What tubes does the McIntosh MC275 use?

The McIntosh MC275 uses 1× 12AX7, 2× 12AU7, 2× 12BH7, 2× 12AZ7 preamp tubes and 4× KT88 power tubes.

When was the McIntosh MC275 produced?

The McIntosh MC275 was produced 1961–1971.

McIntosh MC275 preset

Verified · 92/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The McIntosh MC275 is a stereo valve power amplifier rated at 75 watts per channel, introduced in 1961 and later reissued; it is one of the best-known American hi-fi valve amps. A mode switch selects mono, twin or stereo operation. Each side runs a 12AX7 input stage, a 12AU7 phase splitter, a 12BH7 driver and 12AZ7 cathode-follower grid drivers into fixed-bias KT88/6550s on McIntosh Unity Coupled output transformers.

Years produced: 1961–1971
Made in: USA
Wattage: 75W
Channels: 1
Preamp tubes: 1× 12AX7, 2× 12AU7, 2× 12BH7, 2× 12AZ7
Power tubes: 4× KT88

Tags: american, vintage, stereo, power-amp, kt88, clean.

Schematic-derived preset files for 16 Fractal and Line 6 modelers: Axe-Fx II/XL/XL+, Axe-Fx III, FM3, FM9, and the full Helix family (Floor, LT, Rack, HX Stomp, HX Stomp XL, Native).

Gridleak extracts amp parameters from original circuit schematics using AI vision — component values, gain staging, tone stack topology, tube types — then generates native preset files for every supported modeler. Every extraction is scored 0–100 and the score is published.