Quad (Acoustical Manufacturing) · Quad transistor era

Quad 33

The preamplifier that carried Quad through the 1970s; the highest-volume product Quad ever made.

Catalogue code: Quad 33
Years: 1967–1982
Type: solid-state preamplifier
Valves & speakers: Solid-state stereo preamplifier, 120,000 built - the best-selling Quad ever
Lifecycle: retired
Confidence: High

Specifications

Technology: solid-state
Channels: 2
Inputs_outputs: phono/tuner/tape, DIN sockets

Safety

Solid-state: the 33/303 pair runs on a dedicated mains connector - check for the correct power supply and original DIN cabling.

01 / Witnesses

What applies here

Marks that can be entered for this maker: Serial number, Model / catalogue number, British capacitor code (Hunts, Mullard), Japanese capacitor code (Nichicon, Chemi-Con, ELNA), EIA component code, Version & era marker.

02 / Bounds

The model year is a floor

Nothing predates 1967; components only push the date later.

03 / Value

What moves the price

Sold-price aggregates are not collected yet, so the archive gives no figure — condition, originality of the transformers and a documented recap move this model more than any list price.