Предусилители — QUAD 33 Preamplifier

The 33 is an analogue preamplifier from Quad, the British brand, introduced in 2024 as a modern revival of one of its best-known products. The original Quad 33 control unit, launched in 1967 with the 303 power amplifier, sold around 120,000 units before production ended in 1982. The new 33 keeps the original model number, compact dimensions and recognisable styling, but its circuitry, connectivity and construction are entirely new, and it is designed to partner the new 303 power amplifier.

Key specs that matter

The new 33 provides four single-ended RCA inputs and one balanced XLR input, with one balanced XLR output and two single-ended outputs (RCA pre-out and an AUX output). A built-in phono stage switches between moving-magnet and moving-coil operation, with 46dB of gain for MM and 63.5dB for MC. Overall line gain is 29dB. A current-feedback headphone amplifier, two 12V trigger outputs and remote control are included. A motorised knob sets level in the analogue domain, and a backlit orange LCD with adjustable brightness shows status. The front panel is machined and anodised aluminium, on an all-metal chassis.

Engineering and use context

Quad kept the signal path purely analogue - the 33 has no internal DAC, avoiding digital noise inside the chassis - while a microprocessor handles switching, display and remote control. The phono input stage uses ultra-low-noise op-amps with high slew rates and low distortion, and the RIAA equalisation stage has its own dual bipolar/JFET audio op-amp. Switching between MM and MC is done from the controls, whereas the original 33 needed a plug-in adaptor module to match different cartridges and did not cater for moving-coil types at all. The original 1967 unit was built on a steel chassis around five plug-in modules and used DIN connectors throughout. The new version adds balanced XLR input and output, which the original never had, allowing long cable runs to a power amplifier with lower noise pickup. Quad's traditional tone and filter section returns in updated form, including its Tilt control, and it can be bypassed from the remote. The motorised volume knob follows remote commands while keeping the feel of a physical control.

Pairing

The 33 is designed to sit beside the new Quad 303 power amplifier, connected by XLR or RCA, with trigger cables switching the amplifier on with the preamplifier. The built-in MM/MC phono stage suits vinyl-based systems without an external phono stage, and the headphone output makes it usable as a desktop control unit.

Alternatives

Quad's own Artera Pre is a preamplifier with a built-in DAC for systems that need digital inputs.