The legendary Quad 33 returns in a stunning 2024 edition. This iconic British preamplifier combines classic design with modern refinements including MM/MC phono stage, balanced XLR connectivity, signature Quad tilt control, dedicated current-feedback headphone amplifier, and motorised volume control - all in the compact chassis that defined high-fidelity for generations.
The Quad 33 preamplifier needs little introduction. Between 1967 and 1982, over 120,000 units were sold, making it one of the most successful and beloved preamplifiers in hi-fi history. Now, after decades of requests from audiophiles worldwide, Quad has reimagined this icon for the 21st century while staying faithful to the design philosophy that made the original a legend.
Iconic Design, Modern Execution:
Very few hi-fi components are as instantly recognizable as the Quad 33. The 2024 edition honors Peter Walker's original industrial design while incorporating thoughtful modern refinements. The compact 258mm-wide chassis retains its classic proportions, now executed in substantial slabs of anodized aluminum with a matte silver finish - far more robust than the folded metalwork of the original.
The signature control layout remains: volume control on the left, three flush-mounted rotary encoders on the right. But look closer and you'll spot the updates. The original's orange strip labeling is now a backlit LCD screen with adjustable orange backlighting. All buttons beneath the rotary controls are now illuminated with LEDs, providing visual feedback of input selection and mode. Between the two rows of orange buttons sit a 6.35mm headphone socket and IR remote sensor - features the original never dreamed of.
Legendary Tilt Control:
At the heart of the Quad 33 philosophy is the famous tilt control - a feature so elegant and musically effective that it's been copied by countless manufacturers over the decades. Instead of conventional bass and treble controls with all their limitations, the tilt adjustment seamlessly pivots the frequency response around a carefully chosen 700Hz axis in 1dB steps up to +/-3dB.
Want to add air and brilliance to vintage recordings? Rotate clockwise to gently lift the treble while reducing bass for improved clarity and presence. Need to tame an overly bright modern recording or add weight and warmth? Rotate counter-clockwise to lift the bass and roll off the highs, adding depth and perspective. The effect is subtle, musical, and far more natural than conventional tone controls. With the included remote control, you can make these adjustments from your listening position where the perceptual effect actually matters.
State-of-the-Art Phono Stage:
The new Quad 33 features a completely redesigned phono stage that's switchable between Moving Magnet and Moving Coil operation with no modifications or board upgrades required - simply flip a switch. The MM stage provides 46dB of gain while the MC stage delivers 63.5dB, making it compatible with even low-output cartridges.
The phono circuit employs ultra-low-noise audio operational amplifiers with high slew rates and vanishingly low distortion specifications. The RIAA equalization processing uses a dual Bipolar/JFET operational amplifier topology. The JFET input stage enables high slew rates to keep distortion low even when large output swings are required during loud passages or transient peaks.
Input impedances are optimized at 47kΩ/100pF for MM cartridges and 100Ω/1.7nF for MC types. With signal-to-noise ratios exceeding 82dB for MM and 74dB for MC (both A-weighted), even the quietest vinyl passages emerge from a vanishingly black background.
Comprehensive Connectivity:
The 2024 Quad 33 goes well beyond its predecessor's capabilities. Where the original featured DIN sockets, the new version offers:
Inputs:
- 3 pairs of single-ended RCA line-level inputs
- 1 pair of balanced XLR inputs
- 1 pair of RCA phono inputs (MM/MC switchable)
Outputs:
- 1 pair of single-ended RCA pre-outputs
- 1 pair of balanced XLR pre-outputs
- 1 pair of RCA AUX outputs for recording or additional amplification
- 1 x 6.35mm (1/4") headphone output
- 2 x 12V trigger outputs for system integration
The inclusion of both balanced XLR and single-ended connectivity sets the new 33 apart from other preamplifiers in its class and even its legendary predecessor. This allows optimal interfacing with modern balanced source components and power amplifiers while maintaining compatibility with traditional single-ended equipment.
Dedicated Headphone Amplifier:
A high-performance current-feedback headphone amplifier circuit provides exceptional drive capability for headphones from 20 to 600 ohms impedance. With an output impedance of just 2.35 ohms and THD below 0.01%, the headphone stage delivers powerful, clean, and controlled sound to even demanding planar magnetic and high-impedance dynamic headphones.
Precision Volume Control:
Volume is controlled by a motorised Alps potentiometer - the gold standard in volume control technology. This can be adjusted via the front panel knob or the included remote control, allowing level adjustments without leaving your listening position. The microprocessor-controlled system ensures smooth, precise volume tracking and channel balance at all levels.
Exceptional Technical Performance:
The Quad 33 preamplifier delivers specifications worthy of its heritage:
- Total Harmonic Distortion: <0.0005% (1kHz, line/XLR inputs)
- Signal-to-Noise Ratio: >108dB (A-weighted, line inputs)
- Frequency Response: 20Hz-20kHz (+/-0.2dB)
- Output Impedance: 120 ohms
These figures represent true high-fidelity performance, ensuring the 33 adds nothing unwanted and subtracts nothing desired from your music.
Designed and Engineered in Britain:
The Quad 33 2024 edition was developed by an internal team at Quad's Huntingdon headquarters in Cambridgeshire, England. Jan Ertner led the electronics design, with Rob Flynn and Paul Conville - both seasoned Quad service engineers - playing crucial roles in revitalizing the new design. David McNeill, Quad's industrial design head for over 20 years, oversaw the aesthetic development, choosing an evolutionary approach rather than a complete overhaul.
The result honors the original's iconic appearance while incorporating LED backlighting, LCD display technology, USB firmware updates, microprocessor control, and modern component quality throughout.
Remarkable Value:
Perhaps most impressive is the pricing. In 1967, a Quad 33 sold for £49 (the 33/303 combination was £98). Adjusted for inflation, that's £1,115 in today's money. Add 20% VAT and the new 33 at £1,199 costs virtually the same in real terms as the original - while delivering vastly superior performance, build quality, and features. It's a genuine bargain for a hand-built British preamplifier of this caliber.
Perfect Partner: Quad 303:
The Quad 33 is designed to work seamlessly with the companion Quad 303 power amplifier (sold separately), recreating the legendary pre/power combination that defined British hi-fi. The 303 delivers 50W per channel in stereo mode or can be bridged to 140W mono for greater power and dynamics.
Technical Specifications
General Description: Stereo Preamplifier / Control Unit
Design: Solid-state analogue circuit with digital microprocessor control
Design Philosophy:
- Illuminated LCD screen with adjustable backlighting
- Dedicated high-performance low-noise MM/MC phono stage
- Classic Quad 'Tilt' adjustment (+/-3dB on 700Hz axis)
- Bass tone control (+/-3dB)
- Balance control
- Dedicated current-feedback headphone amplifier
- Motorised Alps volume potentiometer
- Full remote control functionality
- USB port for firmware updates
Inputs:
- 3 x RCA line-level (single-ended)
- 1 x Balanced XLR (pair)
- 1 x Phono (MM/MC switchable, RCA)
Outputs:
- 1 x RCA Pre Out (single-ended)
- 1 x XLR Pre Out (balanced)
- 1 x RCA AUX Out
- 1 x Headphone (6.35mm / 1/4")
- 2 x 12V Trigger Out
Preamplifier Section:
Gain:
- 0dB (Line / XLR)
- +46dB (Phono MM)
- +63.5dB (Phono MC)
Input Sensitivity (Vout=695mV):
- 695mV (Line / XLR)
- 3.2mV (Phono MM)
- 460μV (Phono MC)
Input Impedance:
- 10kΩ (Line / XLR)
- 47kΩ / 100pF (Phono MM)
- 100Ω / 1.7nF (Phono MC)
Total Harmonic Distortion (THD):
- <0.0005% (1kHz, Line/XLR)
- <0.002% (1kHz, Phono MM / MC)
Frequency Response: 20Hz - 20kHz (+/-0.2dB)
Signal-to-Noise Ratio (S/N):
- 108dB (A-weighted, Line/XLR)
- 82dB (A-weighted, Phono MM)
- 74dB (A-weighted, Phono MC)
Output Impedance: 120 ohms
Headphone Amplifier:
Design: Current-feedback with high slew rate
Total Harmonic Distortion (THD): <0.01% (1kHz, 50mW)
Output Impedance: 2.35 ohms
Load Impedance: 20 - 600 ohms
Physical Specifications:
Dimensions (W x H x D): 258mm x 82.9mm x 165mm (10.2" x 3.3" x 6.5")
Net Weight: 4kg (8.8 lbs)
Gross Weight (with packaging): 4.96kg (10.9 lbs)
Carton Size: 330mm x 192mm x 257mm (13.0" x 7.6" x 10.1")
Finish: Classic Quad Grey (matte silver anodized aluminum)
Standby Power Consumption: <0.5W
Power Requirements: 220-240V ~ 50/60Hz or 100-120V ~ 50/60Hz (region dependent)
What's Included
- Quad 33 Preamplifier
- Power Cord (region appropriate)
- Remote Control
- User Manual
