are inadequate and clunky when it comes to adjusting tonal balance.

The Tilt control differs in that it adjusts the two ends of the frequency spectrum together, either by cutting the bass and boosting the treble, or by boosting the bass and cutting the treble in 1dB increments. It rotates or tilts the audible frequency range on a 700 Hz axis, thereby adjusting the overall sound balance with "warm" or "cold" notes without changing the volume or adding color to the sound. This feature is unique to this device. It provides a subtle, precise and consistent way to adjust system performance and compensate for recordings or the environment.

These Tilt, Bass and Balance controls are all composed of low-noise optoelectronic amplifiers, electronic switches and MELF low temperature coefficient metal film resistors, forming a negative feedback adjustment circuit.

QUAD 33: Test and listening

In launching this project, it was decided that the new Quad 33 and 303 combination would only see the light of day if performance was improved over the original creations. Every stage of development and every innovation was thoroughly tested and fully agreed with QUAD's technical design and service team.

The numerous circuit improvements and the addition of an impressive number of controllers place the new QUAD 33 technically well above its ancestor.

As chance would have it, we have in our hands a QUAD 33/303 pair from 1970.
We can confirm that the new Quad 33 has all the musicality and smoothness of the original models. But the 33 preamp marks a huge difference from the original version. Transparency and definition are far superior without distorting the timbre. Noise and distortion levels are very low, if not inaudible. This little preamp is remarkable for its fullness and presence in the midrange. The quality of its phono input is also noteworthy, and seems to be unheard of in this price range.
I've always felt that the Quad 33 wasn't up to the task of amplification, but now it is! This new version is far superior to the previous models

This Quad 33 coupled with the 303 (or not) offers remarkable value for money.


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