MC2105

Power amplifier, McIntosh, 1967

Listed on McIntosh's legacy page as the company's first solid state amplifier, rated at 105 watts per channel and fitted with output autoformers.

A-24, isometric, same camera for both

Drawing: A-24
Introduced: 1967
Produced: 1967 to 1978
Made in: United States
Designed by: Not credited by sources
Launch price: US$799 (first-year price listed by Radiomuseum)
Size: 411 x 181 x 368 mm
Weight: 29.5 kg

The MC2105 entered McIntosh's range in 1967 as a solid state stereo amplifier with 105 watts per channel into 4, 8 or 16 ohms. McIntosh's manual describes 34 silicon transistors, thermal cutouts on the output heat sinks and protection against shorted or open loads. Two large power level meters with dynamic peak locking dominate the front panel. The manual's front panel photographs are black and white, and McIntosh's own heritage page places its signature blue power meters in the 1970s.

Front elevation of the McIntosh MC2105, 411 mm wide and 181 mm high — Front elevation, dimensions in millimetres. Drawn from published dimensions and descriptions; detail is simplified.

Specification

Item	As published
Power output	105 watts minimum sine wave continuous average power per channel into 4, 8 or 16 ohms
Harmonic distortion	0.25% maximum, 250 milliwatts to 105 watts, 20 Hz to 20,000 Hz
Frequency response	20 Hz to 20,000 Hz +0 -0.25 dB; 10 Hz to 100,000 Hz +0 -3.0 dB at one watt
Noise and hum	90 dB below rated output
Semiconductors	34 silicon transistors, 18 silicon rectifiers and diodes
Power requirements	120 volts 50/60 Hz; 75 watts at zero signal, 430 watts at rated output

Out of production

Find an original

The MC2105 is out of production. Originals change hands on the marketplaces listed here; buy restored, or budget for recapping and new valves.

The house

Founded: 1949
Founder: Frank McIntosh and Gordon Gow
Origin: Silver Spring, Maryland, United States (moved to Binghamton, New York, in 1951)
Today: Owned by Bose Corporation through McIntosh Group, after Highlander Partners sold it in a deal announced on 19 November 2024.

Further sheets

Sources

Notes for the record: Blue meters: the brief asked whether the MC2105 introduced McIntosh's blue meters. No source I opened says so. McIntosh's heritage page says only that signature blue amplifier power meters solidified the trademark look in the 1970s, Wikipedia says blue VU meters were used circa 1974 onward, and the MC2105 manual (11-74 edition) describes gold teal nomenclature illumination without mentioning blue meters. The claim is therefore unverified; a dealer listing seen only in search results asserted it. McIntosh's legacy page calls the MC2105 its 1st Solid State Amplifier with autoformers, but the MC250 and MC2505 are also listed with 1967 starts, and Wikipedia calls the MC2505 the first transistor amplifier using autoformers, so which came first is not settled here. Price is Radiomuseum's first-year figure from the contributor's own collection; hifi-wiki lists about 5,115 DM and 1967 to 1977. Dimensions are the manual's front panel width and height and chassis depth (16 3/16, 7 1/8 and 14 1/2 in) converted at 25.4 mm per inch; weight is 65 lb net.