QUAD 33 preamplifier

Although as true to the original design as possible, the new set is equipped with modern conveniences. For example, the amplifier now has an XLR connection for optimum signal transfer. A completely renewed phono stage that supports both MM and MC cartridges.

The preamplifier can be operated with an infrared remote control.
This makes the set ideal for demanding users who want to enjoy the classic Quad experience in a contemporary design.

An overhaul of the QUAD 33 and 303 components, QUAD demonstrates its authenticity, pedigree and excellence as a powerhouse in the British hi-fi world – both past and present.

Redevelopment

When listing the names involved in the development of this beautiful iteration of an icon, you will find a calculation of almost 200 years of engineering experience and over 100 years of QUAD-exclusive design and service.

A dream team of Rob Flain & Paul McConville (the most experienced QUAD service engineers in the world), Jan Ertner (30 years of QUAD design experience), 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).

They were all part of this loving effort, where no compromise was made in the demand for a product that could bear the name of 33 and 303.

The exterior design is specifically designed to continue QUAD's tradition of practical simplicity. However, it would be foolish to overlook the implementation of modern features, such as an informative backlit display, subtle LED lighting, and remote control functionality.

And just like the original, the overall look is unmistakably QUAD! Albeit now with a high-quality machined and anodized front panel and an all-metal chassis.

Features QUAD 33 preamplifier

The new QUAD 33 is supported by digital microprocessors, but otherwise remains faithful to a classic analog design.

The 33 powers the speakers via the power amplifier using dedicated stereo preamp outputs. Featuring an RCA line level and balanced XLR preamp output option. For added versatility and functionality there is also an AUX output.

Now equipped with fully balanced XLR inputs and outputs, the 33 stands apart from other preamplifiers and even its ancestor model.

The brand new phono preamplifier is Moving Magnet and Moving Coil compatible! With the ability to easily switch between the two options – no modifications or board upgrades required. With a gain of 46dB for the MM and 63.5dB for the MC, the input stage uses ultra-quiet audio operation.

This ultra-quiet performance is combined with high slew rates and very low distortion specifications. The RIAA processing circuit has its own dual Bipolar/JFET audio operational amplifier.

The JFET section of the input stage allows high slew rates to keep distortion low! Even when large output excursions are required.

Controls QUAD 33

The controls are comprehensive but simple. This again reflects the original design concept. Logically grouped to facilitate program selection and operation, a backlit LCD display communicates settings, adjustments and values.

The same backlighting principle is applied to each of the push buttons, further enhancing the intuitive design with a visual indication of input selection and mode. Illumination settings for buttons and the LCD display allow for brightness adjustment, contrast adjustment and a simple on/off setting to suit the user's preference.

Volume control

The main volume control is a fully analog, precision motorized ALPS potentiometer that provides long lasting, low noise performance. Not only is the volume control tactile and accurate, the motorized control will automatically rotate when adjustments are made via the remote.

An additional bank of three endless rotary controls provides intuitive and immediate control over the QUAD-specific fine-tuning settings.

The original QUAD 33, as well as many previous and subsequent QUAD preamplifier components, featured filters that were considered essential for "modern, good quality loudspeakers" (as was stated at the time).

Such controls are no longer needed. Therefore, by applying modern logic and suitability to today's technology, the new QUAD 33 presents bass adjustment, tilt control and balance control! To allow fine adjustment without unnecessarily interfering with the harmonic range essential for realistic reproduction.

Bass control

The bass control allows adjustment from -3dB to +3dB. Perfect for subtle adjustments to the low end, as a solution to add body to thinner source material. Or conversely, reducing bass tones in the case of 'boomy' sounds in the room.

Compared to the time of the launch of the original QUAD 33, speakers and source material have evolved mainly for the better. This evolution saw the adoption of the 'Tilt' control in the QUAD 33's successor, the QUAD 34 (1982).

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

Tilt control

The Tilt control differs in that it adjusts both ends of the frequency spectrum together, either cutting bass and boosting treble, or boosting bass and cutting treble in 1 dB increments.

Essentially, it rotates—or tilts—the audible frequency range on a 700Hz axis, adjusting the overall sound balance with warm or cool accents. This feature, unique to QUAD, offers a subtle, precise, and consistent way to adjust your system's performance. And to adapt to different recordings or environments.

The Tilt, Bass, and Balance controls are all comprised of low-noise op-amps, electronic switches, and low-temperature MELF metal film resistors. Together, these form a negative feedback adjustment circuit.