McIntosh Laboratory · Tube power amplifiers

MC40

A 17-year mono run (1962-1979) - the longest-lived McIntosh tube mono block.

Catalogue code: MC40
Years: 1962–1979
Type: power amplifier (mono)
Valves & speakers: 40 W mono, offered with 6L6GC or 6550 output tubes
Lifecycle: retired
Confidence: Medium

Specifications

Watts: 40
Channels: 1
Technology: tube
Tubes: 2x 6L6GC or 2x 6550, 2x 12AX7

Safety

Tube chassis: lethal B+ voltages remain after switch-off — discharge before service. Never power up an unrestored unit on original electrolytics. Serial tag is an ink stamp on a plastic label (often missing/faded); the value depends on original transformers (replaced/rewound iron cuts price sharply).

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 1962; 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.