A dream team of Rob Flain & 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 Quad 33 Preamplifier and Quad 303 Power Amplifier.

The external design is specifically intended to continue the QUAD tradition of practical simplicity. Yet, it would be foolish to ignore the implementation of modern-day capabilities, such as an informative backlit display, delicate LED illumination and remote control functionality; and just like the original, the overall appearance is unmistakably QUAD, albeit now with a premium machined and anodised front panel and all-metal chassis.

The new QUAD 33 is supported by digital microprocessor control but is otherwise faithful to a classic analogue design.The 33 feeds the loudspeakers via the power amplifier using dedicated stereo pre-outputs, with an RCA line-level and balanced XLR pre-out option. For additional versatility and functionality, there’s also an AUX output. Now equipped with fully balanced XLR inputs and outputs, the 33 is set apart from other preamplifiers and even its forefather model.

The brand new phono stage is Moving Magnet and Moving Coil compatible with the ability to simply switch between the two options – no mods or board upgrades necessary. With a gain of 46dB for the MM and 63.5dB for the MC, the input stage uses ultra-low noise audio op-amps.

This ultra-low noise 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 portion of the input stage enables high slew rates to keep distortion low, even when large output swings are required.

The controls are comprehensive but simple. Again, this echoes the original design concept. Logically grouped to facilitate selection and control of the programme, a backlit LCD screen relays 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 screen allow for brightness adjustment, contrast adjustment, and a simple on/off setting to suit the user’s preference.

The master volume control is a fully analogue, precision motorised ALPS potentiometer offering long-life and low-noise performance. The volume control is not only tactile and precise; its motorised operation will automatically rotate when adjustments are made via the remote control.

A further row of three endless rotary encoders offer intuitive and immediate control over the QUAD-specific fine-tuning settings. The Tilt control, Bass control, and Balance controls are all composed of low-noise op-amps, electronic switches, and MELF low-temperature coefficient metal film resistors, forming a negative feedback adjustment circuit.

Technical Specifications

Model: QUAD 33
General Description: Pre Amplifier
Inputs: 3 x RCA, 1 x Balanced XLR (pair), 1 x Phono (MM / MC switchable)
Outputs: 1 x RCA (AUX), 1 x XLR, 1 x RCA (Pre Out), 1 x Headphone, 2 x 12 V Trigger Out
Pre Amplifier Section
Gain:
0 dB (Line / XLR)
+46 dB (Phono MM)
+63.5 dB (Phono MC)
Input Sensitivity:
695 mV (Line / XLR)
3.2 mV (Phono MM)
460 uV (Phono MC)
Input Impedance:
10 k (Line / XLR)
47 k/100 pF (Phono MM)
100 R/1.7 nF (Phono MC)
Total Harmonic Distortion (THD):
<0.0005 % (1 kHz, Line / XLR)
<0.002 % (1 kHz, Phono MM / MC)
Frequency Response: 20 Hz – 20 kHz (+/-0.2 dB)
Signal-to-Noise ratio (S/N):
&gt:108 dB (A-weighted, Line / XLR)
&gt:82 dB (A-weighted, Phono MM)
&gt:74 dB (A-weighted, Phono MC)
Output Impedance: 120 ohms
Headphone Amplifier
Total Harmonic Distortion (THD): < 0.01 % (1 kHz, 50 mW)
Output Impedance: 2.35 ohms
Load Impedance: 20 – 600 ohms
Standby Power Consumption: <0.5 W
Net Weight: 4.0 kg
Dimensions (W x H x D): 258 x 82.9 x 165 mm
Finish: Classic QUAD Grey
Power Requirements: 220 – 240 V – 50 / 60 Hz, 100 – 120 V – 50 / 60 Hz